1
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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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2
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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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3
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Hayashi CTH, Cao Y, Zavala F, Simonyan H, Young CN, Kumar N. Antibodies elicited by Plasmodium falciparum circumsporozoite proteins lacking sequentially deleted C-terminal amino acids reveal mouse strain and epitopes specific differences. Vaccine 2023; 41:6824-6833. [PMID: 37827967 PMCID: PMC11004087 DOI: 10.1016/j.vaccine.2023.10.009] [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: 09/07/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/14/2023]
Abstract
Malaria affects ∼ ¼ billion people globally and requires the development of additional tools to aid in elimination efforts. The recently approved RTS,S/AS01 vaccine represents a positive step, however, the moderate efficacy necessitates the development of more efficacious vaccines. PfCSP is a key target antigen for pre-erythrocytic vaccines aimed at preventing Plasmodium falciparum malaria infections. Epitopes within the central repeat region and at the junction of the repeat and N-terminal domain are well documented as major protective B cell epitopes. On the other hand, a majority of antibodies against the epitopes in the C-terminal domain, have been shown to be non-protective against sporozoite challenge. The C-terminal domain, however, contains CD4+ and CD8+ T cell epitopes previously shown to be important for regulating immune responses. The present study was designed to further explore the immunomodulatory potential of the C-terminal domain using DNA vaccines encoding PfCSP with sequential C-terminal truncations following known T cell epitopes. Five DNA vaccines encoding different truncations of PfCSP within the C-terminal domain were administered via intramuscular route and in vivo electroporation for effective immunogenicity. Protection in mice was evaluated by challenge with transgenic P. berghei expressing PfCSP. In Balb/c mice, antibody responses and protective efficacy were both affected progressively with sequential deletion of C-terminal amino acid residues. Similar studies in C57Bl/6 mice revealed that immunizations with plasmids encoding truncated PfCSP showed partial protection from sporozoite challenge with no significant differences in antibody titers observed compared to full-length PfCSP DNA immunized mice. Further analysis revealed murine strain-specific differences in the recognition of specific epitopes.
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MESH Headings
- Animals
- Protozoan Proteins/immunology
- Protozoan Proteins/genetics
- Malaria Vaccines/immunology
- Malaria Vaccines/administration & dosage
- Malaria Vaccines/genetics
- Mice
- Plasmodium falciparum/immunology
- Plasmodium falciparum/genetics
- Antibodies, Protozoan/immunology
- Vaccines, DNA/immunology
- Vaccines, DNA/genetics
- Vaccines, DNA/administration & dosage
- Epitopes, T-Lymphocyte/immunology
- Epitopes, T-Lymphocyte/genetics
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/immunology
- Mice, Inbred BALB C
- Female
- Epitopes, B-Lymphocyte/immunology
- Epitopes, B-Lymphocyte/genetics
- Epitopes/immunology
- Epitopes/genetics
- Sporozoites/immunology
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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
| | - 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
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington DC 20052, USA
| | - Colin N Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington DC 20052, USA
| | - Nirbhay Kumar
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington DC 20052, USA.
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4
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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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5
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Oludada OE, Costa G, Burn Aschner C, Obraztsova AS, Prieto K, Canetta C, Hoffman SL, Kremsner PG, Mordmüller B, Murugan R, Julien JP, Levashina EA, Wardemann H. Molecular and functional properties of human Plasmodium falciparum CSP C-terminus antibodies. EMBO Mol Med 2023:e17454. [PMID: 37082831 DOI: 10.15252/emmm.202317454] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/11/2023] [Accepted: 03/23/2023] [Indexed: 04/22/2023] Open
Abstract
Human monoclonal antibodies (mAbs) against the central repeat and junction domain of Plasmodium falciparum circumsporozoite protein (PfCSP) have been studied extensively to guide malaria vaccine design compared to antibodies against the PfCSP C terminus. Here, we describe the molecular characteristics and protective potential of 73 germline and mutated human mAbs against the highly immunogenic PfCSP C-terminal domain. Two mAbs recognized linear epitopes in the C-terminal linker with sequence similarity to repeat and junction motifs, whereas all others targeted conformational epitopes in the α-thrombospondin repeat (α-TSR) domain. Specificity for the polymorphic Th2R/Th3R but not the conserved RII+/CS.T3 region in the α-TSR was associated with IGHV3-21/IGVL3-21 or IGLV3-1 gene usage. Although the C terminus specific mAbs showed signs of more efficient affinity maturation and class-switching compared to anti-repeat mAbs, live sporozoite binding and inhibitory activity was limited to a single C-linker reactive mAb with cross-reactivity to the central repeat and junction. The data provide novel insights in the human anti-C-linker and anti-α-TSR antibody response that support exclusion of the PfCSP C terminus from malaria vaccine designs.
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Affiliation(s)
- Opeyemi Ernest Oludada
- B Cell Immunology, German Cancer Research Center, Heidelberg, Germany
- Biosciences Faculty, University of Heidelberg, Germany
| | - Giulia Costa
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | | | - Anna S Obraztsova
- B Cell Immunology, German Cancer Research Center, Heidelberg, Germany
- Biosciences Faculty, University of Heidelberg, Germany
| | - Katherine Prieto
- The Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | - Caterina Canetta
- B Cell Immunology, German Cancer Research Center, Heidelberg, Germany
| | | | - Peter G Kremsner
- Institute of Tropical Medicine, Tübingen, Germany
- Centre de Recherches de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Benjamin Mordmüller
- Institute of Tropical Medicine, Tübingen, Germany
- Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rajagopal Murugan
- B Cell Immunology, German Cancer Research Center, Heidelberg, Germany
| | - Jean-Philippe Julien
- The Hospital for Sick Children Research Institute, Toronto, ON, Canada
- Departments of Biochemistry and Immunology, University of Toronto, Toronto, ON, Canada
| | - Elena A Levashina
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Hedda Wardemann
- B Cell Immunology, German Cancer Research Center, Heidelberg, Germany
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6
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Ludwig J, Scally SW, Costa G, Hoffmann S, Murugan R, Lossin J, Prieto K, Obraztcova A, Lobeto N, Franke-Fayard B, Janse CJ, Lebas C, Collin N, Binter S, Kellam P, Levashina EA, Wardemann H, Julien JP. Glycosylated nanoparticle-based PfCSP vaccine confers long-lasting antibody responses and sterile protection in mouse malaria model. NPJ Vaccines 2023; 8:52. [PMID: 37029167 PMCID: PMC10080175 DOI: 10.1038/s41541-023-00653-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Accepted: 03/23/2023] [Indexed: 04/09/2023] Open
Abstract
The development of an effective and durable vaccine remains a central goal in the fight against malaria. Circumsporozoite protein (CSP) is the major surface protein of sporozoites and the target of the only licensed Plasmodium falciparum (Pf) malaria vaccine, RTS,S/AS01. However, vaccine efficacy is low and short-lived, highlighting the need for a second-generation vaccine with superior efficacy and durability. Here, we report a Helicobacter pylori apoferritin-based nanoparticle immunogen that elicits strong B cell responses against PfCSP epitopes that are targeted by the most potent human monoclonal antibodies. Glycan engineering of the scaffold and fusion of an exogenous T cell epitope enhanced the anti-PfCSP B cell response eliciting strong, long-lived and protective humoral immunity in mice. Our study highlights the power of rational vaccine design to generate a highly efficacious second-generation anti-infective malaria vaccine candidate and provides the basis for its further development.
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Affiliation(s)
- Julia Ludwig
- B Cell Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephen W Scally
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada
- Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Giulia Costa
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Sandro Hoffmann
- B Cell Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Rajagopal Murugan
- B Cell Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jana Lossin
- B Cell Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Katherine Prieto
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada
- Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Anna Obraztcova
- B Cell Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Nina Lobeto
- B Cell Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Blandine Franke-Fayard
- Malaria Research Group, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Chris J Janse
- Malaria Research Group, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Celia Lebas
- Vaccine Formulation Institute, Plan-les-Ouates, Switzerland
| | - Nicolas Collin
- Vaccine Formulation Institute, Plan-les-Ouates, Switzerland
| | - Spela Binter
- Kymab a Sanofi Company, Babraham Research Campus, Cambridge, UK
| | - Paul Kellam
- Kymab a Sanofi Company, Babraham Research Campus, Cambridge, UK
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, UK
| | - Elena A Levashina
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.
| | - Hedda Wardemann
- B Cell Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada.
- Department of Immunology, University of Toronto, Toronto, ON, Canada.
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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7
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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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8
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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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9
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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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10
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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.
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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
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11
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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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12
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Tan J, Cho H, Pholcharee T, Pereira LS, Doumbo S, Doumtabe D, Flynn BJ, Schön A, Kanatani S, Aylor SO, Oyen D, Vistein R, Wang L, Dillon M, Skinner J, Peterson M, Li S, Idris AH, Molina-Cruz A, Zhao M, Olano LR, Lee PJ, Roth A, Sinnis P, Barillas-Mury C, Kayentao K, Ongoiba A, Francica JR, Traore B, Wilson IA, Seder RA, Crompton PD. Functional human IgA targets a conserved site on malaria sporozoites. Sci Transl Med 2021; 13:eabg2344. [PMID: 34162751 PMCID: PMC7611206 DOI: 10.1126/scitranslmed.abg2344] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/21/2021] [Indexed: 12/27/2022]
Abstract
Immunoglobulin (Ig)A antibodies play a critical role in protection against mucosal pathogens. However, the role of serum IgA in immunity to nonmucosal pathogens, such as Plasmodium falciparum, is poorly characterized, despite being the second most abundant isotype in blood after IgG. Here, we investigated the circulating IgA response in humans to P. falciparum sporozoites that are injected into the skin by mosquitoes and migrate to the liver via the bloodstream to initiate malaria infection. We found that circulating IgA was induced in three independent sporozoite-exposed cohorts: individuals living in an endemic region in Mali, malaria-naïve individuals immunized intravenously with three large doses of irradiated sporozoites, and malaria-naïve individuals exposed to a single controlled mosquito bite infection. Mechanistically, we found evidence in an animal model that IgA responses were induced by sporozoites at dermal inoculation sites. From malaria-resistant individuals, we isolated several IgA monoclonal antibodies that reduced liver parasite burden in mice. One antibody, MAD2-6, bound to a conserved epitope in the amino terminus of the P. falciparum circumsporozoite protein, the dominant protein on the sporozoite surface. Crystal structures of this antibody revealed a unique mode of binding whereby two Fabs simultaneously bound either side of the target peptide. This study reveals a role for circulating IgA in malaria and identifies the amino terminus of the circumsporozoite protein as a target of functional antibodies.
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Affiliation(s)
- Joshua Tan
- Antibody Biology Unit, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Rockville, MD 20852, USA.
| | - Hyeseon Cho
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Tossapol Pholcharee
- Department of Integrative Structural and Computational Biology, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Lais S Pereira
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Safiatou Doumbo
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, BP 1805, Point G, Bamako, Mali
| | - Didier Doumtabe
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, BP 1805, Point G, Bamako, Mali
| | - Barbara J Flynn
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Arne Schön
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sachie Kanatani
- Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Samantha O Aylor
- Department of Drug Discovery, Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - David Oyen
- Department of Integrative Structural and Computational Biology, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Rachel Vistein
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lawrence Wang
- 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
| | - Jeff Skinner
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Mary Peterson
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Shanping Li
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Azza H Idris
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alvaro Molina-Cruz
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Ming Zhao
- Protein Chemistry Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Lisa Renee Olano
- Protein Chemistry Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Patricia J Lee
- Department of Drug Discovery, Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Alison Roth
- Department of Drug Discovery, Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Photini Sinnis
- Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Carolina Barillas-Mury
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Kassoum Kayentao
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, BP 1805, Point G, Bamako, Mali
| | - Aissata Ongoiba
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, BP 1805, Point G, Bamako, Mali
| | - Joseph R Francica
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Boubacar Traore
- Mali International Center of Excellence in Research, University of Sciences, Technique and Technology of Bamako, BP 1805, Point G, Bamako, Mali
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, Scripps Research Institute, La Jolla, CA 92037, USA
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Robert A Seder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter D Crompton
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA.
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13
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Loubens M, Vincensini L, Fernandes P, Briquet S, Marinach C, Silvie O. Plasmodium sporozoites on the move: Switching from cell traversal to productive invasion of hepatocytes. Mol Microbiol 2021; 115:870-881. [PMID: 33191548 PMCID: PMC8247013 DOI: 10.1111/mmi.14645] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 12/18/2022]
Abstract
Parasites of the genus Plasmodium, the etiological agent of malaria, are transmitted through the bite of anopheline mosquitoes, which deposit sporozoites into the host skin. Sporozoites migrate through the dermis, enter the bloodstream, and rapidly traffic to the liver. They cross the liver sinusoidal barrier and traverse several hepatocytes before switching to productive invasion of a final one for replication inside a parasitophorous vacuole. Cell traversal and productive invasion are functionally independent processes that require proteins secreted from specialized secretory organelles known as micronemes. In this review, we summarize the current understanding of how sporozoites traverse through cells and productively invade hepatocytes, and discuss the role of environmental sensing in switching from a migratory to an invasive state. We propose that timely controlled secretion of distinct microneme subsets could play a key role in successful migration and infection of hepatocytes. A better understanding of these essential biological features of the Plasmodium sporozoite may contribute to the development of new strategies to fight against the very first and asymptomatic stage of malaria.
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Affiliation(s)
- Manon Loubens
- Centre d’Immunologie et des Maladies InfectieusesSorbonne Université, INSERM, CNRS, CIMI‐ParisParisFrance
| | - Laetitia Vincensini
- Centre d’Immunologie et des Maladies InfectieusesSorbonne Université, INSERM, CNRS, CIMI‐ParisParisFrance
| | - Priyanka Fernandes
- Centre d’Immunologie et des Maladies InfectieusesSorbonne Université, INSERM, CNRS, CIMI‐ParisParisFrance
| | - Sylvie Briquet
- Centre d’Immunologie et des Maladies InfectieusesSorbonne Université, INSERM, CNRS, CIMI‐ParisParisFrance
| | - Carine Marinach
- Centre d’Immunologie et des Maladies InfectieusesSorbonne Université, INSERM, CNRS, CIMI‐ParisParisFrance
| | - Olivier Silvie
- Centre d’Immunologie et des Maladies InfectieusesSorbonne Université, INSERM, CNRS, CIMI‐ParisParisFrance
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14
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Chatterjee D, Lewis FJ, Sutton HJ, Kaczmarski JA, Gao X, Cai Y, McNamara HA, Jackson CJ, Cockburn IA. Avid binding by B cells to the Plasmodium circumsporozoite protein repeat suppresses responses to protective subdominant epitopes. Cell Rep 2021; 35:108996. [PMID: 33852850 PMCID: PMC8052187 DOI: 10.1016/j.celrep.2021.108996] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 12/07/2020] [Accepted: 03/24/2021] [Indexed: 11/18/2022] Open
Abstract
Antibodies targeting the NANP/NVDP repeat domain of the Plasmodium falciparum circumsporozoite protein (CSPRepeat) can protect against malaria. However, it has also been suggested that the CSPRepeat is a decoy that prevents the immune system from mounting responses against other domains of CSP. Here, we show that, following parasite immunization, B cell responses to the CSPRepeat are immunodominant over responses to other CSP domains despite the presence of similar numbers of naive B cells able to bind these regions. We find that this immunodominance is driven by avid binding of the CSPRepeat to cognate B cells that are able to expand at the expense of B cells with other specificities. We further show that mice immunized with repeat-truncated CSP molecules develop responses to subdominant epitopes and are protected against malaria. These data demonstrate that the CSPRepeat functions as a decoy, but truncated CSP molecules may be an approach for malaria vaccination.
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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, ACT 2601, Australia
| | - Fiona J Lewis
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Henry J Sutton
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Joe A Kaczmarski
- Research School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia
| | - Xin Gao
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Yeping Cai
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Hayley A McNamara
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Colin J Jackson
- Research School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia
| | - Ian A Cockburn
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia.
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15
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Atcheson E, Hill AVS, Reyes-Sandoval A. A VLP for validation of the Plasmodium falciparum circumsporozoite protein junctional epitope for vaccine development. NPJ Vaccines 2021; 6:46. [PMID: 33795695 PMCID: PMC8016880 DOI: 10.1038/s41541-021-00302-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/12/2021] [Indexed: 11/18/2022] Open
Abstract
Malaria continues to be a pressing global health issue, causing nearly half a million deaths per year. An effective malaria vaccine could radically improve our ability to control and eliminate this pathogen. The most advanced malaria vaccine, RTS,S, confers only 30% protective efficacy under field conditions, and hence the search continues for improved vaccines. New antigens and formulations are always first developed at a pre-clinical level. This paper describes the development of a platform to supplement existing tools of pre-clinical malaria vaccine development, by displaying linear peptides on a virus-like particle (VLP). Peptides from PfCSP, particularly from outside the normal target of neutralizing antibodies, the central NANP repeat region, are screened for evidence of protective efficacy. One peptide, recently identified as a target of potent neutralizing antibodies and lying at the junction between the N-terminal domain and the central repeat region of PfCSP, is found to confer protective efficacy against malaria sporozoite challenge in mice when presented on the Qβ VLP. The platform is also used to explore the effects of increasing numbers of NANP unit repeats, and including a universal CD4+ T-cell epitope from tetanus toxin, on immunogenicity and protective efficacy. The VLP-peptide platform is shown to be of use in screening malaria peptides for protective efficacy and answering basic vaccinology questions in a pre-clinical setting.
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Affiliation(s)
| | | | - Arturo Reyes-Sandoval
- The Jenner Institute, University of Oxford, Oxford, UK. .,Instituto Politécnico Nacional, IPN. Av. Luis Enrique Erro s/n. Unidad Adolfo López Mateos, Mexico City, Mexico.
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16
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Kurtovic L, Wetzel D, Reiling L, Drew DR, Palmer C, Kouskousis B, Hanssen E, Wines BD, Hogarth PM, Suckow M, Jenzelewski V, Piontek M, Chan JA, Beeson JG. Novel Virus-Like Particle Vaccine Encoding the Circumsporozoite Protein of Plasmodium falciparum Is Immunogenic and Induces Functional Antibody Responses in Mice. Front Immunol 2021; 12:641421. [PMID: 33815393 PMCID: PMC8010251 DOI: 10.3389/fimmu.2021.641421] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/01/2021] [Indexed: 01/10/2023] Open
Abstract
RTS,S is the leading malaria vaccine in development, but has demonstrated only moderate protective efficacy in clinical trials. RTS,S is a virus-like particle (VLP) that uses the human hepatitis B virus as scaffold to display the malaria sporozoite antigen, circumsporozoite protein (CSP). Particle formation requires four-fold excess scaffold antigen, and as a result, CSP represents only a small portion of the final vaccine construct. Alternative VLP or nanoparticle platforms that reduce the amount of scaffold antigen and increase the amount of the target CSP antigen present in particles may enhance vaccine immunogenicity and efficacy. Here, we describe the production and characterization of a novel VLP that uses the small surface antigen (dS) of duck hepatitis B virus to display CSP. The CSP-dS fusion protein successfully formed VLPs without the need for excess scaffold antigen, and thus CSP represented a larger portion of the vaccine construct. CSP-dS formed large particles approximately 31-74 nm in size and were confirmed to display CSP on the surface. CSP-dS VLPs were highly immunogenic in mice and induced antibodies to multiple regions of CSP, even when administered at a lower vaccine dosage. Vaccine-induced antibodies demonstrated relevant functional activities, including Fc-dependent interactions with complement and Fcγ-receptors, previously identified as important in malaria immunity. Further, vaccine-induced antibodies had similar properties (epitope-specificity and avidity) to monoclonal antibodies that are protective in mouse models. Our novel platform to produce VLPs without excess scaffold protein has wide implications for the future development of vaccines for malaria and other infectious diseases.
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Affiliation(s)
- Liriye Kurtovic
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Departments of Immunology and Pathology and Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | | | - Linda Reiling
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
| | - Damien R. Drew
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
| | | | | | - Eric Hanssen
- The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Bruce D. Wines
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Departments of Immunology and Pathology and Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, Australia
- Clinical Pathology, The University of Melbourne, Parkville, VIC, Australia
| | - P. Mark Hogarth
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Departments of Immunology and Pathology and Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, Australia
- Clinical Pathology, The University of Melbourne, Parkville, VIC, Australia
| | | | | | | | - Jo-Anne Chan
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Departments of Immunology and Pathology and Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, Australia
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - James G. Beeson
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Departments of Immunology and Pathology and Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, Australia
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
- Department of Microbiology, Monash University, Clayton, VIC, Australia
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17
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Thai E, Costa G, Weyrich A, Murugan R, Oyen D, Flores-Garcia Y, Prieto K, Bosch A, Valleriani A, Wu NC, Pholcharee T, Scally SW, Wilson IA, Wardemann H, Julien JP, Levashina EA. A high-affinity antibody against the CSP N-terminal domain lacks Plasmodium falciparum inhibitory activity. J Exp Med 2021; 217:152019. [PMID: 32790871 PMCID: PMC7596816 DOI: 10.1084/jem.20200061] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/21/2020] [Accepted: 07/01/2020] [Indexed: 11/04/2022] Open
Abstract
Malaria is a global health concern, and research efforts are ongoing to develop a superior vaccine to RTS,S/AS01. To guide immunogen design, we seek a comprehensive understanding of the protective humoral response against Plasmodium falciparum (Pf) circumsporozoite protein (PfCSP). In contrast to the well-studied responses to the repeat region and the C-terminus, the antibody response against the N-terminal domain of PfCSP (N-CSP) remains obscure. Here, we characterized the molecular recognition and functional efficacy of the N-CSP-specific monoclonal antibody 5D5. The crystal structure at 1.85-Å resolution revealed that 5D5 binds an α-helical epitope in N-CSP with high affinity through extensive shape and charge complementarity and the unusual utilization of an antibody N-linked glycan. Nevertheless, functional studies indicated low 5D5 binding to live Pf sporozoites and lack of sporozoite inhibition in vitro and in vivo. Overall, our data do not support the inclusion of the 5D5 N-CSP epitope into the next generation of CSP-based vaccines.
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Affiliation(s)
- Elaine Thai
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Giulia Costa
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Anna Weyrich
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Rajagopal Murugan
- B Cell Immunology, German Cancer Research Institute, Heidelberg, Germany
| | - David Oyen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA
| | - Yevel Flores-Garcia
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Katherine Prieto
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Alexandre Bosch
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Angelo Valleriani
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.,Department of Theory and Biosystems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Nicholas C Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA
| | - Tossapol Pholcharee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA
| | - Stephen W Scally
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA.,The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA
| | - Hedda Wardemann
- B Cell Immunology, German Cancer Research Institute, Heidelberg, Germany
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Elena A Levashina
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
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18
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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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19
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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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20
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Friedman-Klabanoff DJ, Berry AA, Travassos MA, Cox C, Zhou Y, Mo AX, Nomicos EYH, Deye GA, Pasetti MF, Laurens MB. Low dose recombinant full-length circumsporozoite protein-based Plasmodium falciparum vaccine is well-tolerated and highly immunogenic in phase 1 first-in-human clinical testing. Vaccine 2021; 39:1195-1200. [PMID: 33494963 DOI: 10.1016/j.vaccine.2020.12.023] [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] [Received: 07/22/2020] [Revised: 11/18/2020] [Accepted: 12/08/2020] [Indexed: 01/19/2023]
Abstract
Plasmodium falciparum circumsporozoite protein (CSP) is a major sporozoite surface protein and a key target of pre-erythrocytic malaria subunit vaccines. A full-length recombinant CSP (rCSP) based strategy could be advantageous, as this antigen includes a region critical to sporozoite cell attachment and hepatocyte invasion. The adjuvant Glucopyranosyl Lipid A-liposome Quillaja saponaria 21 (GLA-LSQ) functions as a TLR4 agonist, promotes antigen-specific TH1 responses and stimulates cytotoxic T cell production. To date, one study has reported the clinical acceptability of GLA-LSQ. We present interim results of a phase 1 first-in-human dose-escalation clinical trial of full-length rCSP vaccine given with or without GLA-LSQ adjuvant. Participants experienced only mild to moderate related solicited adverse events. The lowest adjuvanted vaccine dose achieved >90-fold rise in geometric mean anti-CSP IgG antibody titer. These favorable safety and immunogenicity results confirm the immunostimulatory capacity of this relatively new adjuvant and support next steps in clinical product development. Trial registration: ClinicalTrials.gov Identifier NCT03589794 (registered 18 July 2018).
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Affiliation(s)
- DeAnna J Friedman-Klabanoff
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Andrea A Berry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mark A Travassos
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | | | - Annie X Mo
- Parasitology and International Programs Branch, Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Effie Y H Nomicos
- Parasitology and International Programs Branch, Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Gregory A Deye
- Parasitology and International Programs Branch, Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Marcela F Pasetti
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Matthew B Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
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21
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Jelínková L, Jhun H, Eaton A, Petrovsky N, Zavala F, Chackerian B. An epitope-based malaria vaccine targeting the junctional region of circumsporozoite protein. NPJ Vaccines 2021; 6:13. [PMID: 33479242 PMCID: PMC7820318 DOI: 10.1038/s41541-020-00274-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/11/2020] [Indexed: 01/29/2023] Open
Abstract
A malaria vaccine that elicits long-lasting protection and is suitable for use in endemic areas remains urgently needed. Here, we assessed the immunogenicity and prophylactic efficacy of a vaccine targeting a recently described epitope on the major surface antigen on Plasmodium falciparum sporozoites, circumsporozoite protein (CSP). Using a virus-like particle (VLP)-based vaccine platform technology, we developed a vaccine that targets the junctional region between the N-terminal and central repeat regions of CSP. This region is recognized by monoclonal antibodies, including mAb CIS43, that have been shown to potently prevent liver invasion in animal models. We show that CIS43 VLPs elicit high-titer and long-lived anti-CSP antibody responses in mice and is immunogenic in non-human primates. In mice, vaccine immunogenicity was enhanced by using mixed adjuvant formulations. Immunization with CIS43 VLPs conferred partial protection from malaria infection in a mouse model, and passive transfer of serum from immunized macaques also inhibited parasite liver invasion in the mouse infection model. Our findings demonstrate that a Qβ VLP-based vaccine targeting the CIS43 epitope combined with various adjuvants is highly immunogenic in mice and macaques, elicits long-lasting anti-CSP antibodies, and inhibits parasite infection in a mouse model. Thus, the CIS43 VLP vaccine is a promising pre-erythrocytic malaria vaccine candidate.
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Affiliation(s)
- Lucie Jelínková
- grid.266832.b0000 0001 2188 8502Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, New Mexico USA
| | - Hugo Jhun
- grid.21107.350000 0001 2171 9311W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD USA
| | - Allison Eaton
- grid.21107.350000 0001 2171 9311W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD USA
| | - Nikolai Petrovsky
- grid.451447.7Vaxine Pty Ltd, 11 Walkley Avenue, Warradale, Adelaide, SA 5046 Australia ,grid.1014.40000 0004 0367 2697College of Medicine and Public Health, Flinders University, Adelaide, SA 5042 Australia
| | - Fidel Zavala
- grid.21107.350000 0001 2171 9311W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD USA
| | - Bryce Chackerian
- grid.266832.b0000 0001 2188 8502Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, New Mexico USA
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22
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Identification of a neutralizing epitope within minor repeat region of Plasmodium falciparum CS protein. NPJ Vaccines 2021; 6:10. [PMID: 33462218 PMCID: PMC7813878 DOI: 10.1038/s41541-020-00272-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 12/14/2020] [Indexed: 11/08/2022] Open
Abstract
Malaria remains a major cause of morbidity and mortality worldwide with 219 million infections and 435,000 deaths predominantly in Africa. The infective Plasmodium sporozoite is the target of a potent humoral immune response that can protect murine, simian and human hosts against challenge by malaria-infected mosquitoes. Early murine studies demonstrated that sporozoites or subunit vaccines based on the sporozoite major surface antigen, the circumsporozoite (CS) protein, elicit antibodies that primarily target the central repeat region of the CS protein. In the current murine studies, using monoclonal antibodies and polyclonal sera obtained following immunization with P. falciparum sporozoites or synthetic repeat peptides, we demonstrate differences in the ability of these antibodies to recognize the major and minor repeats contained in the central repeat region. The biological relevance of these differences in fine specificity was explored using a transgenic P. berghei rodent parasite expressing the P. falciparum CS repeat region. In these in vitro and in vivo studies, we demonstrate that the minor repeat region, comprised of three copies of alternating NANP and NVDP tetramer repeats, contains an epitope recognized by sporozoite-neutralizing antibodies. In contrast, murine monoclonal antibodies specific for the major CS repeats (NANP)n could be isolated from peptide-immunized mice that had limited or no sporozoite-neutralizing activity. These studies highlight the importance of assessing the fine specificity and functions of antirepeat antibodies elicited by P. falciparum CS-based vaccines and suggest that the design of immunogens to increase antibody responses to minor CS repeats may enhance vaccine efficacy.
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23
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Subdominance in Antibody Responses: Implications for Vaccine Development. Microbiol Mol Biol Rev 2020; 85:85/1/e00078-20. [PMID: 33239435 DOI: 10.1128/mmbr.00078-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Vaccines work primarily by eliciting antibodies, even when recovery from natural infection depends on cellular immunity. Large efforts have therefore been made to identify microbial antigens that elicit protective antibodies, but these endeavors have encountered major difficulties, as witnessed by the lack of vaccines against many pathogens. This review summarizes accumulating evidence that subdominant protein regions, i.e., surface-exposed regions that elicit relatively weak antibody responses, are of particular interest for vaccine development. This concept may seem counterintuitive, but subdominance may represent an immune evasion mechanism, implying that the corresponding region potentially is a key target for protective immunity. Following a presentation of the concepts of immunodominance and subdominance, the review will present work on subdominant regions in several major human pathogens: the protozoan Plasmodium falciparum, two species of pathogenic streptococci, and the dengue and influenza viruses. Later sections are devoted to the molecular basis of subdominance, its potential role in immune evasion, and general implications for vaccine development. Special emphasis will be placed on the fact that a whole surface-exposed protein domain can be subdominant, as demonstrated for all of the pathogens described here. Overall, the available data indicate that subdominant protein regions are of much interest for vaccine development, not least in bacterial and protozoal systems, for which antibody subdominance remains largely unexplored.
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24
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Wang LT, Pereira LS, Flores-Garcia Y, O'Connor J, Flynn BJ, Schön A, Hurlburt NK, Dillon M, Yang ASP, Fabra-García A, Idris AH, Mayer BT, Gerber MW, Gottardo R, Mason RD, Cavett N, Ballard RB, Kisalu NK, Molina-Cruz A, Nelson J, Vistein R, Barillas-Mury C, Amino R, Baker D, King NP, Sauerwein RW, Pancera M, Cockburn IA, Zavala F, Francica JR, Seder RA. 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 PMCID: PMC7572793 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] [MESH Headings] [Grants] [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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Affiliation(s)
- Lawrence T Wang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lais S Pereira
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yevel Flores-Garcia
- Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - James O'Connor
- Department of Immunology and Infectious Diseases, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 0200, Australia; The Australian National University Medical School, Canberra, ACT 2601, Australia
| | - Barbara J Flynn
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Arne Schön
- Department of Biology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Nicholas K Hurlburt
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Marlon Dillon
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Annie S P Yang
- Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Amanda Fabra-García
- Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Azza H Idris
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bryan T Mayer
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Monica W Gerber
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Raphael Gottardo
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Rosemarie D Mason
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nicole Cavett
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Reid B Ballard
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Neville K Kisalu
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alvaro Molina-Cruz
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Jorgen Nelson
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Rachel Vistein
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Carolina Barillas-Mury
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Rogerio Amino
- Unit of Malaria Infection and Immunity, Institut Pasteur, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - David Baker
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Neil P King
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Robert W Sauerwein
- Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Marie Pancera
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Ian A Cockburn
- Department of Immunology and Infectious Diseases, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 0200, Australia
| | - Fidel Zavala
- Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Joseph R Francica
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, 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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25
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Antibody Feedback Limits the Expansion of B Cell Responses to Malaria Vaccination but Drives Diversification of the Humoral Response. Cell Host Microbe 2020; 28:572-585.e7. [PMID: 32697938 DOI: 10.1016/j.chom.2020.07.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 06/02/2020] [Accepted: 06/30/2020] [Indexed: 12/20/2022]
Abstract
Generating sufficient antibody to block infection is a key challenge for vaccines against malaria. Here, we show that antibody titers to a key target, the repeat region of the Plasmodium falciparum circumsporozoite protein (PfCSP), plateaued after two immunizations in a clinical trial of the radiation-attenuated sporozoite vaccine. To understand the mechanisms limiting vaccine responsiveness, we developed immunoglobulin (Ig)-knockin mice with elevated numbers of PfCSP-binding B cells. We determined that recall responses were inhibited by antibody feedback, potentially via epitope masking of the immunodominant PfCSP repeat region. Importantly, the amount of antibody that prevents boosting is below the amount of antibody required for protection. Finally, while antibody feedback limited responses to the PfCSP repeat region in vaccinated volunteers, potentially protective subdominant responses to PfCSP C-terminal regions expanded with subsequent boosts. These data suggest that antibody feedback drives the diversification of immune responses and that vaccination for malaria will require targeting multiple antigens.
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26
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Tripathi AK, Mlambo G, Kanatani S, Sinnis P, Dimopoulos G. Plasmodium falciparum Gametocyte Culture and Mosquito Infection Through Artificial Membrane Feeding. J Vis Exp 2020. [PMID: 32716382 DOI: 10.3791/61426] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Malaria remains one of the most important public health problems, causing significant morbidity and mortality. Malaria is a mosquito borne disease transmitted through an infectious bite from the female Anopheles mosquito. Malaria control will eventually rely on a multitude of approaches, which includes ways to block transmission to, through and from mosquitoes. To study mosquito stages of malaria parasites in the laboratory, we have optimized a protocol to culture highly infectious Plasmodium falciparum gametocytes, a parasite stage required for transmission from the human host to the mosquito vector. P. falciparum gametocytes mature through five morphologically distinct steps, which takes approximately 1-2 weeks. Gametocyte culture described in this protocol is completed in 15 days and are infectious to mosquitoes from days 15-18. These protocols were developed to maintain a continuous cycle of infection competent gametocytes and to maintain uninterrupted supply of mosquito stages of the parasite. Here, we describe the methodology of gametocyte culture and how to infect mosquitoes with these parasites using glass membrane feeders.
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Affiliation(s)
- Abhai K Tripathi
- Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University;
| | - Godfree Mlambo
- Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University
| | - Sachie Kanatani
- Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University
| | - Photini Sinnis
- Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University
| | - George Dimopoulos
- Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University
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27
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A Multistage Formulation Based on Full-Length CSP and AMA-1 Ectodomain of Plasmodium vivax Induces High Antibody Titers and T-cells and Partially Protects Mice Challenged with a Transgenic Plasmodium berghei Parasite. Microorganisms 2020; 8:microorganisms8060916. [PMID: 32560380 PMCID: PMC7356588 DOI: 10.3390/microorganisms8060916] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/13/2020] [Accepted: 06/14/2020] [Indexed: 01/23/2023] Open
Abstract
Infections with Plasmodium vivax are predominant in the Americas, representing 75% of malaria cases. Previously perceived as benign, malaria vivax is, in fact, a highly debilitating and economically important disease. Considering the high complexity of the malaria parasite life cycle, it has been hypothesized that an effective vaccine formulation against Plasmodium should contain multiple antigens expressed in different parasite stages. Based on that, we analyzed a recombinant P. vivax vaccine formulation mixing the apical membrane antigen 1 ectodomain (PvAMA-1) and a full-length circumsporozoite protein (PvCSP-AllFL) previously studied by our group, which elicits a potent antibody response in mice. Genetically distinct strains of mice (C57BL/6 and BALB/c) were immunized with the proteins, alone or in combination, in the presence of poly(I:C) adjuvant, a TLR3 agonist. In C57BL/6, high-antibody titers were induced against PvAMA-1 and the three PvCSP variants (VK210, VK247, and P. vivax-like). Meanwhile, mixing PvAMA-1 with PvCSP-AllFL had no impact on total IgG antibody titers, which were long-lasting. Moreover, antibodies from immunized mice recognized VK210 sporozoites and blood-stage parasites by immunofluorescence assay. However, in the BALB/c model, the antibody response against PvCSP-AllFL was relatively low. PvAMA-1-specific CD3+CD4+ and CD3+CD8+ T-cell responses were observed in C57BL/6 mice, and the cellular response was impaired by PvCSP-AllFL combination. More relevant, the multistage vaccine formulation provided partial protection in mice challenged with a transgenic Plasmodium berghei sporozoite expressing the homologous PvCSP protein.
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Smith EC, Limbach KJ, Rangel N, Oda K, Bolton JS, Du M, Gowda K, Wang J, Moch JK, Sonawane S, Velasco R, Belmonte A, Danner R, Lumsden JM, Patterson NB, Sedegah M, Hollingdale MR, Richie TL, Sacci JB, Villasante ED, Aguiar JC. Novel malaria antigen Plasmodium yoelii E140 induces antibody-mediated sterile protection in mice against malaria challenge. PLoS One 2020; 15:e0232234. [PMID: 32407410 PMCID: PMC7224506 DOI: 10.1371/journal.pone.0232234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 04/09/2020] [Indexed: 11/18/2022] Open
Abstract
Only a small fraction of the antigens expressed by malaria parasites have been evaluated as vaccine candidates. A successful malaria subunit vaccine will likely require multiple antigenic targets to achieve broad protection with high protective efficacy. Here we describe protective efficacy of a novel antigen, Plasmodium yoelii (Py) E140 (PyE140), evaluated against P. yoelii challenge of mice. Vaccines targeting PyE140 reproducibly induced up to 100% sterile protection in both inbred and outbred murine challenge models. Although PyE140 immunization induced high frequency and multifunctional CD8+ T cell responses, as well as CD4+ T cell responses, protection was mediated by PyE140 antibodies acting against blood stage parasites. Protection in mice was long-lasting with up to 100% sterile protection at twelve weeks post-immunization and durable high titer anti-PyE140 antibodies. The E140 antigen is expressed in all Plasmodium species, is highly conserved in both P. falciparum lab-adapted strains and endemic circulating parasites, and is thus a promising lead vaccine candidate for future evaluation against human malaria parasite species.
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Affiliation(s)
- Emily C. Smith
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Keith J. Limbach
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Nonenipha Rangel
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- CAMRIS International, Bethesda, Maryland, United States of America
| | - Kyosuke Oda
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- CAMRIS International, Bethesda, Maryland, United States of America
| | - Jessica S. Bolton
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Mengyan Du
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Kalpana Gowda
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Jianyang Wang
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- CAMRIS International, Bethesda, Maryland, United States of America
| | - J. Kathleen Moch
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
- Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Sharvari Sonawane
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Rachel Velasco
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Arnel Belmonte
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Rebecca Danner
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Joanne M. Lumsden
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Noelle B. Patterson
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Martha Sedegah
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Michael R. Hollingdale
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, Maryland, United States of America
| | - Thomas L. Richie
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - John B. Sacci
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Eileen D. Villasante
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
| | - Joao C. Aguiar
- Malaria Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America
- CAMRIS International, Bethesda, Maryland, United States of America
- * E-mail:
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Protective efficacy of peptides from Plasmodium vivax circumsporozoite protein. Vaccine 2020; 38:4346-4354. [PMID: 32402755 PMCID: PMC7408485 DOI: 10.1016/j.vaccine.2020.03.063] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 12/12/2022]
Abstract
Short repeat-region peptides from PvCSP on a VLP protect against malaria. The AGDR tetramer from PvCSP VK210 can, on a VLP, also protect against malaria. Full-length PvCSP is much less protective as a vaccine than truncated PvCSP. Region I and II peptides confer no protection against malaria presented on a VLP.
Vivax malaria is a major cause of morbidity and mortality worldwide, with several million clinical cases per year and 2.5 billion at risk of infection. A vaccine is urgently needed but the most advanced malaria vaccine, VMP001, confers only very low levels of protection against vivax malaria challenge in humans. VMP001 is based on the circumsporozoite protein (CSP) of Plasmodium vivax. Here a virus-like particle, Qβ, is used as a platform to generate very high levels of antibody against peptides from PvCSP in mice, in order to answer questions important to further development of P. vivax CSP (PvCSP) vaccines. Minimal peptides from the VK210 and VK247 allelic variants of PvCSP are found to be highly protective as Qβ-peptide vaccines, using transgenic P. berghei parasites expressing the homologous PvCSP allelic variant. A target of neutralising antibodies within the nonamer unit repeat of VK210, AGDR, is found, as a Qβ-peptide vaccine, to provide partial protection against malaria challenge, and enhances protective efficacy when combined with full-length PvCSP vaccination. A truncated form of PvCSP, missing the N-terminal domain, is found to confer much higher levels of protective efficacy than full-length PvCSP. Peptides derived from highly conserved areas of PvCSP, RI and RII, are found not to confer protective efficacy as Qβ-peptide vaccines.
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Chim-Ong A, Surit T, Chainarin S, Roobsoong W, Sattabongkot J, Cui L, Nguitragool W. The Blood Stage Antigen RBP2-P1 of Plasmodium vivax Binds Reticulocytes and Is a Target of Naturally Acquired Immunity. Infect Immun 2020; 88:e00616-19. [PMID: 32014895 PMCID: PMC7093139 DOI: 10.1128/iai.00616-19] [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: 08/19/2019] [Accepted: 01/21/2020] [Indexed: 11/20/2022] Open
Abstract
The interactions between Plasmodium parasites and human erythrocytes are prime targets of blood stage malaria vaccine development. The reticulocyte binding protein 2-P1 (RBP2-P1) of Plasmodium vivax, a member of the reticulocyte binding protein family, has recently been shown to be highly antigenic in several settings endemic for malaria. Yet, its functional characteristics and the relevance of its antibody response in human malaria have not been examined. In this study, the potential function of RBP2-P1 as an invasion ligand of P. vivax was evaluated. The protein was found to be expressed in schizonts, be localized at the apical end of the merozoite, and preferentially bind reticulocytes over normocytes. Human antibodies to this protein also exhibit erythrocyte binding inhibition at physiologically relevant concentrations. Furthermore, RBP2-P1 antibodies are associated with lower parasitemia and tend to be higher in asymptomatic carriers than in patients. This study provides evidence supporting a role of RBP2-P1 as an invasion ligand and its consideration as a vaccine target.
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Affiliation(s)
- Anongruk Chim-Ong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Thitiporn Surit
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sittinont Chainarin
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wanlapa Roobsoong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Wang Nguitragool
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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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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Optimization of a Plasmodium falciparum circumsporozoite protein repeat vaccine using the tobacco mosaic virus platform. Proc Natl Acad Sci U S A 2020; 117:3114-3122. [PMID: 31988134 PMCID: PMC7022184 DOI: 10.1073/pnas.1911792117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
RTS,S/AS01 is a circumsporozoite protein (CSP)-based malaria vaccine that confers partial protection against malaria in endemic areas. Recent reports have elucidated structures of monoclonal antibodies that bind to the central (NPNA) repeat region of CSP and that inhibit parasite invasion. Antigen configuration and copy number of CSP repeats displayed on a tobacco mosaic virus (TMV) particle platform were studied. A TMV vaccine containing CSP repeats displayed as a loop induced 10× better antibody titer than a nearly full-length CSP in mice. In rhesus model, this translated to a 5× improvement in titer. Rhesus antibodies potently inhibited parasite invasion up to 11 mo after vaccination. An optimized epitope-focused, repeat-only CSP vaccine may be sufficient or better than the existing CSP vaccines. Plasmodium falciparum vaccine RTS,S/AS01 is based on the major NPNA repeat and the C-terminal region of the circumsporozoite protein (CSP). RTS,S-induced NPNA-specific antibody titer and avidity have been associated with high-level protection in naïve subjects, but efficacy and longevity in target populations is relatively low. In an effort to improve upon RTS,S, a minimal repeat-only, epitope-focused, protective, malaria vaccine was designed. Repeat antigen copy number and flexibility was optimized using the tobacco mosaic virus (TMV) display platform. Comparing antigenicity of TMV displaying 3 to 20 copies of NPNA revealed that low copy number can reduce the abundance of low-affinity monoclonal antibody (mAb) epitopes while retaining high-affinity mAb epitopes. TMV presentation improved titer and avidity of repeat-specific Abs compared to a nearly full-length protein vaccine (FL-CSP). NPNAx5 antigen displayed as a loop on the TMV particle was found to be most optimal and its efficacy could be further augmented by combination with a human-use adjuvant ALFQ that contains immune-stimulators. These data were confirmed in rhesus macaques where a low dose of TMV-NPNAx5 elicited Abs that persisted at functional levels for up to 11 mo. We show here a complex association between NPNA copy number, flexibility, antigenicity, immunogenicity, and efficacy of CSP-based vaccines. We hypothesize that designing minimal epitope CSP vaccines could confer better and more durable protection against malaria. Preclinical data presented here supports the evaluation of TMV-NPNAx5/ALFQ in human trials.
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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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Martin ML, Bitzer AA, Schrader A, Bergmann-Leitner ES, Soto K, Zou X, Beck Z, Matyas GR, Dutta S. Comparison of immunogenicity and safety outcomes of a malaria vaccine FMP013/ALFQ in rhesus macaques (Macaca mulatta) of Indian and Chinese origin. Malar J 2019; 18:377. [PMID: 31775762 PMCID: PMC6880475 DOI: 10.1186/s12936-019-3014-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/18/2019] [Indexed: 11/21/2022] Open
Abstract
Background Indian-origin rhesus (InR) are preferred for research, but strict export restrictions continue to limit their use. Chinese-origin rhesus (ChR), although easier to procure, are genetically distinct from InR and differ in their immune response to infectious agents, such as the Simian Immunodeficiency Virus. The most advanced malaria vaccine, RTS,S (GlaxoSmithKline), is based on the circumsporozoite protein (CSP) of Plasmodium falciparum. The efficacy of RTS,S vaccine in the field remains low and short-lived; efforts are underway to improve CSP-based vaccines. Rhesus models can accelerate preclinical down-selection of the next generation of malaria vaccines. This study was used to determine if the safety and immunogenicity outcomes following vaccination with a CSP vaccine would differ in the InR and ChR models, given the genetic differences between the two sub-populations of rhesus. Methods The FMP013 vaccine, was composed of nearly full-length soluble P. falciparum CSP produced in Escherichia coli and was adjuvanted with the Army liposomal formulation (ALFQ). Three doses of the vaccine were administered in InR and ChR (n = 6) at 1-month intervals and the antibody and T cell responses were assessed. Results Local and systemic toxicity profile of FMP013 vaccine in InR and ChR were similar and they revealed that the FMP013 vaccine was safe and caused only mild and transient inflammatory adverse reactions. Following the first 2 vaccines, there was a slower acquisition of antibodies to the CSP repeat region in ChR. However after the 3rd vaccination the titers in the two models were comparable. The ChR group repeat-specific antibodies had higher avidity and ChR group showed higher inhibition of liver stage development activity compared to InR. There was no difference in T-cell responses to the FMP013 vaccine between the two models. Conclusions A difference in the quality of serological responses was detected between the two sub-populations of rhesus. However, both models confirmed that FMP013/ALFQ vaccine was safe, highly immunogenic, elicited functional antibodies and T-cell responses. Overall, the data suggests that rhesus of Indian and Chinese origins can be interchangeably used to compare the safety and immunogenicity of next-generation of malaria vaccines and adjuvants.
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Affiliation(s)
- Monica L Martin
- Division of Veterinary Medicine, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Alexis A Bitzer
- Structural Biologics Laboratory, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Andrew Schrader
- Division of Veterinary Medicine, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Elke S Bergmann-Leitner
- Immunology Core, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Kim Soto
- Structural Biologics Laboratory, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Xiaoyan Zou
- Malaria Department, Naval Medical Research Center, Silver Spring, MD, 20910, USA
| | - Zoltan Beck
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA.,Henry M. Jackson Foundation, Rockville, MD, 20852, USA
| | - Gary R Matyas
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Sheetij Dutta
- Structural Biologics Laboratory, Malaria Biologics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA.
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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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36
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Goh YS, McGuire D, Rénia L. Vaccination With Sporozoites: Models and Correlates of Protection. Front Immunol 2019; 10:1227. [PMID: 31231377 PMCID: PMC6560154 DOI: 10.3389/fimmu.2019.01227] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 05/14/2019] [Indexed: 12/14/2022] Open
Abstract
Despite continuous efforts, the century-old goal of eradicating malaria still remains. Multiple control interventions need to be in place simultaneously to achieve this goal. In addition to effective control measures, drug therapies and insecticides, vaccines are critical to reduce mortality and morbidity. Hence, there are numerous studies investigating various malaria vaccine candidates. Most of the malaria vaccine candidates are subunit vaccines. However, they have shown limited efficacy in Phase II and III studies. To date, only whole parasite formulations have been shown to induce sterile immunity in human. In this article, we review and discuss the recent developments in vaccination with sporozoites and the mechanisms of protection involved.
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Affiliation(s)
- Yun Shan Goh
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Biopolis, Singapore, Singapore
| | - Daniel McGuire
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Biopolis, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Laurent Rénia
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Biopolis, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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37
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Cawlfield A, Genito CJ, Beck Z, Bergmann-Leitner ES, Bitzer AA, Soto K, Zou X, Hadiwidjojo SH, Gerbasi RV, Mullins AB, Noe A, Waters NC, Alving CR, Matyas GR, Dutta S. Safety, toxicity and immunogenicity of a malaria vaccine based on the circumsporozoite protein (FMP013) with the adjuvant army liposome formulation containing QS21 (ALFQ). Vaccine 2019; 37:3793-3803. [PMID: 31151801 DOI: 10.1016/j.vaccine.2019.05.059] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 01/21/2023]
Abstract
Antibodies to Circumsporozoite protein (CSP) confer protection against controlled human malaria infection (CHMI) caused by the parasite Plasmodium falciparum. Although CSP is highly immunogenic, it does not induce long lasting protection and efforts to improve CSP-specific immunological memory and duration of protection are underway. We have previously reported that the clinical grade CSP vaccine FMP013 was immunogenic and protective against malaria challenge in mice when combined with the Army Liposomal Formulation adjuvant containing immune modulators 3D-PHAD™ and QS21 (ALFQ). To move forward with clinical evaluation, we now report the safety, toxicity and immunogenicity of clinical grade FMP013 and ALFQ in Rhesus macaques. Three groups of Rhesus (n = 6) received half or full human dose of FMP013 + ALFQ on a 0-1-2 month schedule, which showed mild local site reactions with no hematologic derangements in red blood cell homeostasis, liver function or kidney function. Immunization induced a transient systemic inflammatory response, including elevated white blood cell counts, mild fever, and a few incidences of elevated creatine kinase, receding to normal range by day 7 post vaccination. Optimal immunogenicity in Rhesus was observed using a 1 mL ALFQ + 20 µg FMP013 dose. Doubling the FMP013 antigen dose to 40 µg had no effect while halving the ALFQ adjuvant dose to 0.5 mL lowered immunogenicity. Similar to data generated in mice, FMP013 + ALFQ induced serum antibodies that reacted to all regions of the CSP molecule and a Th1-biased cytokine response in Rhesus. Rhesus antibody response to FMP013 + ALFQ was found to be non-inferior to historical benchmarks including that of RTS,S + AS01 in humans. A four-dose GLP toxicity study in rabbits confirmed no local site reactions and transient systemic inflammation associated with ALFQ adjuvant administration. These safety and immunogenicity data support the clinical progression and testing of FMP013 + ALFQ in a CHMI trial in the near future.
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Affiliation(s)
- Alicia Cawlfield
- Department of Veterinary Medicine, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Christopher J Genito
- Structural Vaccinology Laboratory, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Zoltan Beck
- Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, MD 20817, USA
| | - Elke S Bergmann-Leitner
- Flow-cytometeric Center, Malaria Vaccine Branch, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Alexis A Bitzer
- Structural Vaccinology Laboratory, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Kimberly Soto
- Structural Vaccinology Laboratory, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Xiaoyan Zou
- Malaria Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Sri H Hadiwidjojo
- Malaria Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Robert V Gerbasi
- Malaria Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Anna B Mullins
- Department of Veterinary Medicine, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Amy Noe
- Leidos Life Sciences, 5202 Presidents Court, Suite 110, Fredrick, MD 21703, USA
| | - Norman C Waters
- Malaria Vaccine Branch, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Carl R Alving
- Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Gary R Matyas
- Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Sheetij Dutta
- Structural Vaccinology Laboratory, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA.
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38
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Heide J, Vaughan KC, Sette A, Jacobs T, Schulze Zur Wiesch J. Comprehensive Review of Human Plasmodium falciparum-Specific CD8+ T Cell Epitopes. Front Immunol 2019; 10:397. [PMID: 30949162 PMCID: PMC6438266 DOI: 10.3389/fimmu.2019.00397] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 02/15/2019] [Indexed: 12/16/2022] Open
Abstract
Control of malaria is an important global health issue and there is still an urgent need for the development of an effective prophylactic vaccine. Multiple studies have provided strong evidence that Plasmodium falciparum-specific MHC class I-restricted CD8+ T cells are important for sterile protection against Plasmodium falciparum infection. Here, we present an interactive epitope map of all P. falciparum-specific CD8+ T cell epitopes published to date, based on a comprehensive data base (IEDB), and literature search. The majority of the described P. falciparum-specific CD8+ T cells were directed against the antigens CSP, TRAP, AMA1, and LSA1. Notably, most of the epitopes were discovered in vaccine trials conducted with malaria-naïve volunteers. Only few immunological studies of P. falciparum-specific CD8+ T cell epitopes detected in patients suffering from acute malaria or in people living in malaria endemic areas have been published. Further detailed immunological mappings of P. falciparum-specific epitopes of a broader range of P. falciparum proteins in different settings and with different disease status are needed to gain a more comprehensive understanding of the role of CD8+ T cell responses for protection, and to better guide vaccine design and to study their efficacy.
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Affiliation(s)
- Janna Heide
- Infectious Diseases Unit, I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Kerrie C Vaughan
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Alessandro Sette
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States.,Department of Medicine, Division of Infectious Diseases, University of California, San Diego (UCSD), La Jolla, CA, United States
| | - Thomas Jacobs
- Protozoa Immunology, Bernhard-Nocht-Institute of Tropical Medicine, Hamburg, Germany
| | - Julian Schulze Zur Wiesch
- Infectious Diseases Unit, I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
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39
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Abstract
The development of highly effective and durable vaccines against the human malaria parasites Plasmodium falciparum and P. vivax remains a key priority. Decades of endeavor have taught that achieving this goal will be challenging; however, recent innovation in malaria vaccine research and a diverse pipeline of novel vaccine candidates for clinical assessment provides optimism. With first-generation pre-erythrocytic vaccines aiming for licensure in the coming years, it is important to reflect on how next-generation approaches can improve on their success. Here we review the latest vaccine approaches that seek to prevent malaria infection, disease, and transmission and highlight some of the major underlying immunological and molecular mechanisms of protection. The synthesis of rational antigen selection, immunogen design, and immunization strategies to induce quantitatively and qualitatively improved immune effector mechanisms offers promise for achieving sustained high-level protection.
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40
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A probabilistic model of pre-erythrocytic malaria vaccine combination in mice. PLoS One 2019; 14:e0209028. [PMID: 30625136 PMCID: PMC6326473 DOI: 10.1371/journal.pone.0209028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 11/27/2018] [Indexed: 11/19/2022] Open
Abstract
Malaria remains one the world’s most deadly infectious diseases, with almost half a million deaths and over 150 million clinical cases each year. An effective vaccine would contribute enormously to malaria control and will almost certainly be required for eventual eradication of the disease. However, the leading malaria vaccine candidate, RTS,S, shows only 30–50% efficacy under field conditions, making it less cost-effective than long-lasting insecticide treated bed nets. Other subunit malaria vaccine candidates, including TRAP-based vaccines, show no better protective efficacy. This has led to increased interest in combining subunit malaria vaccines as a means of enhancing protective efficacy. Mathematical models of the effect of combining such vaccines on protective efficacy can help inform optimal vaccine strategies and decision-making at all stages of the clinical process. So far, however, no such model has been developed for pre-clinical murine studies, the stage at which all candidate antigens and combinations begin evaluation. To address this gap, this paper develops a mathematical model of vaccine combination adapted to murine malaria studies. The model is based on simple probabilistic assumptions which put the model on a firmer theoretical footing than previous clinical models, which rather than deriving a relationship between immune responses and protective efficacy posit the relationship to be either exponential or Hill curves. Data from pre-clinical murine malaria studies are used to derive values for unknowns in the model which in turn allows simulations of vaccine combination efficacy and suggests optimal strategies to pursue. Finally, the ability of the model to shed light on fundamental biological variables of murine malaria such as the blood stage growth rate and sporozoite infectivity is explored.
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41
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Silveira ELV, Dominguez MR, Soares IS. To B or Not to B: Understanding B Cell Responses in the Development of Malaria Infection. Front Immunol 2018; 9:2961. [PMID: 30619319 PMCID: PMC6302011 DOI: 10.3389/fimmu.2018.02961] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 12/03/2018] [Indexed: 12/18/2022] Open
Abstract
Malaria is a widespread disease caused mainly by the Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) protozoan parasites. Depending on the parasite responsible for the infection, high morbidity and mortality can be triggered. To escape the host immune responses, Plasmodium parasites disturb the functionality of B cell subsets among other cell types. However, some antibodies elicited during a malaria infection have the potential to block pathogen invasion and dissemination into the host. Thus, the question remains, why is protection not developed and maintained after the primary parasite exposure? In this review, we discuss different aspects of B cell responses against Plasmodium antigens during malaria infection. Since most studies have focused on the quantification of serum antibody titers, those B cell responses have not been fully characterized. However, to secrete antibodies, a complex cellular response is set up, including not only the activation and differentiation of B cells into antibody-secreting cells, but also the participation of other cell subsets in the germinal center reactions. Therefore, a better understanding of how B cell subsets are stimulated during malaria infection will provide essential insights toward the design of potent interventions.
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Affiliation(s)
- Eduardo L V Silveira
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Mariana R Dominguez
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Irene S Soares
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
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42
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Macintyre F, Ramachandruni H, Burrows JN, Holm R, Thomas A, Möhrle JJ, Duparc S, Hooft van Huijsduijnen R, Greenwood B, Gutteridge WE, Wells TNC, Kaszubska W. Injectable anti-malarials revisited: discovery and development of new agents to protect against malaria. Malar J 2018; 17:402. [PMID: 30384848 PMCID: PMC6211409 DOI: 10.1186/s12936-018-2549-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 10/24/2018] [Indexed: 12/20/2022] Open
Abstract
Over the last 15 years, the majority of malaria drug discovery and development efforts have focused on new molecules and regimens to treat patients with uncomplicated or severe disease. In addition, a number of new molecular scaffolds have been discovered which block the replication of the parasite in the liver, offering the possibility of new tools for oral prophylaxis or chemoprotection, potentially with once-weekly dosing. However, an intervention which requires less frequent administration than this would be a key tool for the control and elimination of malaria. Recent progress in HIV drug discovery has shown that small molecules can be formulated for injections as native molecules or pro-drugs which provide protection for at least 2 months. Advances in antibody engineering offer an alternative approach whereby a single injection could potentially provide protection for several months. Building on earlier profiles for uncomplicated and severe malaria, a target product profile is proposed here for an injectable medicine providing long-term protection from this disease. As with all of such profiles, factors such as efficacy, cost, safety and tolerability are key, but with the changing disease landscape in Africa, new clinical and regulatory approaches are required to develop prophylactic/chemoprotective medicines. An overall framework for these approaches is suggested here.
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Affiliation(s)
- Fiona Macintyre
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Hanu Ramachandruni
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Jeremy N Burrows
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - René Holm
- Drug Product Development, Janssen R&D, Johnson & Johnson, Turnhoutseweg 30, 2340, Beerse, Belgium.,Department of Science and Environment, Roskilde University, 4000, Roskilde, Denmark
| | - Anna Thomas
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Jörg J Möhrle
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | - Stephan Duparc
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
| | | | - Brian Greenwood
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Timothy N C Wells
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland.
| | - Wiweka Kaszubska
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva, Switzerland
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43
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Aliprandini E, Tavares J, Panatieri RH, Thiberge S, Yamamoto MM, Silvie O, Ishino T, Yuda M, Dartevelle S, Traincard F, Boscardin SB, Amino R. Cytotoxic anti-circumsporozoite antibodies target malaria sporozoites in the host skin. Nat Microbiol 2018; 3:1224-1233. [PMID: 30349082 DOI: 10.1038/s41564-018-0254-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 08/28/2018] [Indexed: 01/09/2023]
Abstract
The circumsporozoite protein (CSP) is the major surface protein of malaria sporozoites (SPZs), the motile and invasive parasite stage inoculated in the host skin by infected mosquitoes. Antibodies against the central CSP repeats of different plasmodial species are known to block SPZ infectivity1-5, but the precise mechanism by which these effectors operate is not completely understood. Here, using a rodent Plasmodium yoelii malaria model, we show that sterile protection mediated by anti-P. yoelii CSP humoral immunity depends on the parasite inoculation into the host skin, where antibodies inhibit motility and kill P. yoelii SPZs via a characteristic 'dotty death' phenotype. Passive transfer of an anti-repeat monoclonal antibody (mAb) recapitulates the skin inoculation-dependent protection, in a complement- and Fc receptor γ-independent manner. This purified mAb also decreases motility and, notably, induces the dotty death of P. yoelii SPZs in vitro. Cytotoxicity is species-transcendent since cognate anti-CSP repeat mAbs also kill Plasmodium berghei and Plasmodium falciparum SPZs. mAb cytotoxicity requires the actomyosin motor-dependent translocation and stripping of the protective CSP surface coat, rendering the parasite membrane susceptible to the SPZ pore-forming-like protein secreted to wound and traverse the host cell membrane6. The loss of SPZ fitness caused by anti-P. yoelii CSP repeat antibodies is thus a dynamic process initiated in the host skin where SPZs either stop moving7, or migrate and traverse cells to progress through the host tissues7-9 at the eventual expense of their own life.
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Affiliation(s)
| | - Joana Tavares
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Raquel Hoffmann Panatieri
- Unit of Malaria Infection & Immunity, Institut Pasteur, Paris, France.,Parasitology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sabine Thiberge
- Unit of Malaria Infection & Immunity, Institut Pasteur, Paris, France.,Centre de Production et d'Infection des Anophèles, Institut Pasteur, Paris, France
| | - Marcio Massao Yamamoto
- Parasitology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Olivier Silvie
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, CIMI, Paris, France
| | - Tomoko Ishino
- Department of Molecular Parasitology, Ehime University, Ehime, Japan
| | - Masao Yuda
- Department of Medical Zoology, Mie University School of Medicine, Mie, Japan
| | - Sylvie Dartevelle
- Plateforme d'Ingénierie des Anticorps, Institut Pasteur, Paris, France
| | | | - Silvia Beatriz Boscardin
- Parasitology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Rogerio Amino
- Unit of Malaria Infection & Immunity, Institut Pasteur, Paris, France.
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44
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Cockburn IA, Seder RA. Malaria prevention: from immunological concepts to effective vaccines and protective antibodies. Nat Immunol 2018; 19:1199-1211. [PMID: 30333613 DOI: 10.1038/s41590-018-0228-6] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/31/2018] [Indexed: 02/08/2023]
Abstract
Development of a malaria vaccine remains a critical priority to decrease clinical disease and mortality and facilitate eradication. Accordingly, RTS,S, a protein-subunit vaccine, has completed phase III clinical trials and confers ~30% protection against clinical infection over 4 years. Whole-attenuated-sporozoite and viral-subunit vaccines induce between 20% and 100% protection against controlled human malaria infection, but there is limited published evidence to date for durable, high-level efficacy (>50%) against natural exposure. Importantly, fundamental scientific advances related to the potency, durability, breadth and location of immune responses will be required for improving vaccine efficacy with these and other vaccine approaches. In this Review, we focus on the current understanding of immunological mechanisms of protection from animal models and human vaccine studies, and on how these data should inform the development of next-generation vaccines. Furthermore, we introduce the concept of using passive immunization with monoclonal antibodies as a new approach to prevent and eliminate malaria.
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Affiliation(s)
- Ian A Cockburn
- Department of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Robert A Seder
- Vaccine Research Center, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA.
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45
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Wardemann H, Murugan R. From human antibody structure and function towards the design of a novel Plasmodium falciparum circumsporozoite protein malaria vaccine. Curr Opin Immunol 2018; 53:119-123. [PMID: 29751213 DOI: 10.1016/j.coi.2018.04.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/18/2018] [Accepted: 04/24/2018] [Indexed: 11/19/2022]
Abstract
Malaria is a life-threatening vector-borne disease caused by Plasmodium parasites that infect millions of people in endemic areas every year. The most advanced malaria vaccine candidate RTS,S targets the immune response against circumsporozoite protein of Plasmodium falciparum (PfCSP), the most deadly Plasmodium species in humans. PfCSP plays a fundamental role in parasite development as well as the establishment of the infection and is a molecular target of protective antibodies. However, RTS,S shows overall low efficacy and insufficient long-term protection. Therefore, a major goal in the development of an improved PfCSP-based vaccine remains the reliable and stable induction of protective and ideally sterilizing antibody titers. The molecular and functional characterization of human anti-PfCSP antibody responses paves the way for the rational design of novel immunogens for the development of an improved next-generation PfCSP malaria vaccine.
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Affiliation(s)
- Hedda Wardemann
- German Cancer Research Center, Im Neuenheimer Feld 280, 69121 Heidelberg, Germany.
| | - Rajagopal Murugan
- German Cancer Research Center, Im Neuenheimer Feld 280, 69121 Heidelberg, Germany
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46
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MacRaild CA, Seow J, Das SC, Norton RS. Disordered epitopes as peptide vaccines. Pept Sci (Hoboken) 2018; 110:e24067. [PMID: 32328540 PMCID: PMC7167742 DOI: 10.1002/pep2.24067] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/08/2018] [Accepted: 03/09/2018] [Indexed: 01/23/2023]
Abstract
The development of clinically useful peptide-based vaccines remains a long-standing goal. This review highlights that intrinsically disordered protein antigens, which lack an ordered three-dimensional structure, represent excellent starting points for the development of such vaccines. Disordered proteins represent an important class of antigen in a wide range of human pathogens, and, contrary to widespread belief, they are frequently targets of protective antibody responses. Importantly, disordered epitopes appear invariably to be linear epitopes, rendering them ideally suited to incorporation into a peptide vaccine. Nonetheless, the conformational properties of disordered antigens, and hence their recognition by antibodies, frequently depend on the interactions they make and the context in which they are presented to the immune system. These effects must be considered in the design of an effective vaccine. Here we discuss these issues and propose design principles that may facilitate the development of peptide vaccines targeting disordered antigens.
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Affiliation(s)
- Christopher A. MacRaild
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal ParadeParkville3052Australia
| | - Jeffrey Seow
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal ParadeParkville3052Australia
| | - Sreedam C. Das
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal ParadeParkville3052Australia
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal ParadeParkville3052Australia
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47
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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: 188] [Impact Index Per Article: 31.3] [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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48
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Baay MFD, Richie TL, Neels P. Human challenge trials in vaccine development, Rockville, MD, USA, September 28-30, 2017. Biologicals 2018; 61:85-94. [PMID: 29573967 DOI: 10.1016/j.biologicals.2018.02.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 02/21/2018] [Indexed: 11/17/2022] Open
Abstract
The International Alliance for Biological Standardization organized the second workshop on human challenge trials (HCT) in Rockville, MD, in September 2017. The objective of this meeting was to examine the use of HCT, in response to the continuing human suffering caused by infectious diseases, preventable by the development of new and improved vaccines. For this, the approach of HCT could be valuable, as HCT can provide key safety, tolerability, immunogenicity, and efficacy data, and can be used to study host-pathogen biology. HCT can generate these data with speed, efficiency and minimal expense, albeit not with the same level of robustness as clinical trials. Incorporated wisely into a clinical development plan, HCT can support optimization or down-selection of new vaccine candidates, assuring that only the worthiest candidates progress to field testing. HCT may also provide pivotal efficacy data in support of licensure, particularly when field efficacy studies are not feasible. Many aspects of HCT were discussed by the participants, including new and existing models, standardization and ethics. A consensus was achieved that HCT, if ethically justified and performed with careful attention to safety and informed consent, should be pursued to promote and accelerate vaccine development.
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Affiliation(s)
- Marc F D Baay
- P95 Pharmacovigilance and Epidemiology Services, Leuven, Belgium.
| | - Thomas L Richie
- Sanaria Institute for Global Health and Tropical Medicine, Rockville, MD, USA.
| | - Pieter Neels
- International Alliance for Biological Standardization, Lyon, France.
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49
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A public antibody lineage that potently inhibits malaria infection through dual binding to the circumsporozoite protein. Nat Med 2018; 24:401-407. [PMID: 29554084 PMCID: PMC5893353 DOI: 10.1038/nm.4513] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 02/08/2018] [Indexed: 12/13/2022]
Abstract
Immunization with attenuated Plasmodium falciparum sporozoites (PfSPZs) has been shown to be protective against malaria, but the features of the antibody response induced by this treatment remain unclear. To investigate this response in detail, we isolated IgM and IgG monoclonal antibodies from Tanzanian volunteers who were immunized with repeated injection of Sanaria PfSPZ Vaccine and who were found to be protected from controlled human malaria infection with infectious homologous PfSPZs. All isolated IgG monoclonal antibodies bound to P. falciparum circumsporozoite protein (PfCSP) and recognized distinct epitopes in its N terminus, NANP-repeat region, and C terminus. Strikingly, the most effective antibodies, as determined in a humanized mouse model, bound not only to the repeat region, but also to a minimal peptide at the PfCSP N-terminal junction that is not in the RTS,S vaccine. These dual-specific antibodies were isolated from different donors and were encoded by VH3-30 or VH3-33 alleles that encode tryptophan or arginine at position 52. Using structural and mutational data, we describe the elements required for germline recognition and affinity maturation. Our study provides potent neutralizing antibodies and relevant information for lineage-targeted vaccine design and immunization strategies.
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50
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Prime-boost vaccination with recombinant protein and adenovirus-vector expressing Plasmodium vivax circumsporozoite protein (CSP) partially protects mice against Pb/Pv sporozoite challenge. Sci Rep 2018; 8:1118. [PMID: 29348479 PMCID: PMC5773670 DOI: 10.1038/s41598-017-19063-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 12/21/2017] [Indexed: 12/20/2022] Open
Abstract
Vaccine development against Plasmodium vivax malaria lags behind that for Plasmodium falciparum. To narrow this gap, we administered recombinant antigens based on P. vivax circumsporozoite protein (CSP) to mice. We expressed in Pichia pastoris two chimeric proteins by merging the three central repeat regions of different CSP alleles (VK210, VK247, and P. vivax-like). The first construct (yPvCSP-AllFL) contained the fused repeat regions flanked by N- and C-terminal regions. The second construct (yPvCSP-AllCT) contained the fused repeat regions and the C-terminal domain, plus RI region. Mice were vaccinated with three doses of yPvCSP in adjuvants Poly (I:C) or Montanide ISA720. We also used replication-defective adenovirus vectors expressing CSP of human serotype 5 (AdHu5) and chimpanzee serotype 68 (AdC68) for priming mice which were subsequently boosted twice with yPvCSP proteins in Poly (I:C) adjuvant. Regardless of the regime used, immunized mice generated high IgG titres specific to all CSP alleles. After challenge with P. berghei ANKA transgenic parasites expressing Pb/PvVK210 or Pb/PvVK247 sporozoites, significant time delays for parasitemia were observed in all vaccinated mice. These vaccine formulations should be clinically tried for their potential as protective universal vaccine against P. vivax malaria.
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