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Olewe PK, Awandu SS, Munde EO, Anyona SB, Raballah E, Amolo AS, Ogola S, Ndenga E, Onyango CO, Rochford R, Perkins DJ, Ouma C. Hemoglobinopathies, merozoite surface protein-2 gene polymorphisms, and acquisition of Epstein Barr virus among infants in Western Kenya. BMC Cancer 2023; 23:566. [PMID: 37340364 DOI: 10.1186/s12885-023-11063-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 06/13/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND Epstein Barr virus (EBV)-associated endemic Burkitt's Lymphoma pediatric cancer is associated with morbidity and mortality among children resident in holoendemic Plasmodium falciparum regions in western Kenya. P. falciparum exerts strong selection pressure on sickle cell trait (SCT), alpha thalassemia (-α3.7/αα), glucose-6-phosphate dehydrogenase (G6PD), and merozoite surface protein 2 (MSP-2) variants (FC27, 3D7) that confer reduced malarial disease severity. The current study tested the hypothesis that SCT, (-α3.7/αα), G6PD mutation and (MSP-2) variants (FC27, 3D7) are associated with an early age of EBV acquisition. METHODS Data on infant EBV infection status (< 6 and ≥ 6-12 months of age) was abstracted from a previous longitudinal study. Archived infant DNA (n = 81) and mothers DNA (n = 70) samples were used for genotyping hemoglobinopathies and MSP-2. The presence of MSP-2 genotypes in maternal DNA samples was used to indicate infant in-utero malarial exposure. Genetic variants were determined by TaqMan assays or standard PCR. Group differences were determined by Chi-square or Fisher's analysis. Bivariate regression modeling was used to determine the relationship between the carriage of genetic variants and EBV acquisition. RESULTS EBV acquisition for infants < 6 months was not associated with -α3.7/αα (OR = 1.824, P = 0.354), SCT (OR = 0.897, P = 0.881), or G6PD [Viangchan (871G > A)/Chinese (1024 C > T) (OR = 2.614, P = 0.212)] and [Union (1360 C > T)/Kaiping (1388G > A) (OR = 0.321, P = 0.295)]. There was no relationship between EBV acquisition and in-utero exposure to either FC27 (OR = 0.922, P = 0.914) or 3D7 (OR = 0.933, P = 0.921). In addition, EBV acquisition in infants ≥ 6-12 months also showed no association with -α3.7/αα (OR = 0.681, P = 0.442), SCT (OR = 0.513, P = 0.305), G6PD [(Viangchan (871G > A)/Chinese (1024 C > T) (OR = 0.640, P = 0.677)], [Mahidol (487G > A)/Coimbra (592 C > T) (OR = 0.948, P = 0.940)], [(Union (1360 C > T)/Kaiping (1388G > A) (OR = 1.221, P = 0.768)], African A (OR = 0.278, P = 0.257)], or in utero exposure to either FC27 (OR = 0.780, P = 0.662) or 3D7 (OR = 0.549, P = 0.241). CONCLUSION Although hemoglobinopathies (-α3.7/αα, SCT, and G6PD mutations) and in-utero exposure to MSP-2 were not associated with EBV acquisition in infants 0-12 months, novel G6PD variants were discovered in the population from western Kenya. To establish that the known and novel hemoglobinopathies, and in utero MSP-2 exposure do not confer susceptibility to EBV, future studies with larger sample sizes from multiple sites adopting genome-wide analysis are required.
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Affiliation(s)
- Perez K Olewe
- Department of Biomedical Sciences, School of Health Sciences, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya
- University of New Mexico-Kenyan Global Health Programs Laboratories, Kisumu and Siaya, New Mexico, Kenya
| | - Shehu Shagari Awandu
- Department of Biomedical Sciences, School of Health Sciences, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya
| | - Elly O Munde
- University of New Mexico-Kenyan Global Health Programs Laboratories, Kisumu and Siaya, New Mexico, Kenya
- Department of Clinical Medicine, Kirinyaga University, Kerugoya, Kenya
| | - Samuel B Anyona
- University of New Mexico-Kenyan Global Health Programs Laboratories, Kisumu and Siaya, New Mexico, Kenya
- Department of Medical Biochemistry, School of Medicine, Maseno University, Maseno, Kenya
| | - Evans Raballah
- University of New Mexico-Kenyan Global Health Programs Laboratories, Kisumu and Siaya, New Mexico, Kenya
- Department of Medical Laboratory Sciences, School of Public Health Biomedical Science and Technology, Masinde Muliro University of Science and Technology, Kakamega, Kenya
| | - Asito S Amolo
- Department of Biological Sciences School of Biological, Physical, Mathematics, and Actuarial Sciences, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya
| | - Sidney Ogola
- Kenya Medical Research Institute - CGHR, Kisumu, Kenya
| | - Erick Ndenga
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kenya
| | - Clinton O Onyango
- University of New Mexico-Kenyan Global Health Programs Laboratories, Kisumu and Siaya, New Mexico, Kenya
| | | | - Douglas J Perkins
- University of New Mexico-Kenyan Global Health Programs Laboratories, Kisumu and Siaya, New Mexico, Kenya
- Center for Global Health, Internal Medicine, University of New Mexico, New Mexico, NM, USA
| | - Collins Ouma
- University of New Mexico-Kenyan Global Health Programs Laboratories, Kisumu and Siaya, New Mexico, Kenya.
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kenya.
- Research and Innovations, Maseno University, Kisumu-Busia Road Private Bag, Maseno, Kenya.
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Niaré K, Chege T, Rosenkranz M, Mwai K, Saßmannshausen Z, Odera D, Nyamako L, Tuju J, Alfred T, Waitumbi JN, Ogutu B, Sirima SB, Awandare G, Kouriba B, Rayner JC, Osier FHA. Characterization of a novel Plasmodium falciparum merozoite surface antigen and potential vaccine target. Front Immunol 2023; 14:1156806. [PMID: 37122725 PMCID: PMC10140549 DOI: 10.3389/fimmu.2023.1156806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 03/31/2023] [Indexed: 05/02/2023] Open
Abstract
Introduction Detailed analyses of genetic diversity, antigenic variability, protein localization and immunological responses are vital for the prioritization of novel malaria vaccine candidates. Comprehensive approaches to determine the most appropriate antigen variants needed to provide broad protection are challenging and consequently rarely undertaken. Methods Here, we characterized PF3D7_1136200, which we named Asparagine-Rich Merozoite Antigen (ARMA) based on the analysis of its sequence, localization and immunogenicity. We analyzed IgG and IgM responses against the common variants of ARMA in independent prospective cohort studies in Burkina Faso (N = 228), Kenya (N = 252) and Mali (N = 195) using a custom microarray, Div-KILCHIP. Results We found a marked population structure between parasites from Africa and Asia. African isolates shared 34 common haplotypes, including a dominant pair although the overall selection pressure was directional (Tajima's D = -2.57; Fu and Li's F = -9.69; P < 0.02). ARMA was localized to the merozoite surface, IgG antibodies induced Fc-mediated degranulation of natural killer cells and strongly inhibited parasite growth in vitro. We found profound serological diversity, but IgG and IgM responses were highly correlated and a hierarchical clustering analysis identified only three major serogroups. Protective IgG and IgM antibodies appeared to target both cross-reactive and distinct epitopes across variants. However, combinations of IgG and IgM antibodies against selected variants were associated with complete protection against clinical episodes of malaria. Discussion Our systematic strategy exploits genomic data to deduce the handful of antigen variants with the strongest potential to induce broad protection and may be broadly applicable to other complex pathogens for which effective vaccines remain elusive.
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Affiliation(s)
- Karamoko Niaré
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research—Coast, Kilifi, Kenya
- Malaria Research and Training Centre (MRTC), Department of Epidemiology of Parasitic Diseases, Faculty of Pharmacy, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
- *Correspondence: Karamoko Niaré, ; Faith H. A. Osier,
| | - Timothy Chege
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research—Coast, Kilifi, Kenya
| | - Micha Rosenkranz
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Kennedy Mwai
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research—Coast, Kilifi, Kenya
- Epidemiology and Biostatistics Division, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - Zoe Saßmannshausen
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Dennis Odera
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Lydia Nyamako
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research—Coast, Kilifi, Kenya
| | - James Tuju
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research—Coast, Kilifi, Kenya
| | - Tiono Alfred
- Public Health Department, Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - John N. Waitumbi
- Basic Science Laboratory, US Army Medical Research Directorate-Africa/Kenya Medical Research Institute, Kisumu, Kenya
| | - Bernhards Ogutu
- Kenya Medical Research Institute, Centre for Clinical Research, Nairobi, Kenya
| | | | - Gordon Awandare
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Bourema Kouriba
- Malaria Research and Training Centre (MRTC), Department of Epidemiology of Parasitic Diseases, Faculty of Pharmacy, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
- Centre d’Infectiologie Charles Mérieux-Mali, Bamako, Mali
| | - Julian C. Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Faith H. A. Osier
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research—Coast, Kilifi, Kenya
- Centre for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
- *Correspondence: Karamoko Niaré, ; Faith H. A. Osier,
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Brown SL, Bauer JJ, Lee J, Ntirandekura E, Stumhofer JS. IgM + and IgM - memory B cells represent heterogeneous populations capable of producing class-switched antibodies and germinal center B cells upon rechallenge with P. yoelii. J Leukoc Biol 2022; 112:1115-1135. [PMID: 35657097 PMCID: PMC9613510 DOI: 10.1002/jlb.4a0921-523r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 03/29/2022] [Accepted: 04/15/2022] [Indexed: 12/24/2022] Open
Abstract
Memory B cells (MBCs) are essential for maintaining long-term humoral immunity to infectious organisms, including Plasmodium. MBCs are a heterogeneous population whose function can be dictated by isotype or expression of particular surface proteins. Here, aided by antigen-specific B-cell tetramers, MBC populations were evaluated to discern their phenotype and function in response to infection with a nonlethal strain of P. yoelii. Infection of mice with P. yoelii 17X resulted in 2 predominant MBC populations: somatically hypermutated isotype-switched (IgM- ) and IgM+ MBCs that coexpressed CD73 and CD80 that produced antigen-specific antibodies in response to secondary infection. Rechallenge experiments indicated that IgG-producing cells dominated the recall response over the induction of IgM-secreting cells, with both populations expanding with similar timing during the secondary response. Furthermore, using ZsGreen1 expression as a surrogate for activation-induced cytidine deaminase expression alongside CD73 and CD80 coexpression, ZsGreen1+ CD73+ CD80+ IgM+ , and IgM- MBCs gave rise to plasmablasts that secreted Ag-specific Abs after adoptive transfer and infection with P. yoelii. Moreover, ZsGreen1+ CD73+ CD80+ IgM+ and IgM- MBCs could differentiate into B cells with a germinal center phenotype after adoptive transfer. A third population of B cells (ZsGreen1- CD73- CD80- IgM- ) that is apparent after infection responded poorly to reactivation in vitro and in vivo, indicating that these cells do not represent a canonical population of MBCs. Together these data indicated that MBC function is not defined by immunoglobulin isotype, nor does coexpression of key surface markers limit the potential fate of MBCs after recall.
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Affiliation(s)
- Susie L Brown
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jonathan J Bauer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Juhyung Lee
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Enatha Ntirandekura
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jason S Stumhofer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Jahnmatz P, Nyabundi D, Sundling C, Widman L, Mwacharo J, Musyoki J, Otieno E, Ahlborg N, Bejon P, Ndungu FM, Färnert A. Plasmodium falciparum-Specific Memory B-Cell and Antibody Responses Are Associated With Immunity in Children Living in an Endemic Area of Kenya. Front Immunol 2022; 13:799306. [PMID: 35355994 PMCID: PMC8959630 DOI: 10.3389/fimmu.2022.799306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 02/16/2022] [Indexed: 11/14/2022] Open
Abstract
Identifying the mechanism of naturally acquired immunity against Plasmodium falciparum malaria could contribute to the design of effective malaria vaccines. Using a recently developed multiplexed FluoroSpot assay, we assessed cross-sectional pre-existing memory B-cells (MBCs) and antibody responses against six well known P. falciparum antigens (MSP-119, MSP-2 (3D7), MSP-2 (FC27), MSP-3, AMA-1 and CSP) and measured their associations with previous infections and time to clinical malaria in the ensuing malaria season in Kenyan children. These children were under active weekly surveillance for malaria as part of a long-term longitudinal malaria immunology cohort study, where they are recruited from birth. After performing Cox regression analysis, we found that children with a breadth of three or more antigen-specific MBC or antibody responses at the baseline had a reduced risk for malaria in the ensuing P. falciparum transmission season. Specifically, MBC responses against AMA-1, MSP-2 (3D7) and MSP-3, as well as antibody responses to MSP-2 (3D7) and MSP-3 were prospectively associated with a reduced risk for malaria. The magnitude or breadth of MBC responses were however not correlated with the cumulative number of malaria episodes since birth. We conclude that increased breadth for merozoite antigen-specific MBC and antibody responses is associated with protection against malaria.
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Affiliation(s)
- Peter Jahnmatz
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- Mabtech AB, Nacka Strand, Sweden
| | - Diana Nyabundi
- KEMRI - Wellcome Research Programme/Centre for Geographical Medicine Research (Coast), Kilifi, Kenya
| | - Christopher Sundling
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Linnea Widman
- Division of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Jedidah Mwacharo
- KEMRI - Wellcome Research Programme/Centre for Geographical Medicine Research (Coast), Kilifi, Kenya
| | - Jennifer Musyoki
- KEMRI - Wellcome Research Programme/Centre for Geographical Medicine Research (Coast), Kilifi, Kenya
| | - Edward Otieno
- KEMRI - Wellcome Research Programme/Centre for Geographical Medicine Research (Coast), Kilifi, Kenya
| | - Niklas Ahlborg
- Mabtech AB, Nacka Strand, Sweden
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Philip Bejon
- KEMRI - Wellcome Research Programme/Centre for Geographical Medicine Research (Coast), Kilifi, Kenya
| | - Francis M. Ndungu
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- KEMRI - Wellcome Research Programme/Centre for Geographical Medicine Research (Coast), Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Anna Färnert
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
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Eacret JS, Parzych EM, Gonzales DM, Burns JM. Inclusion of an Optimized Plasmodium falciparum Merozoite Surface Protein 2-Based Antigen in a Trivalent, Multistage Malaria Vaccine. J Immunol 2021; 206:1817-1831. [PMID: 33789984 DOI: 10.4049/jimmunol.2000927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 02/08/2021] [Indexed: 11/19/2022]
Abstract
Plasmodium falciparum merozoite surface protein (PfMSP)2 is a target of parasite-neutralizing Abs. Inclusion of recombinant PfMSP2 (rPfMSP2) as a component of a multivalent malaria vaccine is of interest, but presents challenges. Previously, we used the highly immunogenic PfMSP8 as a carrier to enhance production and/or immunogenicity of malaria vaccine targets. In this study, we exploited the benefits of rPfMSP8 as a carrier to optimize a rPfMSP2-based subunit vaccine. rPfMSP2 and chimeric rPfMSP2/8 vaccines produced in Escherichia coli were evaluated in comparative immunogenicity studies in inbred (CB6F1/J) and outbred (CD1) mice, varying the dose and adjuvant. Immunization of mice with both rPfMSP2-based vaccines elicited high-titer anti-PfMSP2 Abs that recognized the major allelic variants of PfMSP2. Vaccine-induced T cells recognized epitopes present in both PfMSP2 and the PfMSP8 carrier. Competition assays revealed differences in Ab specificities induced by the two rPfMSP2-based vaccines, with evidence of epitope masking by rPfMSP2-associated fibrils. In contrast to aluminum hydroxide (Alum) as adjuvant, formulation of rPfMSP2 vaccines with glucopyranosyl lipid adjuvant-stable emulsion, a synthetic TLR4 agonist, elicited Th1-associated cytokines, shifting production of Abs to cytophilic IgG subclasses. The rPfMSP2/8 + glucopyranosyl lipid adjuvant-stable emulsion formulation induced significantly higher Ab titers with superior durability and capacity to opsonize P. falciparum merozoites for phagocytosis. Immunization with a trivalent vaccine including PfMSP2/8, PfMSP1/8, and the P. falciparum 25 kDa sexual stage antigen fused to PfMSP8 (Pfs25/8) induced high levels of Abs specific for epitopes in each targeted domain, with no evidence of antigenic competition. These results are highly encouraging for the addition of rPfMSP2/8 as a component of an efficacious, multivalent, multistage malaria vaccine.
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Affiliation(s)
- Jacqueline S Eacret
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Elizabeth M Parzych
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Donna M Gonzales
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - James M Burns
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
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Kana IH, Garcia-Senosiain A, Singh SK, Tiendrebeogo RW, Chourasia BK, Malhotra P, Sharma SK, Das MK, Singh S, Adu B, Theisen M. Cytophilic Antibodies Against Key Plasmodium falciparum Blood Stage Antigens Contribute to Protection Against Clinical Malaria in a High Transmission Region of Eastern India. J Infect Dis 2019; 218:956-965. [PMID: 29733355 DOI: 10.1093/infdis/jiy258] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/02/2018] [Indexed: 12/21/2022] Open
Abstract
Background The collection of clinical data from a tribal population in a malaria-endemic area of India suggests the occurrence of naturally acquired immunity (NAI) against Plasmodium falciparum malaria. Methods Quantity and functionality of immunoglobulin G (IgG) antibodies against intact merozoites and recombinant proteins were assessed in a 13-month longitudinal cohort study of 121 individuals, 3-60 years of age. Results Opsonic phagocytosis of merozoites activity was strongly associated (hazard ratio [HR] = 0.34; 95% confidence interval [CI] = .18-.66; P = .0013) with protection against febrile malaria. Of the different IgG subclasses, only IgG3 antibodies against intact whole merozoites was significantly associated with protection against febrile malaria (HR = 0.47; 95% CI = .26-.86; P = .01). Furthermore, a combination of IgG3 antibody responses against Pf12, MSP3.7, MSP3.3, and MSP2FC27 was strongly associated with protection against febrile malaria (HR = 0.15; 95% CI, .06-.37; P = .0001). Conclusions These data suggest that NAI may, at least in part, be explained by opsonic phagocytosis of merozoites and IgG3 responses against whole merozoites, and in particular to a combination of 4 antigens is critical in this population. These results may have implications in the development of a subunit malaria vaccine. Opsonic phagocytosis of Plasmodium falciparum merozoites was associated with protection against clinical malaria in an India population. Antibody profiling identified four merozoite antigens (Pf12, MSP3.7, MSP3.3, and MSP2) as targets of protective Immunoglobuline G3 antibodies.
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Affiliation(s)
- Ikhlaq Hussain Kana
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Asier Garcia-Senosiain
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Susheel K Singh
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Régis Wendpayangde Tiendrebeogo
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Bishwanath Kumar Chourasia
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Pawan Malhotra
- Malaria Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Surya K Sharma
- National Institute of Malaria Research, Indian Council of Medical Research, New Delhi, India
| | - Manoj K Das
- National Institute of Malaria Research, Field Unit, Ranchi (Jharkhand), India
| | - Subhash Singh
- Indian Institute of Integrative Medicine, Canal Road, Jammu, India
| | - Bright Adu
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark
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7
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Eacret JS, Gonzales DM, Franks RG, Burns JM. Immunization with merozoite surface protein 2 fused to a Plasmodium-specific carrier protein elicits strain-specific and strain-transcending, opsonizing antibody. Sci Rep 2019; 9:9022. [PMID: 31227760 PMCID: PMC6588637 DOI: 10.1038/s41598-019-45440-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 06/06/2019] [Indexed: 11/21/2022] Open
Abstract
Vaccine trials and cohort studies in Plasmodium falciparum endemic areas indicate that naturally-acquired and vaccine-induced antibodies to merozoite surface protein 2 (MSP2) are associated with resistance to malaria. These data indicate that PfMSP2 has significant potential as a component of a multi-antigen malaria vaccine. To overcome challenges encountered with subunit malaria vaccines, we established that the use of highly immunogenic rPfMSP8 as a carrier protein for leading vaccine candidates rPfMSP119 and rPfs25 facilitated antigen production, minimized antigenic competition and enhanced induction of functional antibodies. We applied this strategy to optimize a rPfMSP2 (3D7)-based subunit vaccine by producing unfused rPfMSP2 or chimeric rPfMSP2/8 in Escherichia coli. rPfMSP2 formed fibrils, which induced splenocyte proliferation in an antigen receptor-independent, TLR2-dependent manner. However, fusion to rPfMSP8 prevented rPfMSP2 amyloid-like fibril formation. Immunization of rabbits elicited high-titer anti-PfMSP2 antibodies that recognized rPfMSP2 of the 3D7 and FC27 alleles, as well as native PfMSP2. Competition assays revealed a difference in the specificity of antibodies induced by the two rPfMSP2-based vaccines, with evidence of epitope masking by rPfMSP2-associated fibrils. Rabbit anti-PfMSP2/8 was superior to rPfMSP2-elicited antibody at opsonizing P. falciparum merozoites for phagocytosis. These data establish rPfMSP8 as an effective carrier for a PfMSP2-based subunit malaria vaccine.
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Affiliation(s)
- Jacqueline S Eacret
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA
| | - Donna M Gonzales
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA
| | - Raymond G Franks
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA
| | - James M Burns
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA, 19129, USA.
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8
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Chaorattanakawee S, Nuchnoi P, Hananantachai H, Tumkosit U, Saunders D, Naka I, Ohashi J, Patarapotikul J. Sequence variation in Plasmodium falciparum merozoite surface protein-2 is associated with virulence causing severe and cerebral malaria. PLoS One 2018; 13:e0190418. [PMID: 29342212 DOI: 10.1371/journal.pone.0190418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 12/14/2017] [Indexed: 11/20/2022] Open
Abstract
Parasite virulence, an important factor contributing to the severity of Plasmodium falciparum infection, varies among P. falciparum strains. Relatively little is known regarding markers of virulence capable of identifying strains responsible for severe malaria. We investigated the effects of genetic variations in the P.f. merozoite surface protein 2 gene (msp2) on virulence, as it was previously postulated as a factor. We analyzed 300 msp2 sequences of single P. falciparum clone infection from patients with uncomplicated disease as well as those admitted for severe malaria with and without cerebral disease. The association of msp2 variations with disease severity was examined. We found that the N allele at codon 8 of Block 2 in the FC27-like msp2 gene was significantly associated with severe disease without cerebral complications (odds ratio = 2.73, P = 0.039), while the K allele at codon 17 of Block 4 in the 3D7-like msp2 gene was associated with cerebral malaria (odds ratio = 3.52, P = 0.024). The data suggests possible roles for the associated alleles on parasite invasion processes and immune-mediated pathogenicity. Multiplicity of infection was found to associate with severe disease without cerebral complications, but not cerebral malaria. Variations in the msp2-FC27-block 2-8N and 3D7-block 4-17K allele appear to be parasite virulence markers, and may be useful in determining the likelihood for severe and cerebral malaria. Their interactions with potential host factors for severe diseases should also be explored.
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Das SC, Morales RA, Seow J, Krishnarjuna B, Dissanayake R, Anders RF, MacRaild CA, Norton RS. Lipid interactions modulate the structural and antigenic properties of the C-terminal domain of the malaria antigen merozoite surface protein 2. FEBS J 2017; 284:2649-2662. [DOI: 10.1111/febs.14135] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/18/2017] [Accepted: 06/12/2017] [Indexed: 01/06/2023]
Affiliation(s)
- Sreedam C. Das
- Medicinal Chemistry; Monash Institute of Pharmaceutical Sciences; Monash University; Melbourne Australia
| | - Rodrigo A.V. Morales
- Medicinal Chemistry; Monash Institute of Pharmaceutical Sciences; Monash University; Melbourne Australia
| | - Jeffrey Seow
- Medicinal Chemistry; Monash Institute of Pharmaceutical Sciences; Monash University; Melbourne Australia
| | - Bankala Krishnarjuna
- Medicinal Chemistry; Monash Institute of Pharmaceutical Sciences; Monash University; Melbourne Australia
| | - Ravindu Dissanayake
- Department of Biochemistry and Genetics; La Trobe Institute for Molecular Science; La Trobe University; Melbourne Australia
| | - Robin F. Anders
- Department of Biochemistry and Genetics; La Trobe Institute for Molecular Science; La Trobe University; Melbourne Australia
| | - Christopher A. MacRaild
- Medicinal Chemistry; Monash Institute of Pharmaceutical Sciences; Monash University; Melbourne Australia
| | - Raymond S. Norton
- Medicinal Chemistry; Monash Institute of Pharmaceutical Sciences; Monash University; Melbourne Australia
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Murungi LM, Sondén K, Llewellyn D, Rono J, Guleid F, Williams AR, Ogada E, Thairu A, Färnert A, Marsh K, Draper SJ, Osier FHA. Targets and Mechanisms Associated with Protection from Severe Plasmodium falciparum Malaria in Kenyan Children. Infect Immun 2016; 84:950-963. [PMID: 26787721 PMCID: PMC4807498 DOI: 10.1128/iai.01120-15] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 01/14/2016] [Indexed: 01/23/2023] Open
Abstract
Severe malaria (SM) is a life-threatening complication of infection with Plasmodium falciparum Epidemiological observations have long indicated that immunity against SM is acquired relatively rapidly, but prospective studies to investigate its immunological basis are logistically challenging and have rarely been undertaken. We investigated the merozoite targets and antibody-mediated mechanisms associated with protection against SM in Kenyan children aged 0 to 2 years. We designed a unique prospective matched case-control study of well-characterized SM clinical phenotypes nested within a longitudinal birth cohort of children (n= 5,949) monitored over the first 2 years of life. We quantified immunological parameters in sera collected before the SM event in cases and their individually matched controls to evaluate the prospective odds of developing SM in the first 2 years of life. Anti-AMA1 antibodies were associated with a significant reduction in the odds of developing SM (odds ratio [OR] = 0.37; 95% confidence interval [CI] = 0.15 to 0.90; P= 0.029) after adjustment for responses to all other merozoite antigens tested, while those against MSP-2, MSP-3, Plasmodium falciparum Rh2 [PfRh2], MSP-119, and the infected red blood cell surface antigens were not. The combined ability of total IgG to inhibit parasite growth and mediate the release of reactive oxygen species from neutrophils was associated with a marked reduction in the odds of developing SM (OR = 0.07; 95% CI = 0.006 to 0.82;P= 0.03). Assays of these two functional mechanisms were poorly correlated (Spearman rank correlation coefficient [rs] = 0.12;P= 0.07). Our data provide epidemiological evidence that multiple antibody-dependent mechanisms contribute to protective immunity via distinct targets whose identification could accelerate the development of vaccines to protect against SM.
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Affiliation(s)
- Linda M Murungi
- KEMRI Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya
| | - Klara Sondén
- Unit of Infectious Diseases, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
| | - David Llewellyn
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Josea Rono
- KEMRI Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya
| | - Fatuma Guleid
- KEMRI Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya
| | | | - Edna Ogada
- KEMRI Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya
| | - Amos Thairu
- KEMRI Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya
| | - Anna Färnert
- Unit of Infectious Diseases, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
| | - Kevin Marsh
- KEMRI Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya
- Nuffield Department of Medicine, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - Simon J Draper
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Faith H A Osier
- KEMRI Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya
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11
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Osier FH, Mackinnon MJ, Crosnier C, Fegan G, Kamuyu G, Wanaguru M, Ogada E, McDade B, Rayner JC, Wright GJ, Marsh K. New antigens for a multicomponent blood-stage malaria vaccine. Sci Transl Med 2015; 6:247ra102. [PMID: 25080477 DOI: 10.1126/scitranslmed.3008705] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
An effective blood-stage vaccine against Plasmodium falciparum remains a research priority, but the number of antigens that have been translated into multicomponent vaccines for testing in clinical trials remains limited. Investigating the large number of potential targets found in the parasite proteome has been constrained by an inability to produce natively folded recombinant antigens for immunological studies. We overcame these constraints by generating a large library of biochemically active merozoite surface and secreted full-length ectodomain proteins. We then systematically examined the antibody reactivity against these proteins in a cohort of Kenyan children (n = 286) who were sampled at the start of a malaria transmission season and prospectively monitored for clinical episodes of malaria over the ensuing 6 months. We found that antibodies to previously untested or little-studied proteins had superior or equivalent potential protective efficacy to the handful of current leading malaria vaccine candidates. Moreover, cumulative responses to combinations comprising 5 of the 10 top-ranked antigens, including PF3D7_1136200, MSP2, RhopH3, P41, MSP11, MSP3, PF3D7_0606800, AMA1, Pf113, and MSRP1, were associated with 100% protection against clinical episodes of malaria. These data suggest not only that there are many more potential antigen candidates for the malaria vaccine development pipeline but also that effective vaccination may be achieved by combining a selection of these antigens.
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Affiliation(s)
- Faith H Osier
- Pathogen Vector and Human Biology Department, Kenya Medical Research Institute Centre for Geographical Medicine Research, Coast, P. O. Box 230, 80108 Kilifi, Kenya
| | - Margaret J Mackinnon
- Pathogen Vector and Human Biology Department, Kenya Medical Research Institute Centre for Geographical Medicine Research, Coast, P. O. Box 230, 80108 Kilifi, Kenya
| | - Cécile Crosnier
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1HH, UK. Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, UK
| | - Gregory Fegan
- Pathogen Vector and Human Biology Department, Kenya Medical Research Institute Centre for Geographical Medicine Research, Coast, P. O. Box 230, 80108 Kilifi, Kenya
| | - Gathoni Kamuyu
- Pathogen Vector and Human Biology Department, Kenya Medical Research Institute Centre for Geographical Medicine Research, Coast, P. O. Box 230, 80108 Kilifi, Kenya
| | - Madushi Wanaguru
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1HH, UK. Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, UK
| | - Edna Ogada
- Pathogen Vector and Human Biology Department, Kenya Medical Research Institute Centre for Geographical Medicine Research, Coast, P. O. Box 230, 80108 Kilifi, Kenya
| | - Brian McDade
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1HH, UK
| | - Julian C Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, UK
| | - Gavin J Wright
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Cambridge CB10 1HH, UK. Malaria Programme, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, UK
| | - Kevin Marsh
- Pathogen Vector and Human Biology Department, Kenya Medical Research Institute Centre for Geographical Medicine Research, Coast, P. O. Box 230, 80108 Kilifi, Kenya.
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Rono J, Färnert A, Murungi L, Ojal J, Kamuyu G, Guleid F, Nyangweso G, Wambua J, Kitsao B, Olotu A, Marsh K, Osier FH. Multiple clinical episodes of Plasmodium falciparum malaria in a low transmission intensity setting: exposure versus immunity. BMC Med 2015; 13:114. [PMID: 25967134 PMCID: PMC4445794 DOI: 10.1186/s12916-015-0354-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 04/27/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Epidemiological studies indicate that some children experience many more episodes of clinical malaria than their age mates in a given location. Whether this is as a result of the micro-heterogeneity of malaria transmission with some children effectively getting more exposure to infectious mosquitoes than others, or reflects a failure in the acquisition of immunity needs to be elucidated. Here, we investigated the determinants of increased susceptibility to clinical malaria by comparing the intensity of exposure to Plasmodium falciparum and the acquisition of immunity in children at the extreme ends of the over-dispersed distribution of the incidence of clinical malaria. METHODS The study was nested within a larger cohort in an area where the intensity of malaria transmission was low. We identified children who over a five-year period experienced 5 to 16 clinical malaria episodes (children at the tail-end of the over-dispersed distribution, n = 35), remained malaria-free (n = 12) or had a single episode (n = 26). We quantified antibodies against seven Plasmodium falciparum merozoite antigens in plasma obtained at six cross-sectional surveys spanning these five years. We analyzed the antibody responses to identify temporal dynamics that associate with disease susceptibility. RESULTS Children experiencing multiple episodes of malaria were more likely to be parasite positive by microscopy at cross-sectional surveys (X (2) test for trend 14.72 P = 0.001) and had a significantly higher malaria exposure index, than those in the malaria-free or single episode groups (Kruskal-Wallis test P = 0.009). In contrast, the five-year temporal dynamics of anti-merozoite antibodies were similar in the three groups. Importantly in all groups, antibody levels were below the threshold concentrations previously observed to be correlated with protective immunity. CONCLUSIONS We conclude that in the context of a low malaria transmission setting, susceptibility to clinical malaria is not accounted for by anti-merozoite antibodies but appears to be a consequence of increased parasite exposure. We hypothesize that intensive exposure is a prerequisite for protective antibody concentrations, while little to modest exposure may manifest as multiple clinical infections with low levels of antibodies. These findings have implications for interventions that effectively lower malaria transmission intensity.
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Affiliation(s)
- Josea Rono
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya. .,Infectious Diseases Unit, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden.
| | - Anna Färnert
- Infectious Diseases Unit, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden.
| | - Linda Murungi
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
| | - John Ojal
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
| | - Gathoni Kamuyu
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
| | - Fatuma Guleid
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
| | - George Nyangweso
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
| | - Juliana Wambua
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
| | - Barnes Kitsao
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
| | - Ally Olotu
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
| | - Kevin Marsh
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya. .,Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, UK.
| | - Faith Ha Osier
- KEMRI-Wellcome Trust Research Programme, Centre for Geographical Medicine Research-Coast, Kilifi, Kenya.
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MacRaild CA, Zachrdla M, Andrew D, Krishnarjuna B, Nováček J, Žídek L, Sklenář V, Richards JS, Beeson JG, Anders RF, Norton RS. Conformational dynamics and antigenicity in the disordered malaria antigen merozoite surface protein 2. PLoS One 2015; 10:e0119899. [PMID: 25742002 PMCID: PMC4351039 DOI: 10.1371/journal.pone.0119899] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/16/2015] [Indexed: 12/14/2022] Open
Abstract
Merozoite surface protein 2 (MSP2) of Plasmodium falciparum is an abundant, intrinsically disordered protein that is GPI-anchored to the surface of the invasive blood stage of the malaria parasite. Recombinant MSP2 has been trialled as a component of a malaria vaccine, and is one of several disordered proteins that are candidates for inclusion in vaccines for malaria and other diseases. Nonetheless, little is known about the implications of protein disorder for the development of an effective antibody response. We have therefore undertaken a detailed analysis of the conformational dynamics of the two allelic forms of MSP2 (3D7 and FC27) using NMR spectroscopy. Chemical shifts and NMR relaxation data indicate that conformational and dynamic properties of the N- and C-terminal conserved regions in the two forms of MSP2 are essentially identical, but significant variation exists between and within the central variable regions. We observe a strong relationship between the conformational dynamics and the antigenicity of MSP2, as assessed with antisera to recombinant MSP2. Regions of increased conformational order in MSP2, including those in the conserved regions, are more strongly antigenic, while the most flexible regions are minimally antigenic. This suggests that modifications that increase conformational order may offer a means to tune the antigenicity of MSP2 and other disordered antigens, with implications for vaccine design.
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Affiliation(s)
- Christopher A. MacRaild
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, 3052, Australia
- * E-mail:
| | - Milan Zachrdla
- NCBR, Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- CEITEC, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - Dean Andrew
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, 3004, Australia
| | - Bankala Krishnarjuna
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, 3052, Australia
| | - Jiří Nováček
- NCBR, Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- CEITEC, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - Lukáš Žídek
- NCBR, Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- CEITEC, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - Vladimír Sklenář
- NCBR, Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- CEITEC, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - Jack S. Richards
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, 3004, Australia
| | - James G. Beeson
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, 3004, Australia
| | - Robin F. Anders
- Department of Biochemistry, La Trobe University, Victoria, 3086, Australia
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, 3052, Australia
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Balam S, Olugbile S, Servis C, Diakité M, D'Alessandro A, Frank G, Moret R, Nebie I, Tanner M, Felger I, Smith T, Kajava AV, Spertini F, Corradin G. Plasmodium falciparum merozoite surface protein 2: epitope mapping and fine specificity of human antibody response against non-polymorphic domains. Malar J 2014; 13:510. [PMID: 25526742 PMCID: PMC4320585 DOI: 10.1186/1475-2875-13-510] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 12/06/2014] [Indexed: 11/16/2022] Open
Abstract
Background Two long synthetic peptides representing the dimorphic and constant C-terminal domains of the two allelic families of Plasmodium falciparum merozoite surface proteins 2 are considered promising malaria vaccine candidates. The aim of the current study is to characterize the immune response (epitope mapping) in naturally exposed individuals and relate immune responses to the risk of clinical malaria. Methods To optimize their construction, the fine specificity of human serum antibodies from donors of different age, sex and living in four distinct endemic regions was determined in ELISA by using overlapping 20 mer peptides covering the two domains. Immune purified antibodies were used in Western blot and immunofluorescence assay to recognize native parasite derivate proteins. Results Immunodominant epitopes were characterized, and their distribution was similar irrespective of geographic origin, age group and gender. Acquisition of a 3D7 family and constant region-specific immune response and antibody avidity maturation occur early in life while a longer period is needed for the corresponding FC27 family response. In addition, the antibody response to individual epitopes within the 3D7 family-specific region contributes to protection from malaria infection with different statistical weight. It is also illustrated that affinity-purified antibodies against the dimorphic or constant regions recognized homologous and heterologous parasites in immunofluorescence and homologous and heterologous MSP2 and other polypeptides in Western blot. Conclusion Data from this current study may contribute to a development of MSP2 vaccine candidates based on conserved and dimorphic regions thus bypassing the complexity of vaccine development related to the polymorphism of full-length MSP2. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-510) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Saidou Balam
- Department of Biochemistry, University of Lausanne, Ch des Boveresses 155, 1066 Epalinges, Switzerland.
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15
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Perraut R, Richard V, Varela ML, Trape JF, Guillotte M, Tall A, Toure A, Sokhna C, Vigan-Womas I, Mercereau-Puijalon O. Comparative analysis of IgG responses to Plasmodium falciparum MSP1p19 and PF13-DBL1α1 using ELISA and a magnetic bead-based duplex assay (MAGPIX®-Luminex) in a Senegalese meso-endemic community. Malar J 2014; 13:410. [PMID: 25326042 PMCID: PMC4221706 DOI: 10.1186/1475-2875-13-410] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/09/2014] [Indexed: 01/16/2023] Open
Abstract
Background Numerous Plasmodium falciparum antigens elicit humoral responses in humans living in endemic areas. Use of multiplex assays is a convenient approach to monitor the antibody response against multiple antigens, but to integrate multiplex assay-derived data with datasets, generated previously using ELISA, comparative studies are needed. This work compares antibody responses to two P. falciparum antigens monitored using both technologies. Methods The IgG response against the merozoite surface protein-1 PfMSP1p19 and the PF13-DBL1α1 domain of the P. falciparum Erythrocyte Membrane Protein1, expressed by the rosette-forming parasite 3D7/PF13 (PF13), was investigated using ELISA and a MAGPIX®-Luminex duplex assay. Archived plasma samples collected before the rainy season from 217 villagers living in Ndiop, a Senegalese meso-endemic setting, were studied. ROC analysis was used to define the optimal antibody measure readout. Association of antibody levels with protection against clinical malaria was analysed using Poisson regression in a retrospective study from active case detection records performed during the 5.5-month transmission season that followed blood sampling. Results There was a strong positive correlation (P <10-3) between ELISA and MAGPIX®-Luminex-MFI (median fluorescence intensity) values for antibody to PfMSP1p19 (rho = 0.78) and PF13-DBL1α1 (rho = 0.89), with a similar degree of concordance in all age groups. Antibody levels to both antigens were high but displayed a different age-associated pattern. Independent age-adjusted Poisson regression analysis showed a significant association with protection only for IgG responses to MSP1p19 (P <0.01 RR = 0.71 [0.53-0.93]) measured by ELISA. Conclusion The individual ELISA and duplex-MAGPIX assays provide a concordant evaluation of age-associated antibody responses to MSP1p19 and PF13-DBL1α1, irrespective of the formulation of antibody levels (values, ratios or ROC-adjusted figures) but do diverge with regard to the association of antibody levels with clinical protection in age-adjusted models. This may reflect incomplete overlap of the epitopes presented in the two formats. Further development for multiplex assessment of antibody responses to a larger panel of antigens with the robust and cost effective MAGPIX®-Luminex technology is warranted. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-410) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ronald Perraut
- Institut Pasteur de Dakar, Unité d'Immunologie, Dakar, Sénégal.
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16
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Medeiros MM, Fotoran WL, dalla Martha RC, Katsuragawa TH, Pereira da Silva LH, Wunderlich G. Natural antibody response to Plasmodium falciparum merozoite antigens MSP5, MSP9 and EBA175 is associated to clinical protection in the Brazilian Amazon. BMC Infect Dis 2013; 13:608. [PMID: 24373342 PMCID: PMC3880555 DOI: 10.1186/1471-2334-13-608] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 12/23/2013] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Antibodies have an essential role in the acquired immune response against blood stage P. falciparum infection. Although several antigens have been identified as important antibody targets, it is still elusive which antigens have to be recognized for clinical protection. Herein, we analyzed antibodies from plasmas from symptomatic or asymptomatic individuals living in the same geographic area in the Western Amazon, measuring their recognition of multiple merozoite antigens. METHODS Specific fragments of genes encoding merozoite proteins AMA1 and members of MSP and EBL families from circulating P. falciparum field isolates present in asymptomatic and symptomatic patients were amplified by PCR. After cloning and expression of different versions of the antigens as recombinant GST-fusion peptides, we tested the reactivity of patients' plasmas by ELISA and the presence of IgG subclasses in the most reactive plasmas. RESULTS 11 out of 24 recombinant antigens were recognized by plasmas from either symptomatic or asymptomatic infections. Antibodies to MSP9 (X2(DF=1) = 9.26/p = 0.0047) and MSP5 (X2(DF=1) = 8.29/p = 0.0069) were more prevalent in asymptomatic individuals whereas the opposite was observed for MSP1 block 2-MAD20 (X2(DF=1) = 6.41/p = 0.0206, Fisher's exact test). Plasmas from asymptomatic individuals reacted more intensely against MSP4 (U = 210.5, p < 0.03), MSP5 (U = 212, p < 0.004), MSP9 (U = 189.5, p < 0.002) and EBA175 (U = 197, p < 0.014, Mann-Whitney's U test). IgG1 and IgG3 were predominant for all antigens, but some patients also presented with IgG2 and IgG4. The recognition of MSP5 (OR = 0.112, IC95% = 0.021-0.585) and MSP9 (OR = 0.125, IC95% = 0.030-0.529, cross tab analysis) predicted 8.9 and 8 times less chances, respectively, to present symptoms. Higher antibody levels against MSP5 and EBA175 were associated by odds ratios of 9.4 (IC95% = 1.29-69.25) and 5.7 (IC95% = 1.12-29.62, logistic regression), respectively, with an asymptomatic status. CONCLUSIONS Merozoite antigens were targets of cytophilic antibodies and antibodies against MSP5, MSP9 and EBA175 were independently associated with decreased symptoms.
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Affiliation(s)
| | | | | | | | | | - Gerhard Wunderlich
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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17
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Murungi LM, Kamuyu G, Lowe B, Bejon P, Theisen M, Kinyanjui SM, Marsh K, Osier FHA. A threshold concentration of anti-merozoite antibodies is required for protection from clinical episodes of malaria. Vaccine 2013; 31:3936-42. [PMID: 23800539 PMCID: PMC3763364 DOI: 10.1016/j.vaccine.2013.06.042] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 05/14/2013] [Accepted: 06/12/2013] [Indexed: 11/03/2022]
Abstract
Antibodies to selected Plasmodium falciparum merozoite antigens are often reported to be associated with protection from malaria in one epidemiological cohort, but not in another. Here, we sought to understand this paradox by exploring the hypothesis that a threshold concentration of antibodies is necessary for protection. We analyzed data from two independent cohorts along the Kenyan coast, one in which antibodies to AMA1, MSP-2 and MSP-3 were associated with protection from malaria (Chonyi) and another in which this association was not observed (Junju). We used a malaria reference reagent to standardize antibody measurements across both cohorts, and applied statistical methods to derive the threshold concentration of antibodies against each antigen that best correlated with a reduced risk of malaria (the protective threshold), in the Chonyi cohort. We then tested whether antibodies in Junju reached the protective threshold concentrations observed in the Chonyi cohort. Except for children under 3 years, the age-matched proportions of children achieving protective threshold concentrations of antibodies against AMA1 and MSP-2 were significantly lower in Junju compared to Chonyi (Fishers exact test, P<0.01). For MSP-3, this difference was significant only among 4-5 year olds. We conclude that although antibodies are commonly detected in malaria endemic populations, they may be present in concentrations that are insufficient for protection. Our results have implications for the analysis and interpretation of similar data from immuno-epidemiological studies.
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Affiliation(s)
- Linda M Murungi
- KEMRI Centre for Geographic Medicine Research, Coast, P.O. Box 230-80108, Kilifi, Kenya.
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Lundblom K, Murungi L, Nyaga V, Olsson D, Rono J, Osier F, Ogada E, Montgomery S, Scott JAG, Marsh K, Färnert A. Plasmodium falciparum infection patterns since birth and risk of severe malaria: a nested case-control study in children on the coast of Kenya. PLoS One 2013; 8:e56032. [PMID: 23418502 PMCID: PMC3572150 DOI: 10.1371/journal.pone.0056032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 01/04/2013] [Indexed: 01/27/2023] Open
Abstract
Children in malaria endemic areas acquire immunity to severe malaria faster than to mild malaria. Only a minority of children suffers from severe malaria and it is not known what determines this. The aim of this study was to establish how P. falciparum infections during the first years of life affect the risk of severe malaria. A matched case-control study was nested within a large birth cohort set up to study the immunoepidemiology of pneumococci on the Kenyan coast. Infection patterns in three-monthly blood samples in cohort children admitted to hospital with severe malaria were compared to controls matched on age, residential location and time of sampling. P. falciparum detected at least once from birth conferred an increased risk of severe malaria and particularly if multiclonal infections, as characterized by genotyping of a polymorphic antigen gene, were ever detected. The results show for the first time that children with severe malaria have more infections early in life compared to community controls. These findings provide important insights on the immunity to severe disease, knowledge essential for the development of a vaccine against severe malaria.
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Affiliation(s)
- Klara Lundblom
- Unit of Infectious Diseases, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden.
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Adda CG, MacRaild CA, Reiling L, Wycherley K, Boyle MJ, Kienzle V, Masendycz P, Foley M, Beeson JG, Norton RS, Anders RF. Antigenic characterization of an intrinsically unstructured protein, Plasmodium falciparum merozoite surface protein 2. Infect Immun 2012; 80:4177-85. [PMID: 22966050 DOI: 10.1128/IAI.00665-12] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Merozoite surface protein 2 (MSP2) is an abundant glycosylphosphatidylinositol (GPI)-anchored protein of Plasmodium falciparum, which is a potential component of a malaria vaccine. As all forms of MSP2 can be categorized into two allelic families, a vaccine containing two representative forms of MSP2 may overcome the problem of diversity in this highly polymorphic protein. Monomeric recombinant MSP2 is an intrinsically unstructured protein, but its conformational properties on the merozoite surface are unknown. This question is addressed here by analyzing the 3D7 and FC27 forms of recombinant and parasite MSP2 using a panel of monoclonal antibodies raised against recombinant MSP2. The epitopes of all antibodies, mapped using both a peptide array and by nuclear magnetic resonance (NMR) spectroscopy on full-length recombinant MSP2, were shown to be linear. The antibodies revealed antigenic differences, which indicate that the conserved N- and C-terminal regions, but not the central variable region, are less accessible in the parasite antigen. This appears to be an intrinsic property of parasite MSP2 and is not dependent on interactions with other merozoite surface proteins as the loss of some conserved-region epitopes seen using the immunofluorescence assay (IFA) on parasite smears was also seen on Western blot analyses of parasite lysates. Further studies of the structural basis of these antigenic differences are required in order to optimize recombinant MSP2 constructs being evaluated as potential vaccine components.
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Weedall GD, Clark CG, Koldkjaer P, Kay S, Bruchhaus I, Tannich E, Paterson S, Hall N. Genomic diversity of the human intestinal parasite Entamoeba histolytica. Genome Biol 2012; 13:R38. [PMID: 22630046 PMCID: PMC3446291 DOI: 10.1186/gb-2012-13-5-r38] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 04/29/2012] [Accepted: 05/25/2012] [Indexed: 11/10/2022] Open
Abstract
Background Results Conclusions
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McCarthy JS, Marjason J, Elliott S, Fahey P, Bang G, Malkin E, Tierney E, Aked-Hurditch H, Adda C, Cross N, Richards JS, Fowkes FJ, Boyle MJ, Long C, Druilhe P, Beeson JG, Anders RF. A phase 1 trial of MSP2-C1, a blood-stage malaria vaccine containing 2 isoforms of MSP2 formulated with Montanide® ISA 720. PLoS One 2011; 6:e24413. [PMID: 21949716 DOI: 10.1371/journal.pone.0024413] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 08/10/2011] [Indexed: 11/19/2022] Open
Abstract
Background In a previous Phase 1/2b malaria vaccine trial testing the 3D7 isoform of the malaria vaccine candidate Merozoite surface protein 2 (MSP2), parasite densities in children were reduced by 62%. However, breakthrough parasitemias were disproportionately of the alternate dimorphic form of MSP2, the FC27 genotype. We therefore undertook a dose-escalating, double-blinded, placebo-controlled Phase 1 trial in healthy, malaria-naïve adults of MSP2-C1, a vaccine containing recombinant forms of the two families of msp2 alleles, 3D7 and FC27 (EcMSP2-3D7 and EcMSP2-FC27), formulated in equal amounts with Montanide® ISA 720 as a water-in-oil emulsion. Methodology/Principal Findings The trial was designed to include three dose cohorts (10, 40, and 80 µg), each with twelve subjects receiving the vaccine and three control subjects receiving Montanide® ISA 720 adjuvant emulsion alone, in a schedule of three doses at 12-week intervals. Due to unexpected local reactogenicity and concern regarding vaccine stability, the trial was terminated after the second immunisation of the cohort receiving the 40 µg dose; no subjects received the 80 µg dose. Immunization induced significant IgG responses to both isoforms of MSP2 in the 10 µg and 40 µg dose cohorts, with antibody levels by ELISA higher in the 40 µg cohort. Vaccine-induced antibodies recognised native protein by Western blots of parasite protein extracts and by immunofluorescence microscopy. Although the induced anti-MSP2 antibodies did not directly inhibit parasite growth in vitro, IgG from the majority of individuals tested caused significant antibody-dependent cellular inhibition (ADCI) of parasite growth. Conclusions/Significance As the majority of subjects vaccinated with MSP2-C1 developed an antibody responses to both forms of MSP2, and that these antibodies mediated ADCI provide further support for MSP2 as a malaria vaccine candidate. However, in view of the reactogenicity of this formulation, further clinical development of MSP2-C1 will require formulation of MSP2 in an alternative adjuvant. Trial Registration Australian New Zealand Clinical Trials Registry 12607000552482
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Miller MR, Råberg L, Read AF, Savill NJ. Quantitative analysis of immune response and erythropoiesis during rodent malarial infection. PLoS Comput Biol 2010; 6:e1000946. [PMID: 20941388 PMCID: PMC2947982 DOI: 10.1371/journal.pcbi.1000946] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Accepted: 08/31/2010] [Indexed: 12/20/2022] Open
Abstract
Malarial infection is associated with complex immune and erythropoietic responses in the host. A quantitative understanding of these processes is essential to help inform malaria therapy and for the design of effective vaccines. In this study, we use a statistical model-fitting approach to investigate the immune and erythropoietic responses in Plasmodium chabaudi infections of mice. Three mouse phenotypes (wildtype, T-cell-deficient nude mice, and nude mice reconstituted with T-cells taken from wildtype mice) were infected with one of two parasite clones (AS or AJ). Under a Bayesian framework, we use an adaptive population-based Markov chain Monte Carlo method and fit a set of dynamical models to observed data on parasite and red blood cell (RBC) densities. Model fits are compared using Bayes' factors and parameter estimates obtained. We consider three independent immune mechanisms: clearance of parasitised RBCs (pRBC), clearance of unparasitised RBCs (uRBC), and clearance of parasites that burst from RBCs (merozoites). Our results suggest that the immune response of wildtype mice is associated with less destruction of uRBCs, compared to the immune response of nude mice. There is a greater degree of synchronisation between pRBC and uRBC clearance than between either mechanism and merozoite clearance. In all three mouse phenotypes, control of the peak of parasite density is associated with pRBC clearance. In wildtype mice and AS-infected nude mice, control of the peak is also associated with uRBC clearance. Our results suggest that uRBC clearance, rather than RBC infection, is the major determinant of RBC dynamics from approximately day 12 post-innoculation. During the first 2-3 weeks of blood-stage infection, immune-mediated clearance of pRBCs and uRBCs appears to have a much stronger effect than immune-mediated merozoite clearance. Upregulation of erythropoiesis is dependent on mouse phenotype and is greater in wildtype and reconstitited mice. Our study highlights the informative power of statistically rigorous model-fitting techniques in elucidating biological systems.
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Affiliation(s)
- Martin R. Miller
- Centre for Infectious Diseases, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Lars Råberg
- Department of Animal Ecology, Lund University, Lund, Sweden
| | - Andrew F. Read
- Center for Infectious Disease Dynamics and Departments of Biology and Entomology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Nicholas J. Savill
- Centre for Infectious Diseases, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
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