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Lyimo BM, Bakari C, Popkin-Hall ZR, Giesbrecht DJ, Seth MD, Pereus D, Shabani ZI, Moshi R, Boniface R, Mandara CI, Madebe R, Juliano JJ, Bailey JA, Ishengoma DS. Genetic polymorphism and evidence of signatures of selection in the Plasmodium falciparum circumsporozoite protein gene in Tanzanian regions with different malaria endemicity. Malar J 2024; 23:139. [PMID: 38720288 PMCID: PMC11080125 DOI: 10.1186/s12936-024-04974-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 05/03/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND In 2021 and 2023, the World Health Organization approved RTS,S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made of Plasmodium falciparum circumsporozoite protein (PfCSP), but polymorphisms in the gene raise concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed the Pfcsp genetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission intensities in Mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country. METHODS The analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of Mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright's inbreeding coefficient (Fws), Wright's fixation index (FST), principal component analysis, nucleotide diversity, and Tajima's D were used to assess within-host parasite diversity, population structure and natural selection. RESULTS Based on Fws (< 0.95), there was high polyclonality (ranging from 69.23% in Nachingwea to 56.9% in Muheza). No population structure was detected in the Pfcsp gene in the five regions (mean FST = 0.0068). The average nucleotide diversity (π), nucleotide differentiation (K) and haplotype diversity (Hd) in the five regions were 4.19, 0.973 and 0.0035, respectively. The C-terminal region of Pfcsp showed high nucleotide diversity at Th2R and Th3R regions. Positive values for the Tajima's D were observed in the Th2R and Th3R regions consistent with balancing selection. The Pfcsp C-terminal sequences revealed 50 different haplotypes (H_1 to H_50), with only 2% of sequences matching the 3D7 strain haplotype (H_50). Conversely, with the NF54 strain, the Pfcsp C-terminal sequences revealed 49 different haplotypes (H_1 to H_49), with only 0.4% of the sequences matching the NF54 strain (Hap_49). CONCLUSIONS The findings demonstrate high diversity of the Pfcsp gene with limited population differentiation. The Pfcsp gene showed positive Tajima's D values, consistent with balancing selection for variants within Th2R and Th3R regions. The study observed differences between the intended haplotypes incorporated into the design of RTS,S and R21 vaccines and those present in natural parasite populations. Therefore, additional research is warranted, incorporating other regions and more recent data to comprehensively assess trends in genetic diversity within this important gene. Such insights will inform the choice of alleles to be included in the future vaccines.
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Affiliation(s)
- Beatus M Lyimo
- National Institute for Medical Research, Dar es Salaam, Tanzania.
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
| | - Catherine Bakari
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Misago D Seth
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Dativa Pereus
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Zulfa I Shabani
- Dar Es Salaam University College of Education, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Ramadhan Moshi
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ruth Boniface
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Celine I Mandara
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Rashid Madebe
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Deus S Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Harvard T.H Chan School of Public Health, Boston, MA, USA
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia
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2
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Stump WH, Klingenberg HJ, Ott AC, Gonzales DM, Burns JM. Design and Evaluation of Chimeric Plasmodium falciparum Circumsporozoite Protein-Based Malaria Vaccines. Vaccines (Basel) 2024; 12:351. [PMID: 38675734 PMCID: PMC11053680 DOI: 10.3390/vaccines12040351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/19/2024] [Accepted: 03/22/2024] [Indexed: 04/28/2024] Open
Abstract
Efficacy data on two malaria vaccines, RTS,S and R21, targeting Plasmodium falciparum circumsporozoite protein (PfCSP), are encouraging. Efficacy may be improved by induction of additional antibodies to neutralizing epitopes outside of the central immunodominant repeat domain of PfCSP. We designed four rPfCSP-based vaccines in an effort to improve the diversity of the antibody response. We also evaluated P. falciparum merozoite surface protein 8 (PfMSP8) as a malaria-specific carrier protein as an alternative to hepatitis B surface antigen. We measured the magnitude, specificity, subclass, avidity, durability, and efficacy of vaccine-induced antibodies in outbred CD1 mice. In comparison to N-terminal- or C-terminal-focused constructs, immunization with near full-length vaccines, rPfCSP (#1) or the chimeric rPfCSP/8 (#2), markedly increased the breadth of B cell epitopes recognized covering the N-terminal domain, junctional region, and central repeat. Both rPfCSP (#1) and rPfCSP/8 (#2) also elicited a high proportion of antibodies to conformation-dependent epitopes in the C-terminus of PfCSP. Fusion of PfCSP to PfMSP8 shifted the specificity of the T cell response away from PfCSP toward PfMSP8 epitopes. Challenge studies with transgenic Plasmodium yoelii sporozoites expressing PfCSP demonstrated high and consistent sterile protection following rPfCSP/8 (#2) immunization. Of note, antibodies to conformational C-terminal epitopes were not required for protection. These results indicate that inclusion of the N-terminal domain of PfCSP can drive responses to protective, repeat, and non-repeat B cell epitopes and that PfMSP8 is an effective carrier for induction of high-titer, durable anti-PfCSP antibodies.
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Affiliation(s)
| | | | | | | | - James M. Burns
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA; (W.H.S.); (H.J.K.); (A.C.O.); (D.M.G.)
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3
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Lyimo BM, Bakari C, Popkin-Hall ZR, Giesbrecht DJ, Seth MD, Pereus D, Moshi R, Boniface R, Mandara CI, Madebe R, Juliano JJ, Bailey JA, Ishengoma DS. Genetic polymorphism and evidence of signatures of selection in the Plasmodium falciparum circumsporozoite protein gene in Tanzanian regions with different malaria endemicity. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.23.24301587. [PMID: 38343796 PMCID: PMC10854334 DOI: 10.1101/2024.01.23.24301587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Background In 2021 and 2023, the World Health Organization approved RTS, S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made of Plasmodium falciparum circumsporozoite protein (Pfcsp) but polymorphisms in this gene raises concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed the Pfcsp genetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission in mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country. Methods The analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright's inbreeding coefficient (Fws), Wright's fixation index (FST), principal component analysis, nucleotide diversity, and Tajima's D were used to assess within-host parasite diversity, population structure and natural selection. Results Based on Fws (< 0.95), there was high polyclonality (ranged from 69.23% in Nachingwea to 56.9% in Muheza). No population structure was detected in the Pfcsp gene in the five regions (mean FST= 0.0068). The average nucleotide diversity (π), nucleotide differentiation (K) and haplotype diversity (Hd) in the five regions were 4.19, 0.973 and 0.0035, respectively. The C-terminal region of Pfcsp showed high nucleotide diversity at Th2R and Th3R regions. Positive values for the Tajima's D were observed in the Th2R and Th3R regions consistent with balancing selection. The Pfcsp C-terminal sequences had 50 different haplotypes (H_1 to H_50) and only 2% of sequences matched the 3D7 strain haplotype (H_50). Conclusions The findings demonstrate high diversity of the Pfcsp gene with limited population differentiation. The Pfcsp gene showed positive Tajima's D values for parasite populations, consistent with balancing selection for variants within Th2R and Th3R regions. This data is consistent with other studies conducted across Africa and worldwide, which demonstrate low 3D7 haplotypes and little population structure. Therefore, additional research is warranted, incorporating other regions and more recent data to comprehensively assess trends in genetic diversity within this important gene. Such insights will inform the choice of alleles to be included in the future vaccines.
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Affiliation(s)
- Beatus M. Lyimo
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Catherine Bakari
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Misago D. Seth
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Dativa Pereus
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Ramadhan Moshi
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ruth Boniface
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | | | - Rashid Madebe
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Deus S. Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Harvard T.H Chan School of Public Health, Boston, MA, USA
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia
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Naghizadeh M, Singh SK, Plieskatt J, Ofori EA, Theisen M. Production and Purification of Plasmodium Circumsporozoite Protein in Lactococcus lactis. Methods Mol Biol 2024; 2762:109-121. [PMID: 38315362 DOI: 10.1007/978-1-0716-3666-4_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Malaria is a vector-borne disease caused by Plasmodium parasites of which Plasmodium falciparum contributed to an estimated 247 million cases worldwide in 2021 (WHO malaria report 2022). The P. falciparum Circumsporozoite protein (PfCSP) covers the surface of the sporozoite which is critical to cell invasion in the human host. PfCSP is the leading pre-erythrocytic vaccine candidate and forms the basis of the RTS'S (Mosquirix®) malaria vaccine. However, high-yield production of full-length PfCSP with proper folding has been challenging. Here, we describe expression and purification of full-length PfCSP (containing 4 NVDP and 38 NANP repeats) with proper conformation by a simple three-step procedure in the Lactococcus lactis expression system.
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Affiliation(s)
- Mohammad Naghizadeh
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Susheel K Singh
- Biotherapeutic and Vaccine Research Division, ICMR-Regional Medical Research Centre, Bhubaneswar, Odisha, India
| | - Jordan Plieskatt
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Ebenezer Addo Ofori
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
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5
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Geens R, Stanisich J, Beyens O, D'Hondt S, Thiberge J, Ryckebosch A, De Groot A, Magez S, Vertommen D, Amino R, De Winter H, Volkov AN, Tompa P, Sterckx YG. Biophysical characterization of the Plasmodium falciparum circumsporozoite protein's N-terminal domain. Protein Sci 2024; 33:e4852. [PMID: 38059674 PMCID: PMC10749493 DOI: 10.1002/pro.4852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 11/28/2023] [Accepted: 12/04/2023] [Indexed: 12/08/2023]
Abstract
The circumsporozoite protein (CSP) is the main surface antigen of the Plasmodium sporozoite (SPZ) and forms the basis of the currently only licensed anti-malarial vaccine (RTS,S/AS01). CSP uniformly coats the SPZ and plays a pivotal role in its immunobiology, in both the insect and the vertebrate hosts. Although CSP's N-terminal domain (CSPN ) has been reported to play an important role in multiple CSP functions, a thorough biophysical and structural characterization of CSPN is currently lacking. Here, we present an alternative method for the recombinant production and purification of CSPN from Plasmodium falciparum (PfCSPN ), which provides pure, high-quality protein preparations with high yields. Through an interdisciplinary approach combining in-solution experimental methods and in silico analyses, we provide strong evidence that PfCSPN is an intrinsically disordered region displaying some degree of compaction.
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Affiliation(s)
- Rob Geens
- Laboratory of Medical Biochemistry (LMB)University of AntwerpAntwerpBelgium
- Structural Biology BrusselsVrije Universiteit BrusselBrusselsBelgium
| | - Jessica Stanisich
- Cellular and Molecular ImmunologyVrije Universiteit BrusselBrusselsBelgium
| | - Olivier Beyens
- Laboratory of Medicinal Chemistry (UAMC)University of AntwerpAntwerpBelgium
| | - Stijn D'Hondt
- Laboratory of Medicinal Chemistry (UAMC)University of AntwerpAntwerpBelgium
| | | | - Amber Ryckebosch
- Laboratory of Medical Biochemistry (LMB)University of AntwerpAntwerpBelgium
| | - Anke De Groot
- Laboratory of Medical Biochemistry (LMB)University of AntwerpAntwerpBelgium
| | - Stefan Magez
- Cellular and Molecular ImmunologyVrije Universiteit BrusselBrusselsBelgium
- Ghent University Global CampusIncheonSouth Korea
| | - Didier Vertommen
- de Duve Institute and MASSPROT Platform, UCLouvainBrusselsBelgium
| | - Rogerio Amino
- Unit of Malaria Infection & ImmunityInstitut PasteurParisFrance
| | - Hans De Winter
- Laboratory of Medicinal Chemistry (UAMC)University of AntwerpAntwerpBelgium
| | - Alexander N. Volkov
- Structural Biology BrusselsVrije Universiteit BrusselBrusselsBelgium
- VIB‐VUB Center for Structural BiologyVlaams Instituut voor Biotechnologie (VIB)BrusselsBelgium
- Jean Jeener NMR CentreVrije Universiteit BrusselBrusselsBelgium
| | - Peter Tompa
- Structural Biology BrusselsVrije Universiteit BrusselBrusselsBelgium
- VIB‐VUB Center for Structural BiologyVlaams Instituut voor Biotechnologie (VIB)BrusselsBelgium
- Institute of Enzymology, Biological Research CenterHungarian Academy of SciencesBudapestHungary
| | - Yann G.‐J. Sterckx
- Laboratory of Medical Biochemistry (LMB)University of AntwerpAntwerpBelgium
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6
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Borkens Y. Malaria & mRNA Vaccines: A Possible Salvation from One of the Most Relevant Infectious Diseases of the Global South. Acta Parasitol 2023; 68:916-928. [PMID: 37828249 PMCID: PMC10665248 DOI: 10.1007/s11686-023-00712-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 08/01/2023] [Indexed: 10/14/2023]
Abstract
Malaria is one of the most dangerous infectious diseases in the world. It occurs in tropical and subtropical regions and affects about 40% of the world´s population. In endemic regions, an estimated 200 million people contract malaria each year. Three-quarters of all global deaths (about 600 per year) are children under 5 years of age. Thus, malaria is one of the most relevant tropical and also childhood diseases in the world. Thanks to various public health measures such as vector control through mosquito nets or the targeted use of insecticides as well as the use of antimalarial prophylaxis drugs, the incidence has already been successfully reduced in recent years. However, to reduce the risk of malaria and to protect children effectively, further measures are necessary. An important part of these measures is an effective vaccination against malaria. However, the history of research shows that the development of an effective malaria vaccine is not an easy undertaking and is associated with some complications. Research into possible vaccines began as early as the 1960s. However, the results achieved were rather sobering and the various vaccines fell short of their expectations. It was not until 2015 that the vaccine RTS,S/AS01 received a positive evaluation from the European Medicines Agency. Since then, the vaccine has been tested in Africa. However, with the COVID-19 pandemic, there are new developments in vaccine research that could also benefit malaria research. These include, among others, the so-called mRNA vaccines. Already in the early 1990s, an immune response triggered by an mRNA vaccine was described for the first time. Since then, mRNA vaccines have been researched and discussed for possible prophylaxis. However, it was not until the COVID-19 pandemic that these vaccines experienced a veritable progress. mRNA vaccines against SARS-CoV-2 were rapidly developed and achieved high efficacy in studies. Based on this success, it is not surprising that companies are also focusing on other diseases and pathogens. Besides viral diseases, such as influenza or AIDS, malaria is high on this list. Many pharmaceutical companies (including the German companies BioNTech and CureVac) have already confirmed that they are researching mRNA vaccines against malaria. However, this is not an easy task. The aim of this article is to describe and discuss possible antigens that could be considered for mRNA vaccination. However, this topic is currently still very speculative.
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Affiliation(s)
- Yannick Borkens
- Charité, Charitéplatz 1, 10117, Berlin, Germany.
- Humboldt-Universität zu Berlin, Unter den Linden 6, 10117, Berlin, Germany.
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7
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Martin GM, Torres JL, Pholcharee T, Oyen D, Flores-Garcia Y, Gibson G, Moskovitz R, Beutler N, Jung DD, Copps J, Lee WH, Gonzalez-Paez G, Emerling D, MacGill RS, Locke E, King CR, Zavala F, Wilson IA, Ward AB. Affinity-matured homotypic interactions induce spectrum of PfCSP structures that influence protection from malaria infection. Nat Commun 2023; 14:4546. [PMID: 37507365 PMCID: PMC10382551 DOI: 10.1038/s41467-023-40151-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
The generation of high-quality antibody responses to Plasmodium falciparum (Pf) circumsporozoite protein (PfCSP), the primary surface antigen of Pf sporozoites, is paramount to the development of an effective malaria vaccine. Here we present an in-depth structural and functional analysis of a panel of potent antibodies encoded by the immunoglobulin heavy chain variable (IGHV) gene IGHV3-33, which is among the most prevalent and potent antibody families induced in the anti-PfCSP immune response and targets the Asn-Ala-Asn-Pro (NANP) repeat region. Cryo-electron microscopy (cryo-EM) reveals a remarkable spectrum of helical antibody-PfCSP structures stabilized by homotypic interactions between tightly packed fragments antigen binding (Fabs), many of which correlate with somatic hypermutation. We demonstrate a key role of these mutated homotypic contacts for high avidity binding to PfCSP and in protection from Pf malaria infection. Together, these data emphasize the importance of anti-homotypic affinity maturation in the frequent selection of IGHV3-33 antibodies and highlight key features underlying the potent protection of this antibody family.
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Affiliation(s)
- Gregory M Martin
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Jonathan L Torres
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Tossapol Pholcharee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- Department of Biochemistry, University of Oxford, Oxford, OX1 3DR, UK
| | - David Oyen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- Pfizer Inc, San Diego, CA, 92121, USA
| | - Yevel Flores-Garcia
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Grace Gibson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Re'em Moskovitz
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Nathan Beutler
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Diana D Jung
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Jeffrey Copps
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Wen-Hsin Lee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Gonzalo Gonzalez-Paez
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | | | | | - Emily Locke
- PATH's Malaria Vaccine Initiative, Washington, DC, 20001, USA
| | - C Richter King
- PATH's Malaria Vaccine Initiative, Washington, DC, 20001, USA
| | - Fidel Zavala
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.
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8
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Pendyala G, Calvo‐Calle JM, Moreno A, Kane RS. A multivalent Plasmodium falciparum circumsporozoite protein-based nanoparticle malaria vaccine elicits a robust and durable antibody response against the junctional epitope and the major repeats. Bioeng Transl Med 2023; 8:e10514. [PMID: 37476056 PMCID: PMC10354751 DOI: 10.1002/btm2.10514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 02/27/2023] [Accepted: 03/08/2023] [Indexed: 03/30/2023] Open
Abstract
Plasmodium falciparum (Pf) malaria continues to cause considerable morbidity and mortality worldwide. The circumsporozoite protein (CSP) is a particularly attractive candidate for designing vaccines that target sporozoites-the first vertebrate stage in a malaria infection. Current PfCSP-based vaccines, however, do not include epitopes that have recently been shown to be the target of potent neutralizing antibodies. We report the design of a SpyCatcher-mi3-nanoparticle-based vaccine presenting multiple copies of a chimeric PfCSP (cPfCSP) antigen that incorporates these important "T1/junctional" epitopes as well as a reduced number of (NANP)n repeats. cPfCSP-SpyCatcher-mi3 was immunogenic in mice eliciting high and durable IgG antibody levels as well as a balanced antibody response against the T1/junctional region and the (NANP)n repeats. Notably, the antibody concentration elicited by immunization was significantly greater than the reported protective threshold defined in a murine challenge model. Refocusing the immune response toward functionally relevant subdominant epitopes to induce a more balanced and durable immune response may enable the design of a more effective second generation PfCSP-based vaccine.
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Affiliation(s)
- Geetanjali Pendyala
- School of Chemical & Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGeorgia30332USA
| | - J. Mauricio Calvo‐Calle
- Department of PathologyUniversity of Massachusetts Medical SchoolWorcesterMassachusetts01655USA
| | - Alberto Moreno
- Emory Vaccine Center, Emory National Primate Research CenterEmory UniversityAtlantaGeorgia30329USA
- Division of Infectious Diseases, Department of MedicineEmory UniversityAtlantaGeorgia30303USA
| | - Ravi S. Kane
- School of Chemical & Biomolecular EngineeringGeorgia Institute of TechnologyAtlantaGeorgia30332USA
- Wallace H. Coulter Department of Biomedical EngineeringGeorgia Institute of TechnologyAtlantaGeorgia30332USA
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9
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Kekani LN, Witika BA. Current advances in nanodrug delivery systems for malaria prevention and treatment. DISCOVER NANO 2023; 18:66. [PMID: 37382765 PMCID: PMC10409709 DOI: 10.1186/s11671-023-03849-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 04/13/2023] [Indexed: 06/30/2023]
Abstract
Malaria is a life-threatening, blood-borne disease with over two hundred million cases throughout the world and is more prevalent in Sub-Saharan Africa than anywhere else in the world. Over the years, several treatment agents have been developed for malaria; however, most of these active pharmaceutical ingredients exhibit poor aqueous solubility and low bioavailability and may result in drug-resistant parasites, thus increasing malaria cases and eventually, deaths. Factors such as these in therapeutics have led to a better appreciation of nanomaterials. The ability of nanomaterials to function as drug carriers with a high loading capacity and targeted drug delivery, good biocompatibility, and low toxicity renders them an appealing alternative to conventional therapy. Nanomaterials such as dendrimers and liposomes have been demonstrated to be capable of enhancing the efficacy of antimalarial drugs. This review discusses the recent development of nanomaterials and their benefits in drug delivery for the potential treatment of malaria.
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Affiliation(s)
- Linda N Kekani
- Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Pretoria, 0208, South Africa
| | - Bwalya A Witika
- Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Pretoria, 0208, South Africa.
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10
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Wang J, Chen K, Ren Q, Zhang S, Yang J, Wang Y, Nian Y, Li X, Liu G, Luo J, Yin H, Guan G. Comparative genomics reveals unique features of two Babesia motasi subspecies: Babesia motasi lintanensis and Babesia motasi hebeiensis. Int J Parasitol 2023; 53:265-283. [PMID: 37004737 DOI: 10.1016/j.ijpara.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 02/05/2023] [Accepted: 02/12/2023] [Indexed: 04/03/2023]
Abstract
Parasites of the Babesia genus are prevalent worldwide and infect a wide diversity of domestic animals and humans. Herein, using Oxford Nanopore Technology and Illumina sequencing technologies, we sequenced two Babesia sub-species, Babesia motasi lintanensis and Babesia motasi hebeiensis. We identified 3,815 one-to-one ortholog genes that are specific to ovine Babesia spp. Phylogenetic analysis reveals that the two B. motasi subspecies form a distinct clade from other Piroplasma spp. Consistent with their phylogenetic position, comparative genomic analysis reveals that these two ovine Babesia spp. share higher colinearity with Babesia bovis than with Babesia microti. Concerning the speciation date, B. m. lintanensis split from B. m. hebeiensis approximately 17 million years ago. Genes correlated to transcription, translation, protein modification and degradation, as well as differential/specialized gene family expansions in these two subspecies may favor adaptation to vertebrate and tick hosts. The close relationship between B. m. lintanensis and B. m. hebeiensis is underlined by a high degree of genomic synteny. Compositions of most invasion, virulence, development, and gene transcript regulation-related multigene families, including spherical body protein, variant erythrocyte surface antigen, glycosylphosphatidylinositol anchored proteins, and transcription factor Apetala 2 genes, is largely conserved, but in contrast to this conserved situation, we observe major differences in species-specific genes that may be involved in multiple functions in parasite biology. For the first time in Babesia spp., we find abundant fragments of long terminal repeat-retrotransposons in these two species. We provide fundamental information to characterize the genomes of B. m. lintanensis and B. m. hebeiensis, providing insights into the evolution of B. motasi group parasites.
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Affiliation(s)
- Jinming Wang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China.
| | - Kai Chen
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Qiaoyun Ren
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China.
| | - Shangdi Zhang
- Department of Clinical Laboratory, The Second Hospital of Lanzhou University, Lanzhou, China.
| | - Jifei Yang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China.
| | - Yanbo Wang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China; Department of Clinical Laboratory, The Second Hospital of Lanzhou University, Lanzhou, China.
| | - Yueli Nian
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China; Department of Clinical Laboratory, The Second Hospital of Lanzhou University, Lanzhou, China.
| | - Xiaoyun Li
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China.
| | - Guangyuan Liu
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China.
| | - Jianxun Luo
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China.
| | - Hong Yin
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou University, Yangzhou 225009, China.
| | - Guiquan Guan
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Science, Lanzhou, Gansu 730046, China.
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11
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Hayashi CTH, Cao Y, Clark LC, Tripathi AK, Zavala F, Dwivedi G, Knox J, Alameh MG, Lin PJC, Tam YK, Weissman D, Kumar N. mRNA-LNP expressing PfCSP and Pfs25 vaccine candidates targeting infection and transmission of Plasmodium falciparum. NPJ Vaccines 2022; 7:155. [PMID: 36456563 PMCID: PMC9715627 DOI: 10.1038/s41541-022-00577-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/03/2022] [Indexed: 12/03/2022] Open
Abstract
Malaria is a deadly disease responsible for between 550,000 and 627,000 deaths annually. There is a pressing need to develop vaccines focused on malaria elimination. The complex lifecycle of Plasmodium falciparum provides opportunities not only to target the infectious sporozoite stage, introduced by anopheline mosquitoes, but also the sexual stages, which are ingested by mosquitoes during blood feeding, leading to parasite transmission. It is widely recognized that a vaccine targeting multiple stages would induce efficacious transmission reducing immunity. Technological advancements offer new vaccine platforms, such as mRNA-LNPs, which can be used to develop highly effective malarial vaccines. We evaluated the immunogenicity of two leading P. falciparum vaccine candidates, Pfs25 and PfCSP, delivered as mRNA-LNP vaccines. Both vaccines induced extremely potent immune responses when administered alone or in combination, which were superior to Pfs25 and PfCSP DNA vaccine formulations. Purified IgGs from Pfs25 mRNA-LNPs immunized mice were highly potent in reducing malaria transmission to mosquitoes. Additionally, mice after three and four immunizations with PfCSP mRNA-LNP provided evidence for varying degrees of protection against sporozoite challenge. The comparison of immune responses and stage-specific functional activity induced by each mRNA-LNP vaccine, administered alone or in combination, also supports the development of an effective combination vaccine without any risk of immune interference for targeting malaria parasites at various life cycle stages. A combination of vaccines targeting both the infective stage and sexual/midgut stages is expected to interrupt malaria transmission, which is critical for achieving elimination goals.
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Affiliation(s)
- Clifford T H Hayashi
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC, 20052, USA
| | - Yi Cao
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC, 20052, USA
| | - Leor C Clark
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC, 20052, USA
| | - Abhai K Tripathi
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21215, USA
| | - Fidel Zavala
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21215, USA
| | - Garima Dwivedi
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - James Knox
- Department of Pathology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | | | | | - Ying K Tam
- Acuitas Therapeutics, Vancouver, BC, Canada
| | - Drew Weissman
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Nirbhay Kumar
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC, 20052, USA.
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12
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Borkens Y. Malaria-Antigene in der Ära der mRNA-Impfstoffe. Monatsschr Kinderheilkd 2022; 170:828-838. [PMID: 35855690 PMCID: PMC9281189 DOI: 10.1007/s00112-022-01554-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/25/2022] [Indexed: 11/28/2022]
Abstract
ZusammenfassungBereits in den frühen 1990er-Jahren wurde erstmals eine durch einen mRNA-Impfstoff ausgelöste Immunantwort beschrieben. Seitdem wurden mRNA-Impfstoffe für eine mögliche Prophylaxe erforscht und diskutiert. Doch erst mit der COVID-19-Pandemie erlebten diese Impfstoffe einen wahren Boom. Die ersten mRNA-Impfstoffe wurden gegen SARS-CoV‑2 zugelassen und zeigten große Erfolge. Es ist daher nicht verwunderlich, dass sich die Hersteller auch auf andere Krankheiten und Pathogene konzentrieren. Neben viralen Krankheiten wie Influenza oder Aids steht Malaria weit oben auf dieser Liste. Viele Pharmaunternehmen (u. a. die deutschen Unternehmen BioNTech und CureVac) haben bereits bestätigt, an mRNA-Impfstoffen gegen Malaria zu forschen. Dabei ist die Entwicklung eines funktionierenden Impfstoffes gegen Malaria kein leichtes Unterfangen. Seit den 1960ern wird an möglichen Impfstoffen geforscht. Die Ergebnisse sind dabei eher ernüchternd. Erst 2015 erhielt der Impfstoff RTS,S/AS01 eine positive Bewertung der Europäischen Arzneimittel-Agentur. Seitdem wird der Impfstoff in Afrika getestet.
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Affiliation(s)
- Yannick Borkens
- College of Public Health, Medical and Veterinary Science, James Cook University, 1 James Cook Drive, 4811 Townsville, Queensland Australien
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13
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Aleshnick M, Florez-Cuadros M, Martinson T, Wilder BK. Monoclonal antibodies for malaria prevention. Mol Ther 2022; 30:1810-1821. [PMID: 35395399 PMCID: PMC8979832 DOI: 10.1016/j.ymthe.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/04/2022] [Accepted: 04/01/2022] [Indexed: 11/29/2022] Open
Abstract
Monoclonal antibodies are highly specific proteins that are cloned from a single B cell and bind to a single epitope on a pathogen. These laboratory-made molecules can serve as prophylactics or therapeutics for infectious diseases and have an impressive capacity to modulate the progression of disease, as demonstrated for the first time on a large scale during the COVID-19 pandemic. The high specificity and natural starting point of monoclonal antibodies afford an encouraging safety profile, yet the high cost of production remains a major limitation to their widespread use. While a monoclonal antibody approach to abrogating malaria infection is not yet available, the unique life cycle of the malaria parasite affords many opportunities for such proteins to act, and preliminary research into the efficacy of monoclonal antibodies in preventing malaria infection, disease, and transmission is encouraging. This review examines the current status and future outlook for monoclonal antibodies against malaria in the context of the complex life cycle and varied antigenic targets expressed in the human and mosquito hosts, and provides insight into the strengths and limitations of this approach to curtailing one of humanity’s oldest and deadliest diseases.
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Affiliation(s)
- Maya Aleshnick
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | | | - Thomas Martinson
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA
| | - Brandon K Wilder
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, USA; Department of Parasitology, U.S. Naval Medical Research 6 (NAMRU-6), Lima, Peru
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14
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Liu Y, He ZQ, Wang D, Hu YB, Qian D, Yang CY, Zhou RM, Li SH, Lu DL, Zhang HW. One Health approach to improve the malaria elimination programme in Henan Province. ADVANCES IN PARASITOLOGY 2022; 116:153-186. [PMID: 35752447 DOI: 10.1016/bs.apar.2022.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
One Health is a collaborative, multi-sectoral, trans-disciplinary approach with the goal of achieving optimal health outcomes by recognizing the interconnection between people, animals, plants, and the environment and determining how this relates to the control of infectious diseases such as malaria, schistosomiasis and so on. Malarias caused by Plasmodium that commonly infects female Anopheles mosquitoes, which feed on human blood and act as a disease vector. It has been a worldwide important public health problem from ancient times. Also, malaria is one of the infectious diseases with the longest epidemic time and the most serious harm in the history of Henan Province, China. During the past decades, the multi-sectoral, cross-regional, and multi-disciplinary One Health approach contributed to a significant reduction in malaria incidence, resulting in initiation of the Henan Malaria Elimination Action Plan. Herein, we reviewed the history of the fight against malaria in Henan Province. A full picture of malaria epidemics, prevention, and control strategies were showed, with the objective that it will help stakeholders, and policy-makers to take informed decisions on public health issues and intervention designs on malaria control towards elimination in the similar areas.
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Affiliation(s)
- Ying Liu
- Henan Center for Disease Control and Prevention, Zhengzhou, Henan, PR China
| | - Zhi-Quan He
- Henan Center for Disease Control and Prevention, Zhengzhou, Henan, PR China
| | - Dan Wang
- Henan Center for Disease Control and Prevention, Zhengzhou, Henan, PR China
| | - Ya-Bo Hu
- Zhengzhou University, Zhengzhou, Henan, PR China
| | - Dan Qian
- Henan Center for Disease Control and Prevention, Zhengzhou, Henan, PR China
| | - Cheng-Yun Yang
- Henan Center for Disease Control and Prevention, Zhengzhou, Henan, PR China
| | - Rui-Min Zhou
- Henan Center for Disease Control and Prevention, Zhengzhou, Henan, PR China
| | - Su-Hua Li
- Henan Center for Disease Control and Prevention, Zhengzhou, Henan, PR China
| | - De-Ling Lu
- Henan Center for Disease Control and Prevention, Zhengzhou, Henan, PR China
| | - Hong-Wei Zhang
- Henan Center for Disease Control and Prevention, Zhengzhou, Henan, PR China.
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15
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Beutler N, Pholcharee T, Oyen D, Flores-Garcia Y, MacGill RS, Garcia E, Calla J, Parren M, Yang L, Volkmuth W, Locke E, Regules JA, Dutta S, Emerling D, Early AM, Neafsey DE, Winzeler EA, King CR, Zavala F, Burton DR, Wilson IA, Rogers TF. A novel CSP C-terminal epitope targeted by an antibody with protective activity against Plasmodium falciparum. PLoS Pathog 2022; 18:e1010409. [PMID: 35344575 PMCID: PMC8989322 DOI: 10.1371/journal.ppat.1010409] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 04/07/2022] [Accepted: 03/02/2022] [Indexed: 11/19/2022] Open
Abstract
Potent and durable vaccine responses will be required for control of malaria caused by Plasmodium falciparum (Pf). RTS,S/AS01 is the first, and to date, the only vaccine that has demonstrated significant reduction of clinical and severe malaria in endemic cohorts in Phase 3 trials. Although the vaccine is protective, efficacy declines over time with kinetics paralleling the decline in antibody responses to the Pf circumsporozoite protein (PfCSP). Although most attention has focused on antibodies to repeat motifs on PfCSP, antibodies to other regions may play a role in protection. Here, we expressed and characterized seven monoclonal antibodies to the C-terminal domain of CSP (ctCSP) from volunteers immunized with RTS,S/AS01. Competition and crystal structure studies indicated that the antibodies target two different sites on opposite faces of ctCSP. One site contains a polymorphic region (denoted α-ctCSP) and has been previously characterized, whereas the second is a previously undescribed site on the conserved β-sheet face of the ctCSP (denoted β-ctCSP). Antibodies to the β-ctCSP site exhibited broad reactivity with a diverse panel of ctCSP peptides whose sequences were derived from field isolates of P. falciparum whereas antibodies to the α-ctCSP site showed very limited cross reactivity. Importantly, an antibody to the β-site demonstrated inhibition activity against malaria infection in a murine model. This study identifies a previously unidentified conserved epitope on CSP that could be targeted by prophylactic antibodies and exploited in structure-based vaccine design.
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Affiliation(s)
- Nathan Beutler
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Tossapol Pholcharee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - David Oyen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Yevel Flores-Garcia
- Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Randall S. MacGill
- PATH’s Malaria Vaccine Initiative, Washington, District of Columbia, United States of America
| | - Elijah Garcia
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Jaeson Calla
- Department of Pediatrics, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Mara Parren
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Linlin Yang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Wayne Volkmuth
- Atreca Inc., South San Francisco, California, United States of America
| | - Emily Locke
- PATH’s Malaria Vaccine Initiative, Washington, District of Columbia, United States of America
| | - Jason A. Regules
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Sheetij Dutta
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Daniel Emerling
- Atreca Inc., South San Francisco, California, United States of America
| | - Angela M. Early
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Daniel E. Neafsey
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Elizabeth A. Winzeler
- Department of Pediatrics, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - C. Richter King
- PATH’s Malaria Vaccine Initiative, Washington, District of Columbia, United States of America
| | - Fidel Zavala
- Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Dennis R. Burton
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard University, Cambridge, Massachusetts, United States of America
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Thomas F. Rogers
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, United States of America
- Division of Infectious Diseases, Department of Medicine, University of California, San Diego, La Jolla, California, United States of America
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16
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Wang LT, Hurlburt NK, Schön A, Flynn BJ, Flores-Garcia Y, Pereira LS, Kiyuka PK, Dillon M, Bonilla B, Zavala F, Idris AH, Francica JR, Pancera M, Seder RA. The light chain of the L9 antibody is critical for binding circumsporozoite protein minor repeats and preventing malaria. Cell Rep 2022; 38:110367. [PMID: 35172158 PMCID: PMC8896312 DOI: 10.1016/j.celrep.2022.110367] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/17/2021] [Accepted: 01/20/2022] [Indexed: 01/23/2023] Open
Abstract
L9 is a potent human monoclonal antibody (mAb) that preferentially binds two adjacent NVDP minor repeats and cross-reacts with NANP major repeats of the Plasmodium falciparum circumsporozoite protein (PfCSP) on malaria-infective sporozoites. Understanding this mAb's ontogeny and mechanisms of binding PfCSP will facilitate vaccine development. Here, we isolate mAbs clonally related to L9 and show that this B cell lineage has baseline NVDP affinity and evolves to acquire NANP reactivity. Pairing the L9 kappa light chain (L9κ) with clonally related heavy chains results in chimeric mAbs that cross-link two NVDPs, cross-react with NANP, and more potently neutralize sporozoites in vivo compared with their original light chain. Structural analyses reveal that the chimeric mAbs bound minor repeats in a type-1 β-turn seen in other repeat-specific antibodies. These data highlight the importance of L9κ in binding NVDP on PfCSP to neutralize sporozoites and suggest that PfCSP-based immunogens might be improved by presenting ≥2 NVDPs.
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Affiliation(s)
- Lawrence T Wang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicholas K Hurlburt
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Arne Schön
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Barbara J Flynn
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yevel Flores-Garcia
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Lais S Pereira
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Patience K Kiyuka
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marlon Dillon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Brian Bonilla
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Fidel Zavala
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Azza H Idris
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joseph R Francica
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marie Pancera
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
| | - Robert A Seder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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17
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Bacillus subtilis spores as delivery system for nasal Plasmodium falciparum circumsporozoite surface protein immunization in a murine model. Sci Rep 2022; 12:1531. [PMID: 35087102 PMCID: PMC8795416 DOI: 10.1038/s41598-022-05344-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 11/29/2021] [Indexed: 11/15/2022] Open
Abstract
Malaria remains a widespread public health problem in tropical and subtropical regions around the world, and there is still no vaccine available for full protection. In recent years, it has been observed that spores of Bacillus subtillis can act as a vaccine carrier and adjuvant, promoting an elevated humoral response after co-administration with antigens either coupled or integrated to their surface. In our study, B. subtillis spores from the KO7 strain were used to couple the recombinant CSP protein of P. falciparum (rPfCSP), and the nasal humoral-induced immune response in Balb/C mice was evaluated. Our results demonstrate that the spores coupled to rPfCSP increase the immunogenicity of the antigen, which induces high levels of serum IgG, and with balanced Th1/Th2 immune response, being detected antibodies in serum samples for 250 days. Therefore, the use of B. subtilis spores appears to be promising for use as an adjuvant in a vaccine formulation.
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18
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Langowski MD, Khan FA, Savransky S, Brown DR, Balasubramaniyam A, Harrison WB, Zou X, Beck Z, Matyas GR, Regules JA, Miller R, Soisson LA, Batchelor AH, Dutta S. Restricted valency (NPNA) n repeats and junctional epitope-based circumsporozoite protein vaccines against Plasmodium falciparum. NPJ Vaccines 2022; 7:13. [PMID: 35087099 PMCID: PMC8795123 DOI: 10.1038/s41541-022-00430-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 12/14/2021] [Indexed: 12/02/2022] Open
Abstract
The Circumsporozoite Protein (CSP) of Plasmodium falciparum contains an N-terminal region, a conserved Region I (RI), a junctional region, 25-42 copies of major (NPNA) and minor repeats followed by a C-terminal domain. The recently approved malaria vaccine, RTS,S/AS01 contains NPNAx19 and the C-terminal region of CSP. The efficacy of RTS,S against natural infection is low and short-lived, and mapping epitopes of inhibitory monoclonal antibodies may allow for rational improvement of CSP vaccines. Tobacco Mosaic Virus (TMV) was used here to display the junctional epitope (mAb CIS43), Region I (mAb 5D5), NPNAx5, and NPNAx20 epitope of CSP (mAbs 317 and 580). Protection studies in mice revealed that Region I did not elicit protective antibodies, and polyclonal antibodies against the junctional epitope showed equivalent protection to NPNAx5. Combining the junctional and NPNAx5 epitopes reduced immunogenicity and efficacy, and increasing the repeat valency to NPNAx20 did not improve upon NPNAx5. TMV was confirmed as a versatile vaccine platform for displaying small epitopes defined by neutralizing mAbs. We show that polyclonal antibodies against engineered VLPs can recapitulate the binding specificity of the mAbs and immune-focusing by reducing the structural complexity of an epitope may be superior to immune-broadening as a vaccine design approach. Most importantly the junctional and restricted valency NPNA epitopes can be the basis for developing highly effective second-generation malaria vaccine candidates.
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Affiliation(s)
- Mark D Langowski
- Structural Vaccinology Lab, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Farhat A Khan
- Structural Vaccinology Lab, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Sofya Savransky
- Structural Vaccinology Lab, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Dallas R Brown
- Structural Vaccinology Lab, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Arasu Balasubramaniyam
- Structural Vaccinology Lab, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - William B Harrison
- Structural Vaccinology Lab, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Xiaoyan Zou
- Malaria Department, Naval Medical Research Center, Silver Spring, MD, USA
| | - Zoltan Beck
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
- Pfizer, 401N Middletown Rd, Pearl River, NY, 10965, USA
| | - Gary R Matyas
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Jason A Regules
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Robin Miller
- United States Agency for International Development, Washington, DC, USA
| | | | - Adrian H Batchelor
- Structural Vaccinology Lab, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Sheetij Dutta
- Structural Vaccinology Lab, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
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19
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Wang LT, Pereira LS, Kiyuka PK, Schön A, Kisalu NK, Vistein R, Dillon M, Bonilla BG, Molina-Cruz A, Barillas-Mury C, Tan J, Idris AH, Francica JR, Seder RA. Protective effects of combining monoclonal antibodies and vaccines against the Plasmodium falciparum circumsporozoite protein. PLoS Pathog 2021; 17:e1010133. [PMID: 34871332 PMCID: PMC8675929 DOI: 10.1371/journal.ppat.1010133] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 12/16/2021] [Accepted: 11/19/2021] [Indexed: 11/18/2022] Open
Abstract
Combinations of monoclonal antibodies (mAbs) against different epitopes on the same antigen synergistically neutralize many viruses. However, there are limited studies assessing whether combining human mAbs against distinct regions of the Plasmodium falciparum (Pf) circumsporozoite protein (CSP) enhances in vivo protection against malaria compared to each mAb alone or whether passive transfer of PfCSP mAbs would improve protection following vaccination against PfCSP. Here, we isolated a panel of human mAbs against the subdominant C-terminal domain of PfCSP (C-CSP) from a volunteer immunized with radiation-attenuated Pf sporozoites. These C-CSP-specific mAbs had limited binding to sporozoites in vitro that was increased by combination with neutralizing human “repeat” mAbs against the NPDP/NVDP/NANP tetrapeptides in the central repeat region of PfCSP. Nevertheless, passive transfer of repeat- and C-CSP-specific mAb combinations did not provide enhanced protection against in vivo sporozoite challenge compared to repeat mAbs alone. Furthermore, combining potent repeat-specific mAbs (CIS43, L9, and 317) that respectively target the three tetrapeptides (NPDP/NVDP/NANP) did not provide additional protection against in vivo sporozoite challenge. However, administration of either CIS43, L9, or 317 (but not C-CSP-specific mAbs) to mice that had been immunized with R21, a PfCSP-based virus-like particle vaccine that induces polyclonal antibodies against the repeat region and C-CSP, provided enhanced protection against sporozoite challenge when compared to vaccine or mAbs alone. Collectively, this study shows that while combining mAbs against the repeat and C-terminal regions of PfCSP provide no additional protection in vivo, repeat mAbs do provide increased protection when combined with vaccine-induced polyclonal antibodies. These data should inform the implementation of PfCSP human mAbs alone or following vaccination to prevent malaria infection. The Plasmodium falciparum (Pf) circumsporozoite protein (CSP) is the major surface protein on sporozoites and is required for these malaria parasites to invade the liver. Antibodies can prevent malaria by neutralizing sporozoites prior to liver invasion. The only approved malaria vaccine (RTS,S) is comprised of the repeat region and C-terminus of PfCSP. RTS,S-mediated protection is associated with vaccine-induced antibodies against both regions. While monoclonal antibodies (mAbs) against the three tetrapeptides in the repeat region potently bind and neutralize sporozoites, mAbs against the C-terminus demonstrate limited sporozoite binding and neutralization. Here, we used flow cytometry to show that the sporozoite binding of C-terminal mAbs are potentiated by combining them with repeat mAbs. This in vitro synergy did not translate into enhanced in vivo protection against sporozoite challenge in mice treated with repeat and C-terminal mAb combinations. Furthermore, combining mAbs against the three tetrapeptides in the repeat region did not provide enhanced protection against sporozoite challenge compared to each mAb alone. However, combining passive and active immunization with repeat mAbs and a RTS,S-like vaccine improved protection against sporozoite challenge compared to each intervention alone. These results have important implications for implementing anti-PfCSP mAbs alone or in combination with vaccines to prevent malaria.
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Affiliation(s)
- Lawrence T. Wang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Lais S. Pereira
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Patience K. Kiyuka
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Biological Sciences, Pwani University, Kilifi, Kenya
| | - Arne Schön
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Neville K. Kisalu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Rachel Vistein
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Marlon Dillon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Brian G. Bonilla
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Alvaro Molina-Cruz
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Carolina Barillas-Mury
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Joshua Tan
- Antibody Biology Unit, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Azza H. Idris
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, United States of America
| | - Joseph R. Francica
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Robert A. Seder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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20
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Kurtovic L, Drew DR, Dent AE, Kazura JW, Beeson JG. Antibody Targets and Properties for Complement-Fixation Against the Circumsporozoite Protein in Malaria Immunity. Front Immunol 2021; 12:775659. [PMID: 34925347 PMCID: PMC8671933 DOI: 10.3389/fimmu.2021.775659] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/15/2021] [Indexed: 01/02/2023] Open
Abstract
The Plasmodium falciparum circumsporozoite protein (CSP) forms the basis of leading subunit malaria vaccine candidates. However, the mechanisms and specific targets of immunity are poorly defined. Recent findings suggest that antibody-mediated complement-fixation and activation play an important role in immunity. Here, we investigated the regions of CSP targeted by functional complement-fixing antibodies and the antibody properties associated with this activity. We quantified IgG, IgM, and functional complement-fixing antibody responses to different regions of CSP among Kenyan adults naturally exposed to malaria (n=102) and using a series of rabbit vaccination studies. Individuals who acquired functional complement-fixing antibodies had higher IgG, IgM and IgG1 and IgG3 to CSP. Acquired complement-fixing antibodies targeted the N-terminal, central-repeat, and C-terminal regions of CSP, and positive responders had greater antibody breadth compared to those who were negative for complement-fixing antibodies (p<0.05). Using rabbit vaccinations as a model, we confirmed that IgG specific to the central-repeat and non-repeat regions of CSP could effectively fix complement. However, vaccination with near full length CSP in rabbits poorly induced antibodies to the N-terminal region compared to naturally-acquired immunity in humans. Poor induction of N-terminal antibodies was also observed in a vaccination study performed in mice. IgG and IgM to all three regions of CSP play a role in mediating complement-fixation, which has important implications for malaria vaccine development.
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Affiliation(s)
- Liriye Kurtovic
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Department of Immunology and Pathology, Monash University, Melbourne, VIC, Australia
| | - Damien R. Drew
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
| | - Arlene E. Dent
- Center for Global Health and Diseases, Case Western University, Cleveland, OH, United States
| | - James W. Kazura
- Center for Global Health and Diseases, Case Western University, Cleveland, OH, United States
| | - James G. Beeson
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Department of Immunology and Pathology, Monash University, Melbourne, VIC, Australia
- Department of Microbiology, Monash University, Clayton, VIC, Australia
- Department of Medicine, The University of Melbourne, Parkville, VIC, Australia
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21
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Preclinical development of a Pfs230-Pfs48/45 chimeric malaria transmission-blocking vaccine. NPJ Vaccines 2021; 6:120. [PMID: 34642303 PMCID: PMC8511065 DOI: 10.1038/s41541-021-00383-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 09/17/2021] [Indexed: 11/09/2022] Open
Abstract
The Plasmodium falciparum Pfs230 and Pfs48/45 proteins are leading candidates for a malaria transmission-blocking vaccine (TBV). Previously, we showed that a Pfs230–Pfs48/45 fusion protein elicits higher levels of functional antibodies than the individual antigens, but low yields hampered progression to clinical evaluation. Here we identified a modified construct (ProC6C) with a circumsporozoite protein (CSP) repeat-linker sequence that enhances expression. A scalable and reproducible process in the Lactococcus lactis expression system was developed and ProC6C was successfully transferred for manufacturing under current Good Manufacturing Practices (cGMP). In addition, a panel of analytical assays for release and stability were developed. Intact mass spectrometry analysis and multiangle light scattering showed that the protein contained correct disulfide bonds and was monomeric. Immunogenicity studies in mice showed that the ProC6C adsorbed to Alhydrogel®, with or without Matrix-MTM, elicited functional antibodies that reduced transmission to mosquitoes and sporozoite invasion of human hepatocytes. Altogether, our data support manufacture and clinical evaluation of ProC6C as a multistage malaria-vaccine candidate.
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22
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Reeder SM, Bah MA, Tursi NJ, Brooks RC, Patel A, Esquivel R, Eaton A, Jhun H, Chu J, Kim K, Xu Z, Zavala F, Weiner DB. Strategic Variants of CSP Delivered as SynDNA Vaccines Demonstrate Heterogeneity of Immunogenicity and Protection from Plasmodium Infection in a Murine Model. Infect Immun 2021; 89:e0072820. [PMID: 34152830 PMCID: PMC8445182 DOI: 10.1128/iai.00728-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 05/27/2021] [Indexed: 11/20/2022] Open
Abstract
Malaria infects millions of people every year, and despite recent advances in controlling disease spread, such as vaccination, it remains a global health concern. The circumsporozoite protein (CSP) has long been acknowledged as a key target in antimalarial immunity. Leveraging the DNA vaccine platform against this formidable pathogen, the following five synthetic DNA vaccines encoding variations of CSP were designed and studied: 3D7, GPI1, ΔGPI, TM, and DD2. Among the single CSP antigen constructs, a range of immunogenicity was observed with ΔGPI generating the most robust immunity. In an intravenous (i.v.) sporozoite challenge, the best protection among vaccinated mice was achieved by ΔGPI, which performed almost as well as the monoclonal antibody 311 (MAb 311) antibody control. Further analyses revealed that ΔGPI develops high-molecular-weight multimers in addition to monomeric CSP. We then compared the immunity generated by ΔGPI versus synDNA mimics for the antimalaria vaccines RTS,S and R21. The anti-CSP antibody responses induced were similar among these three immunogens. T cell responses demonstrated that ΔGPI induced a more focused anti-CSP response. In an infectious mosquito challenge, all three of these constructs generated inhibition of liver-stage infection as well as immunity from blood-stage parasitemia. This study demonstrates that synDNA mimics of complex malaria immunogens can provide substantial protection as can a novel synDNA vaccine ΔGPI.
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Affiliation(s)
- Sophia M. Reeder
- The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Mamadou A. Bah
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Nicholas J. Tursi
- The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Rebekah C. Brooks
- The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Ami Patel
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Rianne Esquivel
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Alison Eaton
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Hugo Jhun
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Jacqueline Chu
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Kevin Kim
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Ziyang Xu
- The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Fidel Zavala
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - David B. Weiner
- The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Vaccine Center, Wistar Institute, Philadelphia, Pennsylvania, USA
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23
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In vitro and in vivo inhibition of malaria parasite infection by monoclonal antibodies against Plasmodium falciparum circumsporozoite protein (CSP). Sci Rep 2021; 11:5318. [PMID: 33674699 PMCID: PMC7970865 DOI: 10.1038/s41598-021-84622-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 02/11/2021] [Indexed: 01/23/2023] Open
Abstract
Plasmodium falciparum malaria contributes to a significant global disease burden. Circumsporozoite protein (CSP), the most abundant sporozoite stage antigen, is a prime vaccine candidate. Inhibitory monoclonal antibodies (mAbs) against CSP map to either a short junctional sequence or the central (NPNA)n repeat region. We compared in vitro and in vivo activities of six CSP-specific mAbs derived from human recipients of a recombinant CSP vaccine RTS,S/AS01 (mAbs 317 and 311); an irradiated whole sporozoite vaccine PfSPZ (mAbs CIS43 and MGG4); or individuals exposed to malaria (mAbs 580 and 663). RTS,S mAb 317 that specifically binds the (NPNA)n epitope, had the highest affinity and it elicited the best sterile protection in mice. The most potent inhibitor of sporozoite invasion in vitro was mAb CIS43 which shows dual-specific binding to the junctional sequence and (NPNA)n. In vivo mouse protection was associated with the mAb reactivity to the NANPx6 peptide, the in vitro inhibition of sporozoite invasion activity, and kinetic parameters measured using intact mAbs or their Fab fragments. Buried surface area between mAb and its target epitope was also associated with in vivo protection. Association and disconnects between in vitro and in vivo readouts has important implications for the design and down-selection of the next generation of CSP based interventions.
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24
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Chatterjee D, Cockburn IA. The challenges of a circumsporozoite protein-based malaria vaccine. Expert Rev Vaccines 2021; 20:113-125. [PMID: 33554669 DOI: 10.1080/14760584.2021.1874924] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION A safe and effective vaccine will likely be necessary for the control or eradication of malaria which kills 400,000 annually. Our most advanced vaccine candidate to date is RTS,S which is based on the Plasmodium falciparum circumsporozoite protein (PfCSP) of the malaria parasite. However, protection by RTS,S is incomplete and short-lived. AREAS COVERED Here we summarize results from recent clinical trials of RTS,S and critically evaluate recent studies that aim to understand the correlates of protective immunity and why vaccine-induced protection is short-lived. In particular, recent systems serology studies have highlighted a key role for the necessity of inducing functional antibodies. In-depth analyses of immune responses to CSP in both mouse models and vaccinated humans have also highlighted difficulties in generating the maintaining high-quality antibody responses. Finally, in recent years biophysical and structural studies of antibody binding to PfCSP have led to a better understanding of how highly potent antibodies can block infection, which can inform vaccine design. EXPERT OPINION We highlight how both structure-guided vaccine design and a better understanding of the immune response to PfCSP can inform a second generation of PfCSP-based vaccines stimulating a broader range of protective targets within PfCSP.
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Affiliation(s)
- Deepyan Chatterjee
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, the Australian National University, Canberra, Australia
| | - Ian Andrew Cockburn
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, the Australian National University, Canberra, Australia
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25
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Brunetti G, Padovani F, De Pastina A, Rotella C, Monahan A, Hoffman SL, Jongo SA, Abdulla S, Corradin G, Pluschke G, Daubenberger C, Hegner M. Nanotechnological immunoassay for rapid label-free analysis of candidate malaria vaccines. NANOSCALE 2021; 13:2338-2349. [PMID: 33438712 DOI: 10.1039/d0nr08083g] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Malaria is a life-threatening epidemic disease with half of the world's population at risk. Although its incidence rate has fallen since 2010, this ratio dramatically stalled between 2014 and 2018. New fast and optimized tools in vaccine analysis and seroconversion testing are critically needed. We developed a clinical diagnostic device based on piezo-actuated nanoresonators that perform as quantitative in situ calibrated nano-bio sensors for specific detection of multiple target molecules in serum samples. The immunoassay successfully diagnoses humoral immune responses induced by malaria vaccine candidates and reveals the timeline and stage of the infection. We applied the newly developed strategy to a variety of different samples, from pure antibody/vaccine solutions, to blood samples from clinical trials on both naïve and pre-exposed malaria volunteers from sub-Saharan countries. Our nanomechanical assay provides a direct one-step label-free quantitative immunoassay that is on par with the gold-standard, multi-step enzyme-linked immunosorbent assay (ELISA). We achieve a limit of detection of few pg ml-1, or sub-pM concentrations. The 6 μl sample volume allows more than 50 experiments from one finger prick. Furthermore, we simultaneously detected multiple analytes by differential functionalization of multiple sensors in parallel. The inherent differential read-out with in situ controls reduces false positive results. Due to the faster turnaround time, the minimal volume required and the automatized handling system, this technique has great potential for miniaturization and routine diagnostics in pandemic emergencies.
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Affiliation(s)
- Giulio Brunetti
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | - Francesco Padovani
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland. and Institute of Functional Epigenetics, Helmholtz Zentrum München (HMGU), Neuherberg 85764, Germany
| | - Annalisa De Pastina
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | - Chiara Rotella
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | - Amy Monahan
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
| | | | - Said A Jongo
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Salim Abdulla
- Bagamoyo Research and Training Centre, Ifakara Health Institute, Bagamoyo, Tanzania
| | | | - Gerd Pluschke
- Medical Parasitology and Infection Biology Department, Molecular Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland and University of Basel, Switzerland
| | - Claudia Daubenberger
- University of Basel, Switzerland and Medical Parasitology and Infection Biology Department, Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland.
| | - Martin Hegner
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), School of Physics, Trinity College Dublin, Dublin, Ireland.
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26
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Schneider CG, Taylor JA, Sibilo MQ, Miura K, Mallory KL, Mann C, Karch C, Beck Z, Matyas GR, Long CA, Bergmann-Leitner E, Burkhard P, Angov E. Orientation of Antigen Display on Self-Assembling Protein Nanoparticles Influences Immunogenicity. Vaccines (Basel) 2021; 9:vaccines9020103. [PMID: 33572803 PMCID: PMC7911071 DOI: 10.3390/vaccines9020103] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 11/16/2022] Open
Abstract
Self-assembling protein nanoparticles (SAPN) serve as a repetitive antigen delivery platform with high-density epitope display; however, antigen characteristics such as size and epitope presentation can influence the immunogenicity of the assembled particle and are aspects to consider for a rationally designed effective vaccine. Here, we characterize the folding and immunogenicity of heterogeneous antigen display by integrating (a) dual-stage antigen SAPN presenting the P. falciparum (Pf) merozoite surface protein 1 subunit, PfMSP119, and Pf cell-traversal protein for ookinetes and sporozoites, PfCelTOS, in addition to (b) a homogenous antigen SAPN displaying two copies of PfCelTOS. Mice and rabbits were utilized to evaluate antigen-specific humoral and cellular induction as well as functional antibodies via growth inhibition of the blood-stage parasite. We demonstrate that antigen orientation and folding influence the elicited immune response, and when appropriately designed, SAPN can serve as an adaptable platform for an effective multi-antigen display.
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Affiliation(s)
- Cosette G. Schneider
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37831, USA
| | - Justin A. Taylor
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37831, USA
| | - Michael Q. Sibilo
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Parsons Corporation, Centreville, VA 20120, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD 20892, USA; (K.M.); (C.A.L.)
| | - Katherine L. Mallory
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Parsons Corporation, Centreville, VA 20120, USA
| | - Christopher Mann
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Parsons Corporation, Centreville, VA 20120, USA
| | - Christopher Karch
- Laboratory of Antigen and Adjuvants, US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.K.); (Z.B.); (G.R.M.)
- Henry Jackson Foundation, Bethesda, MD 20817, USA
| | - Zoltan Beck
- Laboratory of Antigen and Adjuvants, US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.K.); (Z.B.); (G.R.M.)
- Henry Jackson Foundation, Bethesda, MD 20817, USA
| | - Gary R. Matyas
- Laboratory of Antigen and Adjuvants, US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.K.); (Z.B.); (G.R.M.)
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD 20892, USA; (K.M.); (C.A.L.)
| | - Elke Bergmann-Leitner
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
| | | | - Evelina Angov
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (C.G.S.); (J.A.T.); (M.Q.S.); (K.L.M.); (C.M.); (E.B.-L.)
- Correspondence: ; Tel.: +1-301-319-9614
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27
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Mahamar A, Issiaka D, Youssouf A, Niambele SM, Soumare HM, Attaher O, Barry A, Narum DL, Duffy PE, Greenwood B, Fried M, Dicko A. Effect of 4 years of seasonal malaria chemoprevention on the acquisition of antibodies to Plasmodium falciparum antigens in Ouelessebougou, Mali. Malar J 2021; 20:23. [PMID: 33413417 PMCID: PMC7788529 DOI: 10.1186/s12936-020-03542-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/10/2020] [Indexed: 12/01/2022] Open
Abstract
Background More than 200 million people live in areas of highly seasonal malaria transmission where Seasonal Malaria Chemoprevention (SMC) with sulfadoxine-pyrimethamine (SP) and amodiaquine (AQ) was recommended in 2012 by WHO. This strategy is now implemented widely and protected more than 19 million children in 2018. It was previously reported that exposure to SMC reduced antibody levels to AMA1, MSP-142 and CSP, but the duration of exposure to SMC up to three 3 years, had no effect on antibody levels to MSP-142 and CSP. Methods In 2017, a cross-sectional survey was carried out 1 month after the last dose of SMC had been given to children aged 4–5 years randomly selected from areas where SMC had been given for 2 or 4 years during the malaria transmission season. A total of 461 children were enrolled, 242 children in areas where SMC had been implemented for 4 years and 219 children in areas where SMC had been implemented for 2 years. Antibody extracted from dry blood spots was used to measure IgG levels to the malaria antigens CSP, MSP-142 and AMA1 by ELISA. Results The prevalence of antibodies to MSP-142 was similar in children who had received SMC for 4 years compared to those who had received SMC for only 2 years (85.1 vs 86.0%, ajusted odd ratio (aOR) = 1.06, 95% confidence intervals (CI 0.62–1.80), p = 0.80). The prevalence of antibodies to AMA-1 and to CSP was not lower in children who received SMC for 4 years compared to those who had received SMC for only 2 years (95.3 vs 88.8%, aOR = 3.16, 95% CI 1.44–6.95, p = 0.004 for AMA-1; and 91.2 vs 81.9%, aOR = 3.14, 95% CI 1.70–5.76, p < 0.001 for CSP). Median antibody levels for anti-MSP-142 IgG were not significatively inferior in children who had received SMC for four rather than 2 years (0.88 (IQR: 0.64–1.15) and 0.95 ((0.68–1.15), respectively), anti-CSP (1.30 (1.00–1.56) and 1.17 (0.87–1.47)), and anti-AMA-1 (1.45 (1.24–1.68) and 1.41 (1.17–1.64)). Conclusion In an area of high seasonal malaria transmission, children who had received SMC for 4 years did not had lower seropositivity or antibody levels to AMA1, MSP-142 and CSP compared to children who had received SMC for only 2 years suggesting that children who have received SMC for 4 years may not be more at risk of malaria after the cessation of SMC than children who have received SMC for a shorter period.
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Affiliation(s)
- Almahamoudou Mahamar
- Mali Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Science, Techniques and Technologies (USTT), Bamako, Mali
| | - Djibrilla Issiaka
- Mali Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Science, Techniques and Technologies (USTT), Bamako, Mali
| | - Ahamadou Youssouf
- Mali Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Science, Techniques and Technologies (USTT), Bamako, Mali
| | - Sidi M Niambele
- Mali Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Science, Techniques and Technologies (USTT), Bamako, Mali
| | - Harouna M Soumare
- Mali Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Science, Techniques and Technologies (USTT), Bamako, Mali
| | - Oumar Attaher
- Mali Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Science, Techniques and Technologies (USTT), Bamako, Mali
| | - Amadou Barry
- Mali Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Science, Techniques and Technologies (USTT), Bamako, Mali
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology (LMIV), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Rockville, MD, USA
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology (LMIV), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Rockville, MD, USA
| | - Brian Greenwood
- London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology (LMIV), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Rockville, MD, USA
| | - Alassane Dicko
- Mali Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Science, Techniques and Technologies (USTT), Bamako, Mali.
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Kucharska I, Thai E, Srivastava A, Rubinstein JL, Pomès R, Julien JP. Structural ordering of the Plasmodium berghei circumsporozoite protein repeats by inhibitory antibody 3D11. eLife 2020; 9:e59018. [PMID: 33253113 PMCID: PMC7704109 DOI: 10.7554/elife.59018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 11/04/2020] [Indexed: 12/15/2022] Open
Abstract
Plasmodium sporozoites express circumsporozoite protein (CSP) on their surface, an essential protein that contains central repeating motifs. Antibodies targeting this region can neutralize infection, and the partial efficacy of RTS,S/AS01 - the leading malaria vaccine against P. falciparum (Pf) - has been associated with the humoral response against the repeats. Although structural details of antibody recognition of PfCSP have recently emerged, the molecular basis of antibody-mediated inhibition of other Plasmodium species via CSP binding remains unclear. Here, we analyze the structure and molecular interactions of potent monoclonal antibody (mAb) 3D11 binding to P. berghei CSP (PbCSP) using molecular dynamics simulations, X-ray crystallography, and cryoEM. We reveal that mAb 3D11 can accommodate all subtle variances of the PbCSP repeating motifs, and, upon binding, induces structural ordering of PbCSP through homotypic interactions. Together, our findings uncover common mechanisms of antibody evolution in mammals against the CSP repeats of Plasmodium sporozoites.
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Affiliation(s)
- Iga Kucharska
- Program in Molecular Medicine, The Hospital for Sick Children Research InstituteTorontoCanada
| | - Elaine Thai
- Program in Molecular Medicine, The Hospital for Sick Children Research InstituteTorontoCanada
- Department of Biochemistry, University of TorontoTorontoCanada
| | - Ananya Srivastava
- Program in Molecular Medicine, The Hospital for Sick Children Research InstituteTorontoCanada
- Department of Biochemistry, University of TorontoTorontoCanada
| | - John L Rubinstein
- Program in Molecular Medicine, The Hospital for Sick Children Research InstituteTorontoCanada
- Department of Biochemistry, University of TorontoTorontoCanada
- Department of Medical Biophysics, University of TorontoTorontoCanada
| | - Régis Pomès
- Program in Molecular Medicine, The Hospital for Sick Children Research InstituteTorontoCanada
- Department of Biochemistry, University of TorontoTorontoCanada
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research InstituteTorontoCanada
- Department of Biochemistry, University of TorontoTorontoCanada
- Department of Immunology, University of TorontoTorontoCanada
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29
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A Potent Anti-Malarial Human Monoclonal Antibody Targets Circumsporozoite Protein Minor Repeats and Neutralizes Sporozoites in the Liver. Immunity 2020; 53:733-744.e8. [PMID: 32946741 DOI: 10.1016/j.immuni.2020.08.014] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/10/2020] [Accepted: 08/24/2020] [Indexed: 01/05/2023]
Abstract
Discovering potent human monoclonal antibodies (mAbs) targeting the Plasmodium falciparum circumsporozoite protein (PfCSP) on sporozoites (SPZ) and elucidating their mechanisms of neutralization will facilitate translation for passive prophylaxis and aid next-generation vaccine development. Here, we isolated a neutralizing human mAb, L9 that preferentially bound NVDP minor repeats of PfCSP with high affinity while cross-reacting with NANP major repeats. L9 was more potent than six published neutralizing human PfCSP mAbs at mediating protection against mosquito bite challenge in mice. Isothermal titration calorimetry and multiphoton microscopy showed that L9 and the other most protective mAbs bound PfCSP with two binding events and mediated protection by killing SPZ in the liver and by preventing their egress from sinusoids and traversal of hepatocytes. This study defines the subdominant PfCSP minor repeats as neutralizing epitopes, identifies an in vitro biophysical correlate of SPZ neutralization, and demonstrates that the liver is an important site for antibodies to prevent malaria.
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30
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Singh K, Burkhardt M, Nakuchima S, Herrera R, Muratova O, Gittis AG, Kelnhofer E, Reiter K, Smelkinson M, Veltri D, Swihart BJ, Shimp R, Nguyen V, Zhang B, MacDonald NJ, Duffy PE, Garboczi DN, Narum DL. Structure and function of a malaria transmission blocking vaccine targeting Pfs230 and Pfs230-Pfs48/45 proteins. Commun Biol 2020; 3:395. [PMID: 32709983 PMCID: PMC7381611 DOI: 10.1038/s42003-020-01123-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 07/03/2020] [Indexed: 12/21/2022] Open
Abstract
Proteins Pfs230 and Pfs48/45 are Plasmodium falciparum transmission-blocking (TB) vaccine candidates that form a membrane-bound protein complex on gametes. The biological role of Pfs230 or the Pfs230-Pfs48/45 complex remains poorly understood. Here, we present the crystal structure of recombinant Pfs230 domain 1 (Pfs230D1M), a 6-cysteine domain, in complex with the Fab fragment of a TB monoclonal antibody (mAb) 4F12. We observed the arrangement of Pfs230 on the surface of macrogametes differed from that on microgametes, and that Pfs230, with no known membrane anchor, may exist on the membrane surface in the absence of Pfs48/45. 4F12 appears to sterically interfere with Pfs230 function. Combining mAbs against different epitopes of Pfs230D1 or of Pfs230D1 and Pfs48/45, significantly increased TB activity. These studies elucidate a mechanism of action of the Pfs230D1 vaccine, model the functional activity induced by a polyclonal antibody response and support the development of TB vaccines targeting Pfs230D1 and Pfs230D1-Pfs48/45. With the aim to advance the development of a P. falciparum transmission blocking vaccine, Singh et al. determine the crystal structure of Pfs230D1 in complex with the Fab fragment of TB mAb 4F12. They further study the cellular localization of Pfs230 on the surface of sexual stages of parasites and the effect of combining TB mAbs against Pfs230 and Pfs48/45.
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Affiliation(s)
- Kavita Singh
- Structural Biology Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Martin Burkhardt
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Sofia Nakuchima
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Raul Herrera
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Olga Muratova
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Apostolos G Gittis
- Structural Biology Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Emily Kelnhofer
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Karine Reiter
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Margery Smelkinson
- Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 4 Memorial Drive, Bethesda, MD, 20814, USA
| | - Daniel Veltri
- Bioinformatics and Computational Biosciences Branch, Office of Cyber Infrastructure and Computational Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 5601 Fishers Lane, Rockville, MD, 20852, USA
| | - Bruce J Swihart
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 5601 Fishers Lane, Rockville, MD, 20852, USA
| | - Richard Shimp
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Vu Nguyen
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Baoshan Zhang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20814, USA
| | - Nicholas J MacDonald
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - David N Garboczi
- Structural Biology Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 29 Lincoln Drive, Bethesda, MD, 20892, USA.
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31
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Huang HY, Liang XY, Lin LY, Chen JT, Ehapo CS, Eyi UM, Li J, Jiang TT, Zheng YZ, Zha GC, Xie DD, He JQ, Chen WZ, Liu XZ, Mo HT, Chen XY, Lin M. Genetic polymorphism of Plasmodium falciparum circumsporozoite protein on Bioko Island, Equatorial Guinea and global comparative analysis. Malar J 2020; 19:245. [PMID: 32660484 PMCID: PMC7359586 DOI: 10.1186/s12936-020-03315-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 07/04/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Plasmodium falciparum circumsporozoite protein (PfCSP) is a potential malaria vaccine candidate, but various polymorphisms of the pfcsp gene among global P. falciparum population become the major barrier to the effectiveness of vaccines. This study aimed to investigate the genetic polymorphisms and natural selection of pfcsp in Bioko and the comparison among global P. falciparum population. METHODS From January 2011 to December 2018, 148 blood samples were collected from P. falciparum infected Bioko patients and 96 monoclonal sequences of them were successfully acquired and analysed with 2200 global pfcsp sequences mined from MalariaGEN Pf3k Database and NCBI. RESULTS In Bioko, the N-terminus of pfcsp showed limited genetic variations and the numbers of repetitive sequences (NANP/NVDP) were mainly found as 40 (35%) and 41 (34%) in central region. Most polymorphic characters were found in Th2R/Th3R region, where natural selection (p > 0.05) and recombination occurred. The overall pattern of Bioko pfcsp gene had no obvious deviation from African mainland pfcsp (Fst = 0.00878, p < 0.05). The comparative analysis of Bioko and global pfcsp displayed the various mutation patterns and obvious geographic differentiation among populations from four continents (p < 0.05). The global pfcsp C-terminal sequences were clustered into 138 different haplotypes (H_1 to H_138). Only 3.35% of sequences matched 3D7 strain haplotype (H_1). CONCLUSIONS The genetic polymorphism phenomena of pfcsp were found universal in Bioko and global isolates and the majority mutations located at T cell epitopes. Global genetic polymorphism and geographical characteristics were recommended to be considered for future improvement of malaria vaccine design.
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Affiliation(s)
- Hui-Ying Huang
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, People's Republic of China
- Department of Medical Genetics, Shantou University Medical College, Shantou, Guangdong Province, People's Republic of China
| | - Xue-Yan Liang
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, People's Republic of China
- Department of Medical Genetics, Shantou University Medical College, Shantou, Guangdong Province, People's Republic of China
| | - Li-Yun Lin
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, People's Republic of China
| | - Jiang-Tao Chen
- Department of Medical Laboratory, Huizhou Central Hospital, Huizhou, Guangdong Province, People's Republic of China
- The Chinese Medical Aid Team to the Republic of Equatorial Guinea, Guangzhou, Guangdong Province, People's Republic of China
| | - Carlos Salas Ehapo
- Department of Medical Laboratory, Malabo Regional Hospital, Malabo, Equatorial Guinea
| | - Urbano Monsuy Eyi
- Department of Medical Laboratory, Malabo Regional Hospital, Malabo, Equatorial Guinea
| | - Jian Li
- Department of Human Parasitology, School of Basic Medical Sciences, Department of Infectious Diseases, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei Province, People's Republic of China
| | - Ting-Ting Jiang
- Department of Human Parasitology, School of Basic Medical Sciences, Department of Infectious Diseases, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei Province, People's Republic of China
| | - Yu-Zhong Zheng
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, People's Republic of China
| | - Guang-Cai Zha
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, People's Republic of China
| | - Dong-De Xie
- The Chinese Medical Aid Team to the Republic of Equatorial Guinea, Guangzhou, Guangdong Province, People's Republic of China
| | - Jin-Quan He
- The Chinese Medical Aid Team to the Republic of Equatorial Guinea, Guangzhou, Guangdong Province, People's Republic of China
| | - Wei-Zhong Chen
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China
| | - Xiang-Zhi Liu
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China
| | - Huan-Tong Mo
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China
| | - Xin-Yao Chen
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China
| | - Min Lin
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, People's Republic of China.
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou, Guangdong Province, People's Republic of China.
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Obeng-Adjei N, Larremore DB, Turner L, Ongoiba A, Li S, Doumbo S, Yazew TB, Kayentao K, Miller LH, Traore B, Pierce SK, Buckee CO, Lavstsen T, Crompton PD, Tran TM. Longitudinal analysis of naturally acquired PfEMP1 CIDR domain variant antibodies identifies associations with malaria protection. JCI Insight 2020; 5:137262. [PMID: 32427581 DOI: 10.1172/jci.insight.137262] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 05/06/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUNDMalaria pathogenicity is determined, in part, by the adherence of Plasmodium falciparum-infected erythrocytes to the microvasculature mediated via specific interactions between P. falciparum erythrocyte membrane protein (PfEMP1) variant domains and host endothelial receptors. Naturally acquired antibodies against specific PfEMP1 variants can play an important role in clinical protection against malaria.METHODSWe evaluated IgG responses against a repertoire of PfEMP1 CIDR domain variants to determine the rate and order of variant-specific antibody acquisition and their association with protection against febrile malaria in a prospective cohort study conducted in an area of intense, seasonal malaria transmission.RESULTSUsing longitudinal data, we found that IgG antibodies against the pathogenic domain variants CIDRα1.7 and CIDRα1.8 were acquired the earliest. Furthermore, IgG antibodies against CIDRγ3 were associated with reduced prospective risk of febrile malaria and recurrent malaria episodes.CONCLUSIONThis study provides evidence that acquisition of IgG antibodies against PfEMP1 variants is ordered and demonstrates that antibodies against CIDRα1 domains are acquired the earliest in children residing in an area of intense, seasonal malaria transmission. Future studies will need to validate these findings in other transmission settings and determine the functional activity of these naturally acquired CIDR variant-specific antibodies.TRIAL REGISTRATIONClinicalTrials.gov NCT01322581.FUNDINGDivision of Intramural Research, National Institute of Allergy and Infectious Diseases, NIH.
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Affiliation(s)
- Nyamekye Obeng-Adjei
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA.,Innate Immunity Research Unit, GlaxoSmithKline, Collegeville, Pennsylvania, USA
| | - Daniel B Larremore
- Department of Computer Science and.,BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, USA
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Aissata Ongoiba
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | - Shanping Li
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA
| | - Safiatou Doumbo
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | | | - Kassoum Kayentao
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, Maryland, USA
| | - Boubacar Traore
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, Bamako, Mali
| | | | - Caroline O Buckee
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Peter D Crompton
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA
| | - Tuan M Tran
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA.,Division of Infectious Diseases, Department of Medicine, and.,Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA
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33
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Oyen D, Torres JL, Aoto PC, Flores-Garcia Y, Binter Š, Pholcharee T, Carroll S, Reponen S, Wash R, Liang Q, Lemiale F, Locke E, Bradley A, King CR, Emerling D, Kellam P, Zavala F, Ward AB, Wilson IA. Structure and mechanism of monoclonal antibody binding to the junctional epitope of Plasmodium falciparum circumsporozoite protein. PLoS Pathog 2020; 16:e1008373. [PMID: 32150583 PMCID: PMC7082059 DOI: 10.1371/journal.ppat.1008373] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 03/19/2020] [Accepted: 01/31/2020] [Indexed: 11/21/2022] Open
Abstract
Lasting protection has long been a goal for malaria vaccines. The major surface antigen on Plasmodium falciparum sporozoites, the circumsporozoite protein (PfCSP), has been an attractive target for vaccine development and most protective antibodies studied to date interact with the central NANP repeat region of PfCSP. However, it remains unclear what structural and functional characteristics correlate with better protection by one antibody over another. Binding to the junctional region between the N-terminal domain and central NANP repeats has been proposed to result in superior protection: this region initiates with the only NPDP sequence followed immediately by NANP. Here, we isolated antibodies in Kymab mice immunized with full-length recombinant PfCSP and two protective antibodies were selected for further study with reactivity against the junctional region. X-ray and EM structures of two monoclonal antibodies, mAb667 and mAb668, shed light on their differential affinity and specificity for the junctional region. Importantly, these antibodies also bind to the NANP repeat region with equal or better affinity. A comparison with an NANP-only binding antibody (mAb317) revealed roughly similar but statistically distinct levels of protection against sporozoite challenge in mouse liver burden models, suggesting that junctional antibody protection might relate to the ability to also cross-react with the NANP repeat region. Our findings indicate that additional efforts are necessary to isolate a true junctional antibody with no or much reduced affinity to the NANP region to elucidate the role of the junctional epitope in protection. The circumsporozoite protein (CSP) of Plasmodium falciparum malaria has been the foundation for the design of transmission blocking malaria vaccines. To date, the most promising CSP-based vaccine candidate is RTS,S, which consists of the central repeating NANP amino-acid sequence and the C-terminal domain of CSP fused to hepatitis B surface antigen that assembles into virus-like particles. Potential shortcomings of RTS,S includes the lack of other potential CSP epitopes such as the junctional epitope, which is located between the N-terminal domain of CSP and the start of the NANP repeat region. Here, we elicited antibodies against full-length CSP and screened for junctional epitope binding. We then used an array of biophysical techniques to elucidate the nature of the binding and tested the level of two protective antibodies in a mouse challenge model. Although the antibodies were able to bind both junctional and NANP epitopes, the in vivo data showed distinct levels of protection between themselves and also to an NANP-only binder. Our data suggest that their protection ability may be related to the strong cross-reactivity with NANP epitopes. Since all reported junctional antibodies to date have dual-specificity, we suggest that a true junctional binder with no or very low NANP affinity, if one can be found, is essential to evaluate the contribution of the junctional epitope to protection.
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Affiliation(s)
- David Oyen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Jonathan L. Torres
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Phillip C. Aoto
- Department of Pharmacology, University of California at San Diego, La Jolla, California, United States of America
| | - Yevel Flores-Garcia
- Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Špela Binter
- Kymab Ltd., The Bennet Building (B930), Babraham Research Campus, Cambridge, United Kingdom
| | - Tossapol Pholcharee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Sean Carroll
- Atreca Inc., South San Francisco, California, United States of America
| | - Sini Reponen
- Atreca Inc., South San Francisco, California, United States of America
| | - Rachael Wash
- Kymab Ltd., The Bennet Building (B930), Babraham Research Campus, Cambridge, United Kingdom
| | - Qi Liang
- Kymab Ltd., The Bennet Building (B930), Babraham Research Campus, Cambridge, United Kingdom
| | - Franck Lemiale
- PATH’s Malaria Vaccine Initiative, PATH Center for Vaccine Innovation and Access, Washington, United States of America
| | - Emily Locke
- PATH’s Malaria Vaccine Initiative, PATH Center for Vaccine Innovation and Access, Washington, United States of America
| | - Allan Bradley
- Kymab Ltd., The Bennet Building (B930), Babraham Research Campus, Cambridge, United Kingdom
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - C. Richter King
- PATH’s Malaria Vaccine Initiative, PATH Center for Vaccine Innovation and Access, Washington, United States of America
| | - Daniel Emerling
- Atreca Inc., South San Francisco, California, United States of America
| | - Paul Kellam
- Kymab Ltd., The Bennet Building (B930), Babraham Research Campus, Cambridge, United Kingdom
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Fidel Zavala
- Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Andrew B. Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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Design and assessment of TRAP-CSP fusion antigens as effective malaria vaccines. PLoS One 2020; 15:e0216260. [PMID: 31967991 PMCID: PMC6975556 DOI: 10.1371/journal.pone.0216260] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 12/16/2019] [Indexed: 11/25/2022] Open
Abstract
The circumsporozoite protein (CSP) and thrombospondin-related adhesion protein (TRAP) are major targets for pre-erythrocytic malaria vaccine development. However, the CSP-based vaccine RTS,S provides only marginal protection, highlighting the need for innovative vaccine design and development. Here we design and characterize expression and folding of P. berghei (Pb) and P. falciparum (Pf) TRAP-CSP fusion proteins, and evaluate immunogenicity and sterilizing immunity in mice. TRAP N-terminal domains were fused to the CSP C-terminal αTSR domain with or without the CSP repeat region, expressed in mammalian cells, and evaluated with or without N-glycan shaving. Pb and Pf fusions were each expressed substantially better than the TRAP or CSP components alone; furthermore, the fusions but not the CSP component could be purified to homogeneity and were well folded and monomeric. As yields of TRAP and CSP fragments were insufficient, we immunized BALB/c mice with Pb TRAP-CSP fusions in AddaVax adjuvant and tested the effects of absence or presence of the CSP repeats and absence or presence of high mannose N-glycans on total antibody titer and protection from infection by mosquito bite both 2.5 months and 6 months after the last immunization. Fusions containing the repeats were completely protective against challenge and re-challenge, while those lacking repeats were significantly less effective. These results correlated with higher total antibody titers when repeats were present. Our results show that TRAP-CSP fusions increase protein antigen production, have the potential to yield effective vaccines, and also guide design of effective proteins that can be encoded by nucleic acid-based and virally vectored vaccines.
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Singh SK, Plieskatt J, Chourasia BK, Singh V, Bolscher JM, Dechering KJ, Adu B, López-Méndez B, Kaviraj S, Locke E, King CR, Theisen M. The Plasmodium falciparum circumsporozoite protein produced in Lactococcus lactis is pure and stable. J Biol Chem 2019; 295:403-414. [PMID: 31792057 DOI: 10.1074/jbc.ra119.011268] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/03/2019] [Indexed: 12/20/2022] Open
Abstract
The Plasmodium falciparum circumsporozoite protein (PfCSP) is a sporozoite surface protein whose role in sporozoite motility and cell invasion has made it the leading candidate for a pre-erythrocytic malaria vaccine. However, production of high yields of soluble recombinant PfCSP, including its extensive NANP and NVDP repeats, has proven problematic. Here, we report on the development and characterization of a secreted, soluble, and stable full-length PfCSP (containing 4 NVDP and 38 NANP repeats) produced in the Lactococcus lactis expression system. The recombinant full-length PfCSP, denoted PfCSP4/38, was produced initially with a histidine tag and purified by a simple two-step procedure. Importantly, the recombinant PfCSP4/38 retained a conformational epitope for antibodies as confirmed by both in vivo and in vitro characterizations. We characterized this complex protein by HPLC, light scattering, MS analysis, differential scanning fluorimetry, CD, SDS-PAGE, and immunoblotting with conformation-dependent and -independent mAbs, which confirmed it to be both pure and soluble. Moreover, we found that the recombinant protein is stable at both frozen and elevated-temperature storage conditions. When we used L. lactis-derived PfCSP4/38 to immunize mice, it elicited high levels of functional antibodies that had the capacity to modify sporozoite motility in vitro We concluded that the reported yield, purity, results of biophysical analyses, and stability of PfCSP4/38 warrant further consideration of using the L. lactis system for the production of circumsporozoite proteins for preclinical and clinical applications in malaria vaccine development.
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Affiliation(s)
- Susheel K Singh
- Department for Congenital Disorders, Statens Serum Institut, 2300 Copenhagen, Denmark; Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark
| | | | - Bishwanath Kumar Chourasia
- Department for Congenital Disorders, Statens Serum Institut, 2300 Copenhagen, Denmark; Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Vandana Singh
- Department for Congenital Disorders, Statens Serum Institut, 2300 Copenhagen, Denmark; Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark
| | | | | | - Bright Adu
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Blanca López-Méndez
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | - Emily Locke
- PATH's Malaria Vaccine Initiative, Washington, D. C. 20001
| | - C Richter King
- PATH's Malaria Vaccine Initiative, Washington, D. C. 20001
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, 2300 Copenhagen, Denmark; Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark.
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Zhan X, Yu L, An X, Liu Q, Li M, Nie Z, Zhao Y, Wang S, Ao Y, Tian Y, He L, Zhao J. Evaluation of Babesia gibsoni GPI-anchored Protein 47 (BgGPI47-WH) as a Potential Diagnostic Antigen by Enzyme-Linked Immunosorbent Assay. Front Vet Sci 2019; 6:333. [PMID: 31681802 PMCID: PMC6797833 DOI: 10.3389/fvets.2019.00333] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/16/2019] [Indexed: 11/13/2022] Open
Abstract
Babesia gibsoni is one of the important pathogens causing severe incurable canine babesiosis, suggesting the necessity to develop a sensitive, specific, and highly automated diagnostic method for clinical application. Surface proteins are ideal candidates for diagnostic targets because they are the primary targets for host immune responses during host-parasite interactions. Glycosylphosphatidylinositol (GPI)-anchored proteins are abundant on the surface of parasites and play an important role in parasite diagnosis. In this study, a GPI-anchored protein named BgGPI47-WH was obtained and mouse anti-rBgGPI47-WH polyclonal antibody was produced by immunizing mice with the purified protein and Freund's adjuvant. Western blot was used to identify the native form and immunogenicity of BgGPI47-WH. An ELISA method was established by using recombinant BgGPI47-WH protein to evaluate its potential as a diagnostic antigen and the established method exhibited high specificity. The antibody response was evaluated by using the B. gibsoni-infected sera collected from different experimental dogs and the established ELISA could recognize antibodies at day 6 until day 101 post infection, indicating the potential use of BgGPI47-WH for early stage diagnosis. The specificity of the established ELISA was further evaluated by using 147 clinical samples collected from animal hospitals and 17.0% (25/147) of the samples were tested positive, with an overall proportion agreement of 86.39% between the results from BgGPI47-WH and BgSA1. Our results indicated that BgGPI47-WH could be used as a reliable diagnostic antigen and this study has proposed a practical method for early diagnosis of B. gibsoni.
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Affiliation(s)
- Xueyan Zhan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Long Yu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Xiaomeng An
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Qin Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Muxiao Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Zheng Nie
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yangnan Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China
| | - Sen Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yangsiqi Ao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yu Tian
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Lan He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
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Mohamed NS, Ali Albsheer MM, Abdelbagi H, Siddig EE, Mohamed MA, Ahmed AE, Omer RA, Muneer MS, Ahmed A, Osman HA, Ali MS, Eisa IM, Elbasheir MM. Genetic polymorphism of the N-terminal region in circumsporozoite surface protein of Plasmodium falciparum field isolates from Sudan. Malar J 2019; 18:333. [PMID: 31570093 PMCID: PMC6771110 DOI: 10.1186/s12936-019-2970-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 09/24/2019] [Indexed: 11/28/2022] Open
Abstract
Background Malaria caused by Plasmodium falciparum parasite is still known to be one of the most significant public health problems in sub-Saharan Africa. Genetic diversity of the Sudanese P. falciparum based on the diversity in the circumsporozoite surface protein (PfCSP) has not been previously studied. Therefore, this study aimed to investigate the genetic diversity of the N-terminal region of the pfcsp gene. Methods A cross-sectional molecular study was conducted; 50 blood samples have been analysed from different regions in Sudan. Patients were recruited from the health facilities of Khartoum, New Halfa, Red Sea, White Nile, Al Qadarif, Gezira, River Nile, and Ad Damazin during malaria transmission seasons between June to October and December to February 2017–2018. Microscopic and nested PCR was performed for detection of P. falciparum. Merozoite surface protein-1 was performed to differentiate single and multiple clonal infections. The N-terminal of the pfcsp gene has been sequenced using PCR-Sanger dideoxy method and analysed to sequences polymorphism including the numbers of haplotypes (H), segregating sites (S), haplotypes diversity (Hd) and the average number of nucleotide differences between two sequences (Pi) were obtained using the software DnaSP v5.10. As well as neutrality testing, Tajima’s D test, Fu and Li’s D and F statistics. Results PCR amplification resulted in 1200 bp of the pfcsp gene. Only 21 PCR products were successfully sequenced while 29 were presenting multiple clonal P. falciparum parasite were not sequenced. The analysis of the N-terminal region of the PfCSP amino acids sequence compared to the reference strains showed five different haplotypes. H1 consisted of 3D7, NF54, HB3 and 13 isolates of the Sudanese pfcsp. H2 comprised of 7G8, Dd2, MAD20, RO33, Wellcome strain, and 5 isolates of the Sudanese pfcsp. H3, H4, and H5 were found in 3 distinct isolates. Hd was 0.594 ± 0.065, and S was 12. The most common polymorphic site was A98G; other sites were D82Y, N83H, N83M, K85L, L86F, R87L, R87F, and A98S. Fu and Li’s D* test value was − 2.70818, Fu and Li’s F* test value was − 2.83907, indicating a role of negative balancing selection in the pfcsp N-terminal region. Analysis with the global pfcsp N-terminal regions showed the presence of 13 haplotypes. Haplotypes frequencies were 79.4%, 17.0%, 1.6% and 1.0% for H1, H2, H3 and H4, respectively. Remaining haplotypes frequency was 0.1% for each. Hd was 0.340 ± 0.017 with a Pi of 0.00485, S was 18 sites, and Pi was 0.00030. Amino acid polymorphisms identified in the N-terminal region of global pfcsp were present at eight positions (D82Y, N83H/M, K85L/T/N, L86F, R87L/F, A98G/V/S, D99G, and G100D). Conclusions Sudanese pfcsp N-terminal region was well-conserved with only a few polymorphic sites. Geographical distribution of genetic diversity showed high similarity to the African isolates, and this will help and contribute in the deployment of RTS,S, a PfCSP-based vaccine, in Sudan.
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Affiliation(s)
- Nouh S Mohamed
- Department of Parasitology and Medical Entomology, Faculty of Medical Laboratory Sciences, Nile College, Khartoum, Sudan. .,Department of Parasitology and Medical Entomology, Faculty of Medical Laboratory Sciences, Sinnar University, Sinnar, Sudan. .,Department of Molecular Biology, Institute of Zoology, University of Hohenheim, Stuttgart, Germany.
| | - Musab M Ali Albsheer
- Department of Parasitology and Medical Entomology, Faculty of Medical Laboratory Sciences, Sinnar University, Sinnar, Sudan.,Department of Parasitology and Medical Entomology, East Nile College, Khartoum, Sudan
| | - Hanadi Abdelbagi
- Biotechnology Research Laboratory, School of Pharmacy, Ahfad University for Women, Omdurman, Sudan
| | - Emanuel E Siddig
- Unit of Applied Medical Sciences, Faculty of Medical Laboratory Sciences, University of Khartoum, Khartoum, Sudan.,Mycetoma Research Center, University of Khartoum, Khartoum, Sudan
| | - Mona A Mohamed
- Department of Parasitology and Medical Entomology, Faculty of Medical Laboratory Sciences, Nile College, Khartoum, Sudan
| | - Abdallah E Ahmed
- Department of Parasitology and Medical Entomology, Faculty of Medical Laboratory Sciences, Nile College, Khartoum, Sudan
| | - Rihab Ali Omer
- Department of Molecular Biology, Institute of Zoology, University of Hohenheim, Stuttgart, Germany.,Department of Molecular Biology, Institute of Parasitology, University of Leipzig, Leipzig, Germany
| | - Mohamed S Muneer
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA.,Department of Neurosurgery, Mayo Clinic, Jacksonville, FL, USA.,Department of Internal Medicine, Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Ayman Ahmed
- Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan.,World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch, Galveston, TX, USA
| | - Hussam A Osman
- Biotechnology Research Laboratory, School of Pharmacy, Ahfad University for Women, Omdurman, Sudan
| | - Mohamed S Ali
- Faculty of Medicine, Neelain University, Khartoum, Sudan
| | - Ibrahim M Eisa
- Department of Parasitology and Medical Entomology, Faculty of Medical Laboratory Sciences, Alzaiem Alazhari University, Khartoum, Sudan
| | - Mohamed M Elbasheir
- Department of Parasitology and Medical Entomology, Faculty of Medical Laboratory Sciences, Alzaiem Alazhari University, Khartoum, Sudan
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Zenklusen I, Jongo S, Abdulla S, Ramadhani K, Lee Sim BK, Cardamone H, Flannery EL, Nguyen T, Fishbaugher M, Steel RWJ, Betz W, Carmago N, Mikolajczak S, Kappe SHI, Hoffman SL, Sack BK, Daubenberger C. Immunization of Malaria-Preexposed Volunteers With PfSPZ Vaccine Elicits Long-Lived IgM Invasion-Inhibitory and Complement-Fixing Antibodies. J Infect Dis 2019; 217:1569-1578. [PMID: 29438525 DOI: 10.1093/infdis/jiy080] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/06/2018] [Indexed: 01/17/2023] Open
Abstract
Background The assessment of antibody responses after immunization with radiation-attenuated, aseptic, purified, cryopreserved Plasmodium falciparum sporozoites (Sanaria PfSPZ Vaccine) has focused on IgG isotype antibodies. Here, we aimed to investigate if P. falciparum sporozoite binding and invasion-inhibitory IgM antibodies are induced following immunization of malaria-preexposed volunteers with PfSPZ Vaccine. Methods Using serum from volunteers immunized with PfSPZ, we measured vaccine-induced IgG and IgM antibodies to P. falciparum circumsporozoite protein (PfCSP) via ELISA. Function of this serum as well as IgM antibody fractions was measured via in vitro in an inhibition of sporozoite invasion assay. These IgM antibody fractions were also measured for binding to sporozoites by immunofluorescence assay and complement fixation on whole sporozoites. Results We found that in addition to anti-PfCSP IgG, malaria-preexposed volunteers developed anti-PfCSP IgM antibodies after immunization with PfSPZ Vaccine and that these IgM antibodies inhibited P. falciparum sporozoite invasion of hepatocytes in vitro. These IgM plasma fractions also fixed complement to whole P. falciparum sporozoites. Conclusions This is the first finding that PfCSP and P. falciparum sporozoite-binding IgM antibodies are induced following immunization of PfSPZ Vaccine in malaria-preexposed individuals and that IgM antibodies can inhibit P. falciparum sporozoite invasion into hepatocytes in vitro and fix complement on sporozoites. These findings indicate that the immunological assessment of PfSPZ Vaccine-induced antibody responses could be more sensitive if they include parasite-specific IgM in addition to IgG antibodies. Clinical Trials Registration NCT02132299.
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Affiliation(s)
- Isabelle Zenklusen
- Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | - Said Jongo
- Ifakara Health Institute, Clinical Trial Unit, Bagamoyo, Tanzania
| | - Salim Abdulla
- Ifakara Health Institute, Clinical Trial Unit, Bagamoyo, Tanzania
| | - Kamaka Ramadhani
- Ifakara Health Institute, Clinical Trial Unit, Bagamoyo, Tanzania
| | | | | | | | - Thao Nguyen
- Center for Infectious Disease Research, Seattle, Washington
| | | | - Ryan W J Steel
- Center for Infectious Disease Research, Seattle, Washington
| | - Will Betz
- Center for Infectious Disease Research, Seattle, Washington
| | - Nelly Carmago
- Center for Infectious Disease Research, Seattle, Washington
| | | | - Stefan H I Kappe
- Center for Infectious Disease Research, Seattle, Washington.,Department of Global Health, University of Washington, Seattle
| | | | - Brandon K Sack
- Center for Infectious Disease Research, Seattle, Washington
| | - Claudia Daubenberger
- Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
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Julien JP, Wardemann H. Antibodies against Plasmodium falciparum malaria at the molecular level. Nat Rev Immunol 2019; 19:761-775. [DOI: 10.1038/s41577-019-0209-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2019] [Indexed: 12/11/2022]
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Penha-Gonçalves C. Genetics of Malaria Inflammatory Responses: A Pathogenesis Perspective. Front Immunol 2019; 10:1771. [PMID: 31417551 PMCID: PMC6682681 DOI: 10.3389/fimmu.2019.01771] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 07/15/2019] [Indexed: 12/27/2022] Open
Abstract
Despite significant progress in combating malaria in recent years the burden of severe disease and death due to Plasmodium infections remains a global public health concern. Only a fraction of infected people develops severe clinical syndromes motivating a longstanding search for genetic determinants of malaria severity. Strong genetic effects have been repeatedly ascribed to mutations and allelic variants of proteins expressed in red blood cells but the role of inflammatory response genes in disease pathogenesis has been difficult to discern. We revisited genetic evidence provided by inflammatory response genes that have been repeatedly associated to malaria, namely TNF, NOS2, IFNAR1, HMOX1, TLRs, CD36, and CD40LG. This highlighted specific genetic variants having opposing roles in the development of distinct malaria clinical outcomes and unveiled diverse levels of genetic heterogeneity that shaped the complex association landscape of inflammatory response genes with malaria. However, scrutinizing genetic effects of individual variants corroborates a pathogenesis model where pro-inflammatory genetic variants acting in early infection stages contribute to resolve infection but at later stages confer increased vulnerability to severe organ dysfunction driven by tissue inflammation. Human genetics studies are an invaluable tool to find genes and molecular pathways involved in the inflammatory response to malaria but their precise roles in disease pathogenesis are still unexploited. Genome editing in malaria experimental models and novel genotyping-by-sequencing techniques are promising approaches to delineate the relevance of inflammatory response gene variants in the natural history of infection thereby will offer new rational angles on adjuvant therapeutics for prevention and clinical management of severe malaria.
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Eacret JS, Gonzales DM, Franks RG, Burns JM. Immunization with merozoite surface protein 2 fused to a Plasmodium-specific carrier protein elicits strain-specific and strain-transcending, opsonizing antibody. Sci Rep 2019; 9:9022. [PMID: 31227760 PMCID: PMC6588637 DOI: 10.1038/s41598-019-45440-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 06/06/2019] [Indexed: 11/21/2022] Open
Abstract
Vaccine trials and cohort studies in Plasmodium falciparum endemic areas indicate that naturally-acquired and vaccine-induced antibodies to merozoite surface protein 2 (MSP2) are associated with resistance to malaria. These data indicate that PfMSP2 has significant potential as a component of a multi-antigen malaria vaccine. To overcome challenges encountered with subunit malaria vaccines, we established that the use of highly immunogenic rPfMSP8 as a carrier protein for leading vaccine candidates rPfMSP119 and rPfs25 facilitated antigen production, minimized antigenic competition and enhanced induction of functional antibodies. We applied this strategy to optimize a rPfMSP2 (3D7)-based subunit vaccine by producing unfused rPfMSP2 or chimeric rPfMSP2/8 in Escherichia coli. rPfMSP2 formed fibrils, which induced splenocyte proliferation in an antigen receptor-independent, TLR2-dependent manner. However, fusion to rPfMSP8 prevented rPfMSP2 amyloid-like fibril formation. Immunization of rabbits elicited high-titer anti-PfMSP2 antibodies that recognized rPfMSP2 of the 3D7 and FC27 alleles, as well as native PfMSP2. Competition assays revealed a difference in the specificity of antibodies induced by the two rPfMSP2-based vaccines, with evidence of epitope masking by rPfMSP2-associated fibrils. Rabbit anti-PfMSP2/8 was superior to rPfMSP2-elicited antibody at opsonizing P. falciparum merozoites for phagocytosis. These data establish rPfMSP8 as an effective carrier for a PfMSP2-based subunit malaria vaccine.
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Affiliation(s)
- Jacqueline S Eacret
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA
| | - Donna M Gonzales
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA
| | - Raymond G Franks
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA
| | - James M Burns
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA.
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Kurtovic L, Agius PA, Feng G, Drew DR, Ubillos I, Sacarlal J, Aponte JJ, Fowkes FJI, Dobaño C, Beeson JG. Induction and decay of functional complement-fixing antibodies by the RTS,S malaria vaccine in children, and a negative impact of malaria exposure. BMC Med 2019; 17:45. [PMID: 30798787 PMCID: PMC6388494 DOI: 10.1186/s12916-019-1277-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/31/2019] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Leading malaria vaccine, RTS,S, is based on the circumsporozoite protein (CSP) of sporozoites. RTS,S confers partial protection against malaria in children, but efficacy wanes relatively quickly after primary immunization. Vaccine efficacy has some association with anti-CSP IgG; however, it is unclear how these antibodies function, and how functional antibodies are induced and maintained over time. Recent studies identified antibody-complement interactions as a potentially important immune mechanism against sporozoites. Here, we investigated whether RTS,S vaccine-induced antibodies could function by interacting with complement. METHODS Serum samples were selected from children in a phase IIb trial of RTS,S/AS02A conducted at two study sites of high and low malaria transmission intensity in Manhiça, Mozambique. Samples following primary immunization and 5-year post-immunization follow-up time points were included. Vaccine-induced antibodies were characterized by isotype, subclass, and epitope specificity, and tested for the ability to fix and activate complement. We additionally developed statistical methods to model the decay and determinants of functional antibodies after vaccination. RESULTS RTS,S vaccination induced anti-CSP antibodies that were mostly IgG1, with some IgG3, IgG2, and IgM. Complement-fixing antibodies were effectively induced by vaccination, and targeted the central repeat and C-terminal regions of CSP. Higher levels of complement-fixing antibodies were associated with IgG that equally recognized both the central repeat and C-terminal regions of CSP. Older age and higher malaria exposure were significantly associated with a poorer induction of functional antibodies. There was a marked decay in functional complement-fixing antibodies within months after vaccination, as well as decays in IgG subclasses and IgM. Statistical modeling suggested the decay in complement-fixing antibodies was mostly attributed to the waning of anti-CSP IgG1, and to a lesser extent IgG3. CONCLUSIONS We demonstrate for the first time that RTS,S can induce complement-fixing antibodies in young malaria-exposed children. The short-lived nature of functional responses mirrors the declining vaccine efficacy of RTS,S over time. The negative influence of age and malaria exposure on functional antibodies has implications for understanding vaccine efficacy in different settings. These findings provide insights into the mechanisms and longevity of vaccine-induced immunity that will help inform the future development of highly efficacious and long-lasting malaria vaccines.
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Affiliation(s)
- Liriye Kurtovic
- Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Paul A Agius
- Burnet Institute, Melbourne, Australia.,Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Australia
| | | | | | - Itziar Ubillos
- ISGlobal, Hospital Clínic Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Jahit Sacarlal
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.,Faculdade de Medicina, Universidade Eduardo Mondlane (UEM), Maputo, Mozambique
| | - John J Aponte
- ISGlobal, Hospital Clínic Universitat de Barcelona, Barcelona, Catalonia, Spain.,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - Freya J I Fowkes
- Burnet Institute, Melbourne, Australia.,Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Carlota Dobaño
- ISGlobal, Hospital Clínic Universitat de Barcelona, Barcelona, Catalonia, Spain.,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | - James G Beeson
- Burnet Institute, Melbourne, Australia. .,Department of Immunology and Pathology, Monash University, Melbourne, Australia. .,Department of Microbiology, Monash University, Clayton, Australia. .,Department of Medicine, The University of Melbourne, Parkville, Australia.
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Wilson DS, Hirosue S, Raczy MM, Bonilla-Ramirez L, Jeanbart L, Wang R, Kwissa M, Franetich JF, Broggi MAS, Diaceri G, Quaglia-Thermes X, Mazier D, Swartz MA, Hubbell JA. Antigens reversibly conjugated to a polymeric glyco-adjuvant induce protective humoral and cellular immunity. NATURE MATERIALS 2019; 18:175-185. [PMID: 30643235 DOI: 10.1038/s41563-018-0256-5] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 11/20/2018] [Indexed: 05/17/2023]
Abstract
Fully effective vaccines for complex infections must elicit a diverse repertoire of antibodies (humoral immunity) and CD8+ T-cell responses (cellular immunity). Here, we present a synthetic glyco-adjuvant named p(Man-TLR7), which, when conjugated to antigens, elicits robust humoral and cellular immunity. p(Man-TLR7) is a random copolymer composed of monomers that either target dendritic cells (DCs) via mannose-binding receptors or activate DCs via Toll-like receptor 7 (TLR7). Protein antigens are conjugated to p(Man-TLR7) via a self-immolative linkage that releases chemically unmodified antigen after endocytosis, thus amplifying antigen presentation to T cells. Studies with ovalbumin (OVA)-p(Man-TLR7) conjugates demonstrate that OVA-p(Man-TLR7) generates greater humoral and cellular immunity than OVA conjugated to polymers lacking either mannose targeting or TLR7 ligand. We show significant enhancement of Plasmodium falciparum-derived circumsporozoite protein (CSP)-specific T-cell responses, expansion in the breadth of the αCSP IgG response and increased inhibition of sporozoite invasion into hepatocytes with CSP-p(Man-TLR7) when compared with CSP formulated with MPLA/QS-21-loaded liposomes-the adjuvant used in the most clinically advanced malaria vaccine. We conclude that our antigen-p(Man-TLR7) platform offers a strategy to enhance the immunogenicity of protein subunit vaccines.
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Affiliation(s)
- D Scott Wilson
- Institute for Bioengineering, School of Life Science and School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Sachiko Hirosue
- Institute for Bioengineering, School of Life Science and School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Michal M Raczy
- Institute for Bioengineering, School of Life Science and School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Leonardo Bonilla-Ramirez
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, CIMI, Paris, France
| | - Laura Jeanbart
- Institute for Bioengineering, School of Life Science and School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ruyi Wang
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Marcin Kwissa
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Jean-Francois Franetich
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, CIMI, Paris, France
| | - Maria A S Broggi
- Institute for Bioengineering, School of Life Science and School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Giacomo Diaceri
- Institute for Bioengineering, School of Life Science and School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Xavier Quaglia-Thermes
- Institute for Bioengineering, School of Life Science and School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Dominique Mazier
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, CIMI, Paris, France
| | - Melody A Swartz
- Institute for Bioengineering, School of Life Science and School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Jeffrey A Hubbell
- Institute for Bioengineering, School of Life Science and School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
- Institute for Molecular Engineering, University of Chicago, Chicago, IL, USA.
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Lê HG, Kang JM, Moe M, Jun H, Thái TL, Lee J, Myint MK, Lin K, Sohn WM, Shin HJ, Kim TS, Na BK. Genetic polymorphism and natural selection of circumsporozoite surface protein in Plasmodium falciparum field isolates from Myanmar. Malar J 2018; 17:361. [PMID: 30314440 PMCID: PMC6186114 DOI: 10.1186/s12936-018-2513-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/08/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium falciparum circumsporozoite protein (PfCSP) is one of the most extensively studied malaria vaccine candidates, but the genetic polymorphism of PfCSP within and among the global P. falciparum population raises concerns regarding the efficacy of a PfCSP-based vaccine efficacy. In this study, genetic diversity and natural selection of PfCSP in Myanmar as well as global P. falciparum were comprehensively analysed. METHODS Blood samples were collected from 51 P. falciparum infected Myanmar patients. Fifty-one full-length PfCSP genes were amplified from the blood samples through a nested polymerase chain reaction, cloned into a TA cloning vector, and then sequenced. Polymorphic characteristics and natural selection of Myanmar PfCSP were analysed using the DNASTAR, MEGA6, and DnaSP programs. Polymorphic diversity and natural selection in publicly available global PfCSP were also analysed. RESULTS The N-terminal and C-terminal non-repeat regions of Myanmar PfCSP showed limited genetic variations. A comparative analysis of the two regions in global PfCSP displayed similar patterns of low genetic diversity in global population, but substantial geographic differentiation was also observed. The most notable polymorphisms identified in the N-terminal region of global PfCSP were A98G and 19-amino acid length insertion in global population with different frequencies. Major polymorphic characters in the C-terminal region of Myanmar and global PfCSP were found in the Th2R and Th3R regions, where natural selection and recombination occurred. The central repeat region of Myanmar PfCSP was highly polymorphic, with differing numbers of repetitive repeat sequences NANP and NVDP. The numbers of the NANP repeats varied among global PfCSP, with the highest number of repeats seen in Asian and Oceanian PfCSP. Haplotype network analysis of global PfCSP revealed that global PfCSP clustered into 103 different haplotypes with geographically-separated populations. CONCLUSION Myanmar and global PfCSP displayed genetic diversity. N-terminal and C-terminal non-repeat regions were relatively conserved, but the central repeat region displayed high levels of genetic polymorphism in Myanmar and global PfCSP. The observed geographic pattern of genetic differentiation and the points of evidence for natural selection and recombination suggest that the functional consequences of the polymorphism should be considered for developing a vaccine based on PfCSP.
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Affiliation(s)
- Hương Giang Lê
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea.,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea.,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Mya Moe
- Department of Medical Research Pyin Oo Lwin Branch, Pyin Oo Lwin, Myanmar
| | - Hojong Jun
- Department of Tropical Medicine and Inha Research Institute for Medical Sciences, Inha University College of Medicine, Incheon, 22212, Republic of Korea
| | - Thị Lam Thái
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea.,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Jinyoung Lee
- Department of Tropical Medicine and Inha Research Institute for Medical Sciences, Inha University College of Medicine, Incheon, 22212, Republic of Korea
| | - Moe Kyaw Myint
- Department of Medical Research Pyin Oo Lwin Branch, Pyin Oo Lwin, Myanmar
| | - Khin Lin
- Department of Medical Research Pyin Oo Lwin Branch, Pyin Oo Lwin, Myanmar
| | - Woon-Mok Sohn
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea
| | - Ho-Joon Shin
- Department of Microbiology, Ajou University College of Medicine, Suwon, 16499, Republic of Korea
| | - Tong-Soo Kim
- Department of Tropical Medicine and Inha Research Institute for Medical Sciences, Inha University College of Medicine, Incheon, 22212, Republic of Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea. .,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea.
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Oyen D, Torres JL, Cottrell CA, Richter King C, Wilson IA, Ward AB. Cryo-EM structure of P. falciparum circumsporozoite protein with a vaccine-elicited antibody is stabilized by somatically mutated inter-Fab contacts. SCIENCE ADVANCES 2018; 4:eaau8529. [PMID: 30324137 PMCID: PMC6179375 DOI: 10.1126/sciadv.aau8529] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/07/2018] [Indexed: 05/29/2023]
Abstract
The circumsporozoite protein (CSP) on the surface of Plasmodium falciparum sporozoites is important for parasite development, motility, and host hepatocyte invasion. However, intrinsic disorder of the NANP repeat sequence in the central region of CSP has hindered its structural and functional characterization. Here, the cryo-electron microscopy structure at ~3.4-Å resolution of a recombinant shortened CSP construct with the variable domains (Fabs) of a highly protective monoclonal antibody reveals an extended spiral conformation of the central NANP repeat region surrounded by antibodies. This unusual structure appears to be stabilized and/or induced by interaction with an antibody where contacts between adjacent Fabs are somatically mutated and enhance the interaction. This maturation in non-antigen contact residues may be an effective mechanism for antibodies to target tandem repeat sequences and provide novel insights into malaria vaccine design.
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Affiliation(s)
- David Oyen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jonathan L. Torres
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Christopher A. Cottrell
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - C. Richter King
- PATH’s Malaria Vaccine Initiative, PATH’s Center for Vaccine Innovation and Access, Washington, DC 20001, USA
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Andrew B. Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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Pandey RK, Ali M, Ojha R, Bhatt TK, Prajapati VK. Development of multi-epitope driven subunit vaccine in secretory and membrane protein of Plasmodium falciparum to convey protection against malaria infection. Vaccine 2018; 36:4555-4565. [PMID: 29921492 DOI: 10.1016/j.vaccine.2018.05.082] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/20/2018] [Accepted: 05/22/2018] [Indexed: 10/28/2022]
Abstract
Malaria infection is the severe health concern for a long time. As per the WHO reports, the malarial infection causes huge mortality all around the world and is incomparable with any other infectious diseases. The absence of effective treatment options and increasing drug resistance to the available therapeutics like artemisinin and other derivatives demand an efficient alternative to overcome this death burden. Here, we performed the literature survey and sorted the Plasmodium falciparum secretory and membrane proteins to design multi-epitope subunit vaccine using an adjuvant, B-cell- and T-cell epitopes. Every helper T-lymphocyte (HTL) epitope was IFN-γ positive and IL-4 non-inducer. The physicochemical properties, allergenicity, and antigenicity of designed vaccine were analyzed for the safety concern. Homology modeling and refinement were performed to obtain the functional tertiary structure of vaccine protein followed by its molecular docking with the toll-like receptor-4 (TLR-4) immune receptor. Molecular dynamics simulation was performed to check the interaction and stability of the receptor-ligand complex. Lastly, in silico cloning was performed to generate the restriction clone of designed vaccine for the futuristic expression in a microbial expression system. This way, we designed the multi-epitope subunit vaccine to serve the people living in the global endemic zone.
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Affiliation(s)
- Rajan Kumar Pandey
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan 305817, India
| | - Mudassar Ali
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan 305817, India
| | - Rupal Ojha
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan 305817, India
| | - Tarun Kumar Bhatt
- Department of Biotechnology, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan 305817, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan 305817, India.
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A human monoclonal antibody prevents malaria infection by targeting a new site of vulnerability on the parasite. Nat Med 2018; 24:408-416. [PMID: 29554083 PMCID: PMC5893371 DOI: 10.1038/nm.4512] [Citation(s) in RCA: 182] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 01/26/2018] [Indexed: 01/07/2023]
Abstract
Development of a highly effective vaccine or antibodies for the prevention and ultimately elimination of malaria is urgently needed. Here we report the isolation of a number of human monoclonal antibodies directed against the Plasmodium falciparum (Pf) circumsporozoite protein (PfCSP) from several subjects immunized with an attenuated Pf whole-sporozoite (SPZ) vaccine (Sanaria PfSPZ Vaccine). Passive transfer of one of these antibodies, monoclonal antibody CIS43, conferred high-level, sterile protection in two different mouse models of malaria infection. The affinity and stoichiometry of CIS43 binding to PfCSP indicate that there are two sequential multivalent binding events encompassing the repeat domain. The first binding event is to a unique 'junctional' epitope positioned between the N terminus and the central repeat domain of PfCSP. Moreover, CIS43 prevented proteolytic cleavage of PfCSP on PfSPZ. Analysis of crystal structures of the CIS43 antigen-binding fragment in complex with the junctional epitope determined the molecular interactions of binding, revealed the epitope's conformational flexibility and defined Asn-Pro-Asn (NPN) as the structural repeat motif. The demonstration that CIS43 is highly effective for passive prevention of malaria has potential application for use in travelers, military personnel and elimination campaigns and identifies a new and conserved site of vulnerability on PfCSP for next-generation rational vaccine design.
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Davies HM, Nofal SD, McLaughlin EJ, Osborne AR. Repetitive sequences in malaria parasite proteins. FEMS Microbiol Rev 2018; 41:923-940. [PMID: 29077880 DOI: 10.1093/femsre/fux046] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 09/13/2017] [Indexed: 12/13/2022] Open
Abstract
Five species of parasite cause malaria in humans with the most severe disease caused by Plasmodium falciparum. Many of the proteins encoded in the P. falciparum genome are unusually enriched in repetitive low-complexity sequences containing a limited repertoire of amino acids. These repetitive sequences expand and contract dynamically and are among the most rapidly changing sequences in the genome. The simplest repetitive sequences consist of single amino acid repeats such as poly-asparagine tracts that are found in approximately 25% of P. falciparum proteins. More complex repeats of two or more amino acids are also common in diverse parasite protein families. There is no universal explanation for the occurrence of repetitive sequences and it is possible that many confer no function to the encoded protein and no selective advantage or disadvantage to the parasite. However, there are increasing numbers of examples where repetitive sequences are important for parasite protein function. We discuss the diverse roles of low-complexity repetitive sequences throughout the parasite life cycle, from mediating protein-protein interactions to enabling the parasite to evade the host immune system.
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Affiliation(s)
- Heledd M Davies
- The Francis Crick Institute, London, NW1 1AT, United Kingdom
| | - Stephanie D Nofal
- London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Emilia J McLaughlin
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Andrew R Osborne
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom.,Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, Malet Street, London, WC1E 7HX, United Kingdom
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Development of quantitative suspension array assays for six immunoglobulin isotypes and subclasses to multiple Plasmodium falciparum antigens. J Immunol Methods 2018; 455:41-54. [PMID: 29397157 DOI: 10.1016/j.jim.2018.01.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/19/2018] [Accepted: 01/24/2018] [Indexed: 12/23/2022]
Abstract
BACKGROUND Quantitative suspension arrays are powerful immunoassays to measure antibodies against multiple antigens in large numbers of samples in a short time and using few microliters. To identify antigen targets of immunity for vaccine development against complex microbes like Plasmodium falciparum, such technology allows the characterization of the magnitude and antigenic specificity of Ig isotypes and subclasses that are important for functional responses. However, standardized assays are not widely available. METHODS We developed six quantitative suspension array assays to measure IgG1, IgG2, IgG3, IgG4, IgM and IgE specific to multiple P. falciparum antigens. Secondary and tertiary antibodies, as well as human purified antibodies for standard curves, were tested among several commercially available sources. Positive and negative controls included plasmas from malaria hyper-immune African adults and from malaria-naïve European adults, respectively. Reagents were selected and optimal antibody and test sample dilutions established according to sensitivity, specificity and performance of the standard curves. The variability between replicates and plates was assessed with 30 test samples and controls. RESULTS Assays were able to detect P. falciparum antigen-specific antibodies for all isotypes and subclasses in samples from malaria-exposed individuals, with low background signal in blank wells. Levels detected in malaria-naïve individuals were overall low except for IgM. For the IgG2 and IgE assays, a triple sandwich was required for sensitivity. Standard curves with 5-parameter logistic fit were successfully obtained in all assays. The coefficients of variation for measurements performed in different days were all <30%, and <5% when comparing duplicates from the same plate. CONCLUSION The isotype/subclass assays developed here were sensitive, specific, reproducible and of adequate quantification dynamic range. They allow performing detailed immuno-profiling to large panels of P. falciparum antigens to address naturally- and vaccine-induced Ig responses and elucidate correlates of malaria protection, and could also be applied to other antigenic panels.
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Moris P, Jongert E, van der Most RG. Characterization of T-cell immune responses in clinical trials of the candidate RTS,S malaria vaccine. Hum Vaccin Immunother 2017; 14:17-27. [PMID: 28934066 PMCID: PMC5791571 DOI: 10.1080/21645515.2017.1381809] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The candidate malaria vaccine RTS,S has demonstrated 45.7% efficacy over 18 months against all clinical disease in a phase-III field study of African children. RTS,S targets the circumsporozoite protein (CSP), which is expressed on the Plasmodium sporozoite during the pre-erythrocyte stage of its life-cycle; the stage between mosquito bite and liver infection. Early in the development of RTS,S, it was recognized that CSP-specific cell-mediated immunity (CMI) was required to complement CSP-specific antibody-mediated immunity. In reviewing RTS,S clinical studies, associations between protection and various types of CMI (CSP-specific CD4+ T cells and INF-γ ELISPOTs) have been identified, but not consistently. It is plausible that certain CD4+ T cells support antibody responses or co-operate with other immune-cell types to potentially elicit protection. However, the identities of vaccine correlates of protection, implicating either CSP-specific antibodies or T cells remain elusive, suggesting that RTS,S clinical trials may benefit from additional immunogenicity analyses that can be informed by the results of controlled human malaria infection studies.
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