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Bunkofske ME, Perumal N, White B, Strauch EM, Tarleton R. Epitopes in the Glycosylphosphatidylinositol Attachment Signal Peptide of Trypanosoma cruzi Mucin Proteins Generate Robust but Delayed and Nonprotective CD8+ T Cell Responses. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 210:420-430. [PMID: 36603035 PMCID: PMC9898211 DOI: 10.4049/jimmunol.2200723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/05/2022] [Indexed: 01/06/2023]
Abstract
Infection with the protozoan parasite Trypanosoma cruzi elicits substantial CD8+ T cell responses that disproportionately target epitopes encoded in the large trans-sialidase (TS) gene family. Within the C57BL/6 infection model, a significant proportion (30-40%) of the T. cruzi-specific CD8+ T cell response targets two immunodominant TS epitopes, TSKb18 and TSKb20. However, both TS-specific CD8+ T cell responses are dispensable for immune control, and TS-based vaccines have no demonstrable impact on parasite persistence, a determinant of disease. Besides TS, the specificity and protective capacity of CD8+ T cells that mediate immune control of T. cruzi infection are unknown. With the goal of identifying alternative CD8+ T cell targets, we designed and screened a representative set of genome-wide, in silico-predicted epitopes. Our screen identified a previously uncharacterized, to our knowledge, T cell epitope MUCKb25, found within mucin family proteins, the third most expanded large gene family in T. cruzi. The MUCKb25-specific response was characterized by delayed kinetics, relative to TS-specific responses, and extensive cross-reactivity with a large number of endogenous epitope variants. Similar to TS-specific responses, the MUCKb25 response was dispensable for control of the infection, and vaccination to generate MUCK-specific CD8+ T cells failed to confer protection. The lack of protection by MUCK vaccination was partly attributed to the fact that MUCKb25-specific T cells exhibit limited recognition of T. cruzi-infected host cells. Overall, these results indicate that the CD8+ T cell compartment in many T. cruzi-infected mice is occupied by cells with minimal apparent effector potential.
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Affiliation(s)
- Molly E. Bunkofske
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Natasha Perumal
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Brooke White
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Eva-Maria Strauch
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, USA
| | - Rick Tarleton
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
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Belmonte M, Ganeshan H, Huang J, Belmonte A, Inoue S, Velasco R, Acheampong N, Ofori EA, Akyea-Mensah K, Frimpong A, Ennuson NA, Frempong AF, Kyei-Baafour E, Amoah LE, Edgel K, Peters B, Villasante E, Kusi KA, Sedegah M. Immunodominant T cell peptides from four candidate malarial antigens as biomarkers of protective immunity against malaria. Vaccine 2023; 41:1265-1273. [PMID: 36642628 DOI: 10.1016/j.vaccine.2023.01.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 01/05/2023] [Accepted: 01/07/2023] [Indexed: 01/15/2023]
Abstract
A malaria vaccine with high efficacy and capable of inducing sterile immunity against malaria within genetically diverse populations is urgently needed to complement ongoing disease control and elimination efforts. Parasite-specific IFN-γ and granzyme B-secreting CD8 + T cells have been identified as key mediators of protection and the rapid identification of malaria antigen targets that elicit these responses will fast-track the development of simpler, cost-effective interventions. This study extends our previous work which used peripheral blood mononuclear cells (PBMCs) from adults with life-long exposure to malaria parasites to identify immunodominant antigen-specific peptide pools composed of overlapping 15mer sequences spanning full length proteins of four malarial antigens. Our current study aimed to identify CD8 + T cell epitopes within these previously identified positive peptide pools. Cryopreserved PBMCs from 109 HLA-typed subjects were stimulated with predicted 9-11mer CD8 + T cell epitopes from P. falciparum circumsporozoite protein (CSP), apical membrane antigen 1 (AMA1), thrombospondin related anonymous protein (TRAP) and cell traversal for ookinetes and sporozoites (CelTOS) in FluoroSpot assays. A total of 135 epitopes out of 297 tested peptides from the four antigens were experimentally identified as positive for IFN-γ and/or granzyme B production in 65 of the 109 subjects. Forty-three of 135 epitopes (32 %) were promiscuous for HLA binding, with 31 of these promiscuous epitopes (72 %) being presented by HLA alleles that fall within at least two different HLA supertypes. Furthermore, about 52 % of identified epitopes were conserved when the respective sequences were aligned with those from 16 highly diverse P. falciparum parasite strains. In summary, we have identified a number of conserved epitopes, immune responses to which could be effective against multiple P. falciparum parasite strains in genetically diverse populations.
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Affiliation(s)
- Maria Belmonte
- Malaria Department, Naval Medical Research Center, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Harini Ganeshan
- Malaria Department, Naval Medical Research Center, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Jun Huang
- Malaria Department, Naval Medical Research Center, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Arnel Belmonte
- Malaria Department, Naval Medical Research Center, MD, USA; GDIT, MD 20817, USA
| | - Sandra Inoue
- Malaria Department, Naval Medical Research Center, MD, USA; GDIT, MD 20817, USA
| | - Rachel Velasco
- Malaria Department, Naval Medical Research Center, MD, USA; GDIT, MD 20817, USA
| | - Neda Acheampong
- Malaria Department, Naval Medical Research Center, MD, USA; GDIT, MD 20817, USA
| | - Ebenezer Addo Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Kwadwo Akyea-Mensah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Augustina Frimpong
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Nana Aba Ennuson
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Abena Fremaah Frempong
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Eric Kyei-Baafour
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Linda Eva Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Kimberly Edgel
- Malaria Department, Naval Medical Research Center, MD, USA
| | - Bjoern Peters
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | | | - Kwadwo Asamoah Kusi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.
| | - Martha Sedegah
- Malaria Department, Naval Medical Research Center, MD, USA
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Richie TL, Church LWP, Murshedkar T, Billingsley PF, James ER, Chen MC, Abebe Y, KC N, Chakravarty S, Dolberg D, Healy SA, Diawara H, Sissoko MS, Sagara I, Cook DM, Epstein JE, Mordmüller B, Kapulu M, Kreidenweiss A, Franke-Fayard B, Agnandji ST, López Mikue MSA, McCall MBB, Steinhardt L, Oneko M, Olotu A, Vaughan AM, Kublin JG, Murphy SC, Jongo S, Tanner M, Sirima SB, Laurens MB, Daubenberger C, Silva JC, Lyke KE, Janse CJ, Roestenberg M, Sauerwein RW, Abdulla S, Dicko A, Kappe SHI, Lee Sim BK, Duffy PE, Kremsner PG, Hoffman SL. Sporozoite immunization: innovative translational science to support the fight against malaria. Expert Rev Vaccines 2023; 22:964-1007. [PMID: 37571809 PMCID: PMC10949369 DOI: 10.1080/14760584.2023.2245890] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 08/04/2023] [Indexed: 08/13/2023]
Abstract
INTRODUCTION Malaria, a devastating febrile illness caused by protozoan parasites, sickened 247,000,000 people in 2021 and killed 619,000, mostly children and pregnant women in sub-Saharan Africa. A highly effective vaccine is urgently needed, especially for Plasmodium falciparum (Pf), the deadliest human malaria parasite. AREAS COVERED Sporozoites (SPZ), the parasite stage transmitted by Anopheles mosquitoes to humans, are the only vaccine immunogen achieving >90% efficacy against Pf infection. This review describes >30 clinical trials of PfSPZ vaccines in the U.S.A., Europe, Africa, and Asia, based on first-hand knowledge of the trials and PubMed searches of 'sporozoites,' 'malaria,' and 'vaccines.' EXPERT OPINION First generation (radiation-attenuated) PfSPZ vaccines are safe, well tolerated, 80-100% efficacious against homologous controlled human malaria infection (CHMI) and provide 18-19 months protection without boosting in Africa. Second generation chemo-attenuated PfSPZ are more potent, 100% efficacious against stringent heterologous (variant strain) CHMI, but require a co-administered drug, raising safety concerns. Third generation, late liver stage-arresting, replication competent (LARC), genetically-attenuated PfSPZ are expected to be both safe and highly efficacious. Overall, PfSPZ vaccines meet safety, tolerability, and efficacy requirements for protecting pregnant women and travelers exposed to Pf in Africa, with licensure for these populations possible within 5 years. Protecting children and mass vaccination programs to block transmission and eliminate malaria are long-term objectives.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Sara A. Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Halimatou Diawara
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Mahamadou S. Sissoko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Issaka Sagara
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - David M. Cook
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Judith E. Epstein
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Benjamin Mordmüller
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Melissa Kapulu
- Biosciences Department, Kenya Medical Research Institute KEMRI-Wellcome Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Andrea Kreidenweiss
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | | | - Selidji T. Agnandji
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | | | - Matthew B. B. McCall
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Laura Steinhardt
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Martina Oneko
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
| | - Ally Olotu
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Ashley M. Vaughan
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - James G. Kublin
- Department of Global Health, University of Washington, Seattle, WA, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Sean C. Murphy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Center for Emerging and Re-emerging Infectious Diseases and Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Said Jongo
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Marcel Tanner
- Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Matthew B. Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Claudia Daubenberger
- Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Joana C. Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kirsten E. Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Chris J. Janse
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - Robert W. Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Salim Abdulla
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Alassane Dicko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Stefan H. I. Kappe
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | | | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Peter G. Kremsner
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
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Design of a Chimeric Multi-Epitope Vaccine (CMEV) against Both Leishmania martiniquensis and Leishmania orientalis Parasites Using Immunoinformatic Approaches. BIOLOGY 2022; 11:biology11101460. [PMID: 36290364 PMCID: PMC9598663 DOI: 10.3390/biology11101460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/21/2022] [Accepted: 09/30/2022] [Indexed: 01/24/2023]
Abstract
Leishmaniasis is a parasitic disease caused by protozoan flagellates of the genus Leishmania. Recently, Leishmania martiniquensis and Leishmania orientalis, emerging species of Leishmania, were isolated from patients in Thailand. Development of the vaccine is demanded; however, genetic differences between the two species make it difficult to design a vaccine that is effective for both species. In this study, we applied immuno-informatic approaches to design a chimeric multi-epitope vaccine (CMEV) against both L. martiniquensis and L. orientalis. We identified seven helper T lymphocyte (HTL) epitopes, sixteen cytotoxic T lymphocyte (CTL) epitopes, and eleven B-cell epitopes from sixteen conserved antigenic proteins found in both species. All these epitopes were joined together, and to further enhance immunogenicity, protein and peptides adjuvant were also added at the N-terminal of the molecule by using specific linkers. The candidate CMEV was subsequently analyzed from the perspectives of the antigenicity, allergenicity, and physiochemical properties. The interaction of the designed multi-epitope vaccine and immune receptor (TLR4) of the host were evaluated based on molecular dockings of the predicted 3D structures. Finally, in silico cloning was performed to construct the expression vaccine vector. Docking analysis showed that the vaccine/TLR4 complex took a stable form. Based on the predicted immunogenicity, physicochemical, and structural properties in silico, the vaccine candidate was expected to be appropriately expressed in bacterial expression systems and show the potential to induce a host immune response. This study proposes the experimental validation of the efficacy of the candidate vaccine construct against the two Leishmania.
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Kusi KA, Ofori EA, Akyea-Mensah K, Kyei-Baafour E, Frimpong A, Ennuson NA, Belmonte M, Ganeshan H, Huang J, Amoah LE, Villasante E, Sedegah M. Towards large-scale identification of HLA-restricted T cell epitopes from four vaccine candidate antigens in a malaria endemic community in Ghana. Vaccine 2021; 40:757-764. [PMID: 34969544 DOI: 10.1016/j.vaccine.2021.12.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 12/06/2021] [Accepted: 12/16/2021] [Indexed: 11/24/2022]
Abstract
Sterile protection against clinical malaria has been achieved in animal models and experimental human challenge studies involving immunization with radiation attenuated Plasmodium falciparum sporozoite vaccines as well as by live sporozoites under chloroquine prophylaxis. Parasite-specific IFN-γ and granzyme B-secreting CD8 + T cells have been identified as key mediators of protection. Although the exact parasite targets of protective CD8 + T cell responses are not fully defined, responses against a handful of vaccine candidate antigens have been associated with protection. Identifying the T cell targets in these antigens will facilitate the development of simpler, cost-effective, and efficacious next generation multi-epitope vaccines. The aim of this study was to identify immunodominant portions of four malaria vaccine candidate antigens using peripheral blood mononuclear cells (PBMCs) from adults with life-long exposure to malaria parasites. Cryopreserved PBMCs from 291 HLA-typed subjects were stimulated with pools of overlapping 15mer peptides spanning the entire sequences of P. falciparum circumsporozoite protein (CSP, 9 pools), apical membrane antigen 1 (AMA1, 12 pools), thrombospondin related anonymous protein (TRAP, 6 pools) and cell traversal for ookinetes and sporozoites (CelTOS, 4 pools) in FluoroSpot assays. 125 of 291 subjects made IFN-γ responses to 30 of the 31 peptide pools tested and 22 of 291 made granzyme B responses, with 20 making dual responses. The most frequent responses were to the CSP C-terminal region and the least frequent responses were to TRAP and CelTOS. There was no association between FluoroSpot responses and active malaria infection, detected by either microscopy, RDT, or PCR. In conclusion, CSP and AMA1 have relatively higher numbers of epitopes that trigger IFN-γ and granzyme B-secreting T cells in adults with life-long malaria parasite exposure compared to the other two antigens tested, and highlights the continued relevance of these two antigens as vaccine candidates.
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Affiliation(s)
- Kwadwo Asamoah Kusi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.
| | - Ebenezer Addo Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Kwadwo Akyea-Mensah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Eric Kyei-Baafour
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Augustina Frimpong
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Nana Aba Ennuson
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Maria Belmonte
- Malaria Department, Naval Medical Research Center, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Harini Ganeshan
- Malaria Department, Naval Medical Research Center, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Jun Huang
- Malaria Department, Naval Medical Research Center, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Linda Eva Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | | | - Martha Sedegah
- Malaria Department, Naval Medical Research Center, MD, USA
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Joyce S, Ternette N. Know thy immune self and non-self: Proteomics informs on the expanse of self and non-self, and how and where they arise. Proteomics 2021; 21:e2000143. [PMID: 34310018 PMCID: PMC8865197 DOI: 10.1002/pmic.202000143] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/30/2021] [Accepted: 07/19/2021] [Indexed: 12/30/2022]
Abstract
T cells play an important role in the adaptive immune response to a variety of infections and cancers. Initiation of a T cell mediated immune response requires antigen recognition in a process termed MHC (major histocompatibility complex) restri ction. A T cell antigen is a composite structure made up of a peptide fragment bound within the antigen‐binding groove of an MHC‐encoded class I or class II molecule. Insight into the precise composition and biology of self and non‐self immunopeptidomes is essential to harness T cell mediated immunity to prevent, treat, or cure infectious diseases and cancers. T cell antigen discovery is an arduous task! The pioneering work in the early 1990s has made large‐scale T cell antigen discovery possible. Thus, advancements in mass spectrometry coupled with proteomics and genomics technologies make possible T cell antigen discovery with ease, accuracy, and sensitivity. Yet we have only begun to understand the breadth and the depth of self and non‐self immunopeptidomes because the molecular biology of the cell continues to surprise us with new secrets directly related to the source, and the processing and presentation of MHC ligands. Focused on MHC class I molecules, this review, therefore, provides a brief historic account of T cell antigen discovery and, against a backdrop of key advances in molecular cell biologic processes, elaborates on how proteogenomics approaches have revolutionised the field.
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Affiliation(s)
- Sebastian Joyce
- Department of Veterans Affairs, Tennessee Valley Healthcare System and the Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Nicola Ternette
- Centre for Cellular and Molecular Physiology, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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7
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Noe AR, Terry FE, Schanen BC, Sassano E, Hindocha P, Phares TW, Moise L, Christen JM, Tucker KD, Kotraiah V, Drake DR, Martin WD, De Groot AS, Gutierrez GM. Bridging Computational Vaccinology and Vaccine Development Through Systematic Identification, Characterization, and Downselection of Conserved and Variable Circumsporozoite Protein CD4 T Cell Epitopes From Diverse Plasmodium falciparum Strains. Front Immunol 2021; 12:689920. [PMID: 34168657 PMCID: PMC8217813 DOI: 10.3389/fimmu.2021.689920] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/06/2021] [Indexed: 11/13/2022] Open
Abstract
An effective malaria vaccine must prevent disease in a range of populations living in regions with vastly different transmission rates and protect against genetically-diverse Plasmodium falciparum (Pf) strains. The protective efficacy afforded by the currently licensed malaria vaccine, Mosquirix™, promotes strong humoral responses to Pf circumsporozoite protein (CSP) 3D7 but protection is limited in duration and by strain variation. Helper CD4 T cells are central to development of protective immune responses, playing roles in B cell activation and maturation processes, cytokine production, and stimulation of effector T cells. Therefore, we took advantage of recent in silico modeling advances to predict and analyze human leukocyte antigen (HLA)-restricted class II epitopes from PfCSP – across the entire PfCSP 3D7 sequence as well as in 539 PfCSP sequence variants – with the goal of improving PfCSP-based malaria vaccines. Specifically, we developed a systematic workflow to identify peptide sequences capable of binding HLA-DR in a context relevant to achieving broad human population coverage utilizing cognate T cell help and with limited T regulatory cell activation triggers. Through this workflow, we identified seven predicted class II epitope clusters in the N- and C-terminal regions of PfCSP 3D7 and an additional eight clusters through comparative analysis of 539 PfCSP sequence variants. A subset of these predicted class II epitope clusters was synthesized as peptides and assessed for HLA-DR binding in vitro. Further, we characterized the functional capacity of these peptides to prime and activate human peripheral blood mononuclear cells (PBMCs), by monitoring cytokine response profiles using MIMIC® technology (Modular IMmune In vitro Construct). Utilizing this decision framework, we found sufficient differential cellular activation and cytokine profiles among HLA-DR-matched PBMC donors to downselect class II epitope clusters for inclusion in a vaccine targeting PfCSP. Importantly, the downselected clusters are not highly conserved across PfCSP variants but rather, they overlap a hypervariable region (TH2R) in the C-terminus of the protein. We recommend assessing these class II epitope clusters within the context of a PfCSP vaccine, employing a test system capable of measuring immunogenicity across a broad set of HLA-DR alleles.
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Affiliation(s)
- Amy R Noe
- Leidos Life Sciences, Leidos Inc., Frederick, MD, United States
| | | | - Brian C Schanen
- Sanofi Pasteur, VaxDesign Campus, Orlando, FL, United States
| | - Emily Sassano
- Sanofi Pasteur, VaxDesign Campus, Orlando, FL, United States
| | | | | | | | | | | | | | - Donald R Drake
- Sanofi Pasteur, VaxDesign Campus, Orlando, FL, United States
| | | | - Anne S De Groot
- EpiVax Inc., Providence, RI, United States.,University of Georgia Center for Vaccines and Immunology, Athens, GA, United States
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8
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Tucker KD, Schanen BC, Phares TW, Sassano E, Terry FE, Hindocha P, Moise L, Kotraiah V, Martin WD, De Groot AS, Drake DR, Gutierrez GM, Noe AR. Identification, Selection and Immune Assessment of Liver Stage CD8 T Cell Epitopes From Plasmodium falciparum. Front Immunol 2021; 12:684116. [PMID: 34025684 PMCID: PMC8138313 DOI: 10.3389/fimmu.2021.684116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 04/13/2021] [Indexed: 11/13/2022] Open
Abstract
Immunization with radiation-attenuated sporozoites (RAS) has been shown to protect against malaria infection, primarily through CD8 T cell responses, but protection is limited based on parasite strain. Therefore, while CD8 T cells are an ideal effector population target for liver stage malaria vaccine development strategies, such strategies must incorporate conserved epitopes that cover a large range of class I human leukocyte antigen (HLA) supertypes to elicit cross-strain immunity across the target population. This approach requires identifying and characterizing a wide range of CD8 T cell epitopes for incorporation into a vaccine such that coverage across a large range of class I HLA alleles is attained. Accordingly, we devised an experimental framework to identify CD8 T cell epitopes from novel and minimally characterized antigens found at the pre-erythrocytic stage of parasite development. Through in silico analysis we selected conserved P. falciparum proteins, using P. vivax orthologues to establish stringent conservation parameters, predicted to have a high number of T cell epitopes across a set of six class I HLA alleles representative of major supertypes. Using the decision framework, five proteins were selected based on the density and number of predicted epitopes. Selected epitopes were synthesized as peptides and evaluated for binding to the class I HLA alleles in vitro to verify in silico binding predictions, and subsequently for stimulation of human T cells using the Modular IMmune In-vitro Construct (MIMIC®) technology to verify immunogenicity. By combining the in silico tools with the ex vivo high throughput MIMIC platform, we identified 15 novel CD8 T cell epitopes capable of stimulating an immune response in alleles across the class I HLA panel. We recommend these epitopes should be evaluated in appropriate in vivo humanized immune system models to determine their protective efficacy for potential inclusion in future vaccines.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Anne S. De Groot
- EpiVax Inc., Providence, RI, United States
- University of Georgia Center for Vaccines and Immunology, Athens, GA, United States
| | | | | | - Amy R. Noe
- Leidos Life Sciences, Leidos Inc., Frederick, MD, United States
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9
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Adiga R. Benchmarking Datasets from Malaria Cytotoxic T-cell Epitopes Using Machine Learning Approach. Avicenna J Med Biotechnol 2021; 13:87-91. [PMID: 34012524 PMCID: PMC8112139 DOI: 10.18502/ajmb.v13i2.5527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Background: Epitope prediction remains a major challenge in malaria due to the unique parasite biology, in addition to rapidly evolving parasite sequence variation in Plasmodium species. Although several models for epitope prediction exist, they are not useful in Plasmodium specific epitope development. Hence, it was proposed to use machine learning based methods to develop a peptide sequence based epitope predictor specific for malaria. Methods: Model datasets were developed and performance was tested using various machine learning algorithms. Machine learning classifiers were trained on epitope data using sequence features and comparison of amino acid physicochemical properties was done to yield a valid prediction model. Results: The findings from the analysis reveal that the model developed using selected classifiers after preprocessing by Waikato Environment for Knowledge Analysis (WEKA) performed better than other methods. The datasets for benchmarks of performance are deposited in the repository https://github.com/githubramaadiga/epitope_dataset
. Conclusion: The study is the first in-silico study on benchmarking Plasmodium cytotoxic T cell epitope datasets using machine learning approach. The peptide based predictors have been used for the first time to classify cytotoxic T cell epitopes in malaria. Algorithms has been evaluated using real datasets from malaria to obtain the model.
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Affiliation(s)
- Rama Adiga
- Nitte (Deemed to be University), Nitte University Centre for Science Education & Research (NUCSER), Division of Bioinformatics and Computational Genomics, Deralakatte, Paneer Campus, Mangalore, India 575018
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10
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Almeida MEMD, Vasconcelos MGSD, Tarragô AM, Mariúba LAM. Circumsporozoite Surface Protein-based malaria vaccines: a review. Rev Inst Med Trop Sao Paulo 2021; 63:e11. [PMID: 33533814 PMCID: PMC7845937 DOI: 10.1590/s1678-9946202163011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/20/2020] [Indexed: 12/03/2022] Open
Abstract
Malaria represents a serious public health problem, presenting with high rates of incidence, morbidity and mortality in tropical and subtropical regions of the world. According to the World Health Organization, in 2018 there were 228 million cases and 405 thousand deaths caused by this disease in the world, affecting mainly children and pregnant women in Africa. Despite the programs carried out to control this disease, drug resistance and invertebrate vector resistance to insecticides have generated difficulties. An efficient vaccine against malaria would be a strategy with a high impact on the eradication and control of this disease. Researches aimed at developing vaccines have focused on antigens of high importance for the survival of the parasite such as the Circumsporozoite Surface Protein, involved in the pre-erythrocytic cycle during parasites invasion in hepatocytes. Currently, RTS’S is the most promising vaccine for malaria and was constructed using CSP; its performance was evaluated using two types of adjuvants: AS01 and AS02. The purpose of this review was to provide a bibliographic survey of historical researches that led to the development of RTS’S and its performance analysis over the decade. The search for new adjuvants to be associated with this antigen seems to be a way to obtain higher percentages of protection for a future malaria vaccine.
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Affiliation(s)
- Maria Edilene Martins de Almeida
- Fiocruz Amazônia, Instituto Leônidas e Maria Deane, Laboratório de Diagnóstico e Controle de Doenças Infecciosas na Amazônia, Amazonas, Manaus, Brazil.,Fiocruz, Instituto Oswaldo Cruz, Programa de Pós-Graduação Stricto Sensu em Biologia Celular e Molecular, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maria Gabriella Santos de Vasconcelos
- Fiocruz Amazônia, Instituto Leônidas e Maria Deane, Laboratório de Diagnóstico e Controle de Doenças Infecciosas na Amazônia, Amazonas, Manaus, Brazil.,Centro Universitário Fametro, Manaus, Amazonas, Brazil
| | - Andréa Monteiro Tarragô
- Universidade Federal do Amazonas, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Imunologia Básica e Aplicada, Manaus, Amazonas, Brazil.,Fundação Hospitalar de Hematologia e Hemoterapia do Amazonas, Manaus, Amazonas, Brazil
| | - Luís André Morais Mariúba
- Fiocruz Amazônia, Instituto Leônidas e Maria Deane, Laboratório de Diagnóstico e Controle de Doenças Infecciosas na Amazônia, Amazonas, Manaus, Brazil.,Fiocruz, Instituto Oswaldo Cruz, Programa de Pós-Graduação Stricto Sensu em Biologia Celular e Molecular, Rio de Janeiro, Rio de Janeiro, Brazil.,Universidade Federal do Amazonas, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Imunologia Básica e Aplicada, Manaus, Amazonas, Brazil.,Universidade Federal do Amazonas, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biotecnologia, Manaus, Amazonas, Brazil
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11
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Cai C, Hu Z, Yu X. Accelerator or Brake: Immune Regulators in Malaria. Front Cell Infect Microbiol 2020; 10:610121. [PMID: 33363057 PMCID: PMC7758250 DOI: 10.3389/fcimb.2020.610121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022] Open
Abstract
Malaria is a life-threatening infectious disease, affecting over 250 million individuals worldwide each year, eradicating malaria has been one of the greatest challenges to public health for a century. Growing resistance to anti-parasitic therapies and lack of effective vaccines are major contributing factors in controlling this disease. However, the incomplete understanding of parasite interactions with host anti-malaria immunity hinders vaccine development efforts to date. Recent studies have been unveiling the complexity of immune responses and regulators against Plasmodium infection. Here, we summarize our current understanding of host immune responses against Plasmodium-derived components infection and mainly focus on the various regulatory mechanisms mediated by recent identified immune regulators orchestrating anti-malaria immunity.
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Affiliation(s)
- Chunmei Cai
- Research Center for High Altitude Medicine, School of Medical, Qinghai University, Xining, China
- Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province, Qinghai University, Xining, China
| | - Zhiqiang Hu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiao Yu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Lab of Single Cell Technology and Application, Southern Medical University, Guangzhou, China
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12
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Schmaler M, Orlova-Fink N, Rutishauser T, Abdulla S, Daubenberger C. Human unconventional T cells in Plasmodium falciparum infection. Semin Immunopathol 2020; 42:265-277. [PMID: 32076813 PMCID: PMC7223888 DOI: 10.1007/s00281-020-00791-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 02/07/2020] [Indexed: 12/22/2022]
Abstract
Malaria is an old scourge of humankind and has a large negative impact on the economic development of affected communities. Recent success in malaria control and reduction of mortality seems to have stalled emphasizing that our current intervention tools need to be complemented by malaria vaccines. Different populations of unconventional T cells such as mucosal-associated invariant T (MAIT) cells, invariant natural killer T (iNKT) cells and γδ T cells are gaining attention in the field of malaria immunology. Significant advances in our basic understanding of unconventional T cell biology in rodent malaria models have been made, however, their roles in humans during malaria are less clear. Unconventional T cells are abundant in skin, gut and liver tissues, and long-lasting expansions and functional alterations were observed upon malaria infection in malaria naïve and malaria pre-exposed volunteers. Here, we review the current understanding of involvement of unconventional T cells in anti-Plasmodium falciparum immunity and highlight potential future research avenues.
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Affiliation(s)
- Mathias Schmaler
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Nina Orlova-Fink
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Tobias Rutishauser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Salim Abdulla
- Ifakara Health Institute, Bagamoyo Clinical Trial Unit, Bagamoyo, Tanzania
| | - Claudia Daubenberger
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.
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13
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Abstract
Immunity to malaria has been linked to the availability and function of helper CD4+ T cells, cytotoxic CD8+ T cells and γδ T cells that can respond to both the asymptomatic liver stage and the symptomatic blood stage of Plasmodium sp. infection. These T cell responses are also thought to be modulated by regulatory T cells. However, the precise mechanisms governing the development and function of Plasmodium-specific T cells and their capacity to form tissue-resident and long-lived memory populations are less well understood. The field has arrived at a point where the push for vaccines that exploit T cell-mediated immunity to malaria has made it imperative to define and reconcile the mechanisms that regulate the development and functions of Plasmodium-specific T cells. Here, we review our current understanding of the mechanisms by which T cell subsets orchestrate host resistance to Plasmodium infection on the basis of observational and mechanistic studies in humans, non-human primates and rodent models. We also examine the potential of new experimental strategies and human infection systems to inform a new generation of approaches to harness T cell responses against malaria.
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14
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Bettencourt P. Current Challenges in the Identification of Pre-Erythrocytic Malaria Vaccine Candidate Antigens. Front Immunol 2020; 11:190. [PMID: 32153565 PMCID: PMC7046804 DOI: 10.3389/fimmu.2020.00190] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/24/2020] [Indexed: 12/27/2022] Open
Abstract
Plasmodium spp.-infected mosquitos inject sporozoites into the skin of a mammalian host during a blood meal. These enter the host's circulatory system and establish an infection in the liver. After a silent metamorphosis, merozoites invade the blood leading to the symptomatic and transmissible stages of malaria. The silent pre-erythrocytic malaria stage represents a bottleneck in the disease which is ideal to block progression to clinical malaria, through chemotherapeutic and immunoprophylactic interventions. RTS,S/AS01, the only malaria vaccine close to licensure, although with poor efficacy, blocks the sporozoite invasion mainly through the action of antibodies against the CSP protein, a major component of the pellicle of the sporozoite. Strikingly, sterile protection against malaria can be obtained through immunization with radiation-attenuated sporozoites, genetically attenuated sporozoites or through chemoprophylaxis with infectious sporozoites in animals and humans, but the deployability of sporozoite-based live vaccines pose tremendous challenges. The protection induced by sporozoites occurs in the pre-erythrocytic stages and is mediated mainly by antibodies against the sporozoite and CD8+ T cells against peptides presented by MHC class I molecules in infected hepatocytes. Thus, the identification of malaria antigens expressed in the sporozoite and liver-stage may provide new vaccine candidates to be included, alone or in combination, as recombinant protein-based, virus-like particles or sub-unit virally-vectored vaccines. Here I review the efforts being made to identify Plasmodium falciparum antigens expressed during liver-stage with focus on the development of parasite, hepatocyte, mouse models, and resulting rate of infection in order to identify new vaccine candidates and to improve the efficacy of the current vaccines. Finally, I propose new approaches for the identification of liver-stage antigens based on immunopeptidomics.
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15
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Kusi KA, Aggor FE, Amoah LE, Anum D, Nartey Y, Amoako-Sakyi D, Obiri-Yeboah D, Hollingdale M, Ganeshan H, Belmonte M, Peters B, Kim Y, Tetteh J, Kyei-Baafour E, Dodoo D, Villasante E, Sedegah M. Identification of Plasmodium falciparum circumsporozoite protein-specific CD8+ T cell epitopes in a malaria exposed population. PLoS One 2020; 15:e0228177. [PMID: 32040522 PMCID: PMC7010280 DOI: 10.1371/journal.pone.0228177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/08/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Sterile protection against malaria, most likely mediated by parasite-specific CD8+ T cells, has been achieved by attenuated sporozoite vaccination of animals as well as malaria-naïve and malaria-exposed subjects. The circumsporozoite protein (CSP)-based vaccine, RTS,S, shows low efficacy partly due to limited CD8+ T cell induction, and inclusion of such epitopes could improve RTS,S. This study assessed 8-10mer CSP peptide epitopes, present in predicted or previously positive P. falciparum 3D7 CSP 15mer overlapping peptide pools, for their ability to induce CD8+ T cell IFN-γ responses in natural malaria-exposed subjects. METHODS Cryopreserved PBMCs from nine HLA-typed subjects were stimulated with 23 8-10mer CSP peptides from the 3D7 parasite in IFN-ɣ ELISpot assays. The CD8+ T cell specificity of IFN-γ responses was confirmed in ELISpot assays using CD8+ T cell-enriched PBMC fractions after CD4+ cell depletion. RESULTS Ten of 23 peptide epitopes elicited responses in whole PBMCs from five of the nine subjects. Four peptides tested positive in CD8+ T cell-enriched PBMCs from two previously positive responders and one new subject. All four immunodominant peptides are restricted by globally common HLA supertypes (A02, A03, B07) and mapped to regions of the CSP antigen with limited or no reported polymorphism. Association of these peptide-specific responses with anti-malarial protection remains to be confirmed. CONCLUSIONS The relatively conserved nature of the four identified epitopes and their binding to globally common HLA supertypes makes them good candidates for inclusion in potential multi-epitope malaria vaccines.
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Affiliation(s)
- Kwadwo A. Kusi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
- * E-mail:
| | - Felix E. Aggor
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Linda E. Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra, Ghana
- Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Dorothy Anum
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra, Ghana
| | - Yvonne Nartey
- Department of Microbiology and Immunology, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Daniel Amoako-Sakyi
- Department of Microbiology and Immunology, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Dorcas Obiri-Yeboah
- Department of Microbiology and Immunology, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Michael Hollingdale
- Malaria Department, Naval Medical Research Center, Silver Springs, MD, United States of America
| | - Harini Ganeshan
- Malaria Department, Naval Medical Research Center, Silver Springs, MD, United States of America
| | - Maria Belmonte
- Malaria Department, Naval Medical Research Center, Silver Springs, MD, United States of America
| | - Bjoern Peters
- La Jolla Institute for Immunology, La Jolla, CA, United States of America
| | - Yohan Kim
- La Jolla Institute for Immunology, La Jolla, CA, United States of America
| | - John Tetteh
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra, Ghana
| | - Eric Kyei-Baafour
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra, Ghana
| | - Daniel Dodoo
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra, Ghana
| | - Eileen Villasante
- Malaria Department, Naval Medical Research Center, Silver Springs, MD, United States of America
| | - Martha Sedegah
- Malaria Department, Naval Medical Research Center, Silver Springs, MD, United States of America
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16
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Heide J, Wildner NH, Ackermann C, Wittner M, Marget M, Sette A, Sidney J, Jacobs T, Schulze Zur Wiesch J. Detection of EXP1-Specific CD4+ T Cell Responses Directed Against a Broad Range of Epitopes Including Two Promiscuous MHC Class II Binders During Acute Plasmodium falciparum Malaria. Front Immunol 2020; 10:3037. [PMID: 32038611 PMCID: PMC6993587 DOI: 10.3389/fimmu.2019.03037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 12/11/2019] [Indexed: 01/02/2023] Open
Abstract
Background: T cells are thought to play a major role in conferring immunity against malaria. This study aimed to comprehensively define the breadth and specificity of the Plasmodium falciparum (P. falciparum)-specific CD4+ T cell response directed against the exported protein 1 (EXP1) in a cohort of patients diagnosed with acute malaria. Methods: Peripheral blood mononuclear cells of 44 patients acutely infected with P. falciparum, and of one patient infected with P. vivax, were stimulated and cultured in vitro with an overlapping set of 31 P. falciparum-specific 13-17-mer peptides covering the entire EXP1 sequence. EXP1-specific T cell responses were analyzed by ELISPOT and intracellular cytokine staining for interferon-γ production after re-stimulation with individual peptides. For further characterization of the epitopes, in silico and in vitro human leukocyte antigen (HLA) binding studies and fine mapping assays were performed. Results: We detected one or more EXP1-specific CD4+ T cell responses (mean: 1.09, range 0–5) in 47% (21/45) of our patients. Responses were directed against 15 of the 31 EXP1 peptides. Peptides EXP1-P13 (aa60-74) and P15 (aa70-85) were detected by 18% (n = 8) and 27% (n = 12) of the 45 patients screened. The optimal length, as well as the corresponding most likely HLA-restriction, of each of these two peptides was assessed. Interestingly, we also identified one CD4+ T cell response against peptide EXP1-P15 in a patient who was infected with P. vivax but not falciparum. Conclusions: This first detailed characterization of novel EXP1-specific T cell epitopes provides important information for future analysis with major histocompatibility complex-multimer technology as well as for immunomonitoring and vaccine design.
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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
| | - Nils H Wildner
- Infectious Diseases Unit, I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christin Ackermann
- Infectious Diseases Unit, I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Melanie Wittner
- 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
| | - Matthias Marget
- Department of Transfusion Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alessandro Sette
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States.,Division of Infectious Diseases, Department of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - John Sidney
- Division of Vaccine Discovery, La Jolla Institute for Immunology, La Jolla, CA, United States
| | - Thomas Jacobs
- Protozoa Immunology, Bernhard-Nocht-Institute for 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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17
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Mehrizi AA, Jafari Zadeh A, Zakeri S, Djadid ND. Population genetic structure analysis of thrombospondin-related adhesive protein (TRAP) as a vaccine candidate antigen in worldwide Plasmodium falciparum isolates. INFECTION GENETICS AND EVOLUTION 2020; 80:104197. [PMID: 31954917 DOI: 10.1016/j.meegid.2020.104197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 01/12/2020] [Accepted: 01/15/2020] [Indexed: 02/07/2023]
Abstract
Antigenic diversity is a major concern in malaria vaccine development that requires to be considered in developing a malaria vaccine. Plasmodium falciparum thrombospondin-related adhesive protein (PfTRAP) is a leading malaria vaccine candidate antigen. In the current study, we investigated the level of genetic diversity and natural selection of pftrap sequences in P. falciparum isolates from Iran (n = 47). The gene diversity of Iranian pftrap sequences was also compared to available global pftrap sequences deposited in the GenBank or PlasmoDB databases (n = 220). Comparison of Iranian PfTRAP sequences with T9/96 reference sequence showed the presence of 35 amino acid changes in 32 positions and a limited variation in repeat sequences, leading to 13 distinct haplotypes. The overall nucleotide diversity (π) for the ectodomain of Iranian pftrap sequences was 0.00444 ± 0.00043, with the highest diversity in Domain IV. Alignment comparison of global PfTRAP sequences with T9/96 reference sequence indicated 96 amino acid replacements as well as extensive variable repeat sequences (9-23 repeats), which led to 192 haplotypes. Among the global isolates, the lowest nucleotide diversity was detected in French Guianan (0.00428 ± 0.00163) and Iranian (0.00444 ± 0.00043) pftrap sequences, and the most variation was observed in domains II and IV in all populations. The dN-dS value displayed the evidence of positive selection due to recombination and immune system pressure. The Fst analysis revealed a gene flow between African populations; however, genetic differentiation observed between Iranian and other populations probably was due to gene flow barriers. Both conserved and variable epitopes were predicted in B- and T-cell epitopes of PfTRAP antigen. The obtained results from this study could be helpful for developing a PfTRAP-based malaria vaccine.
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Affiliation(s)
- Akram Abouie Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O.BOX 1316943551, Tehran, Iran.
| | - Azadeh Jafari Zadeh
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O.BOX 1316943551, Tehran, Iran
| | - Sedigheh Zakeri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O.BOX 1316943551, Tehran, Iran
| | - Navid Dinparast Djadid
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O.BOX 1316943551, Tehran, Iran
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18
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Reeder SM, Reuschel EL, Bah MA, Yun K, Tursi NJ, Kim KY, Chu J, Zaidi FI, Yilmaz I, Hart RJ, Perrin B, Xu Z, Humeau L, Weiner DB, Aly ASI. Synthetic DNA Vaccines Adjuvanted with pIL-33 Drive Liver-Localized T Cells and Provide Protection from Plasmodium Challenge in a Mouse Model. Vaccines (Basel) 2020; 8:vaccines8010021. [PMID: 31936739 PMCID: PMC7157753 DOI: 10.3390/vaccines8010021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/03/2020] [Accepted: 01/06/2020] [Indexed: 12/11/2022] Open
Abstract
The need for a malaria vaccine is indisputable. A single vaccine for Plasmodium pre-erythrocytic stages targeting the major sporozoite antigen circumsporozoite protein (CSP) has had partial success. Additionally, CD8+ T cells targeting liver-stage (LS) antigens induced by live attenuated sporozoite vaccines were associated with protection in human challenge experiments. To further evaluate protection mediated by LS antigens, we focused on exported pre-erythrocytic proteins (exported protein 1 (EXP1), profilin (PFN), exported protein 2 (EXP2), inhibitor of cysteine proteases (ICP), transmembrane protein 21 (TMP21), and upregulated in infective sporozoites-3 (UIS3)) expressed in all Plasmodium species and designed optimized, synthetic DNA (synDNA) immunogens. SynDNA antigen cocktails were tested with and without the molecular adjuvant plasmid IL-33. Immunized animals developed robust T cell responses including induction of antigen-specific liver-localized CD8+ T cells, which were enhanced by the co-delivery of plasmid IL-33. In total, 100% of mice in adjuvanted groups and 71%–88% in non-adjuvanted groups were protected from blood-stage disease following Plasmodium yoelii sporozoite challenge. This study supports the potential of synDNA LS antigens as vaccine components for malaria parasite infection.
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Affiliation(s)
- Sophia M. Reeder
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Emma L. Reuschel
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Mamadou A. Bah
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Kun Yun
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Kevin Y. Kim
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Jacqueline Chu
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Faraz I. Zaidi
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
| | - Ilknur Yilmaz
- Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul 34820, Turkey
| | - Robert J. Hart
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Benjamin Perrin
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Ziyang Xu
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Laurent Humeau
- Inovio Pharmaceuticals, Inc., Plymouth Meeting, PA 19462, USA
| | - David B. Weiner
- The Vaccine Center, Wistar Institute, Philadelphia, PA 19104, USA
- Correspondence: (D.B.W.); (A.S.I.A.)
| | - Ahmed S. I. Aly
- Beykoz Institute of Life Sciences and Biotechnology, Bezmialem Vakif University, Istanbul 34820, Turkey
- Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA
- Correspondence: (D.B.W.); (A.S.I.A.)
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Zenklusen I, Jongo S, Abdulla S, Ramadhani K, Lee Sim BK, Cardamone H, Flannery EL, Nguyen T, Fishbaugher M, Steel RWJ, Betz W, Carmago N, Mikolajczak S, Kappe SHI, Hoffman SL, Sack BK, Daubenberger C. Immunization of Malaria-Preexposed Volunteers With PfSPZ Vaccine Elicits Long-Lived IgM Invasion-Inhibitory and Complement-Fixing Antibodies. J Infect Dis 2019; 217:1569-1578. [PMID: 29438525 DOI: 10.1093/infdis/jiy080] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/06/2018] [Indexed: 01/17/2023] Open
Abstract
Background The assessment of antibody responses after immunization with radiation-attenuated, aseptic, purified, cryopreserved Plasmodium falciparum sporozoites (Sanaria PfSPZ Vaccine) has focused on IgG isotype antibodies. Here, we aimed to investigate if P. falciparum sporozoite binding and invasion-inhibitory IgM antibodies are induced following immunization of malaria-preexposed volunteers with PfSPZ Vaccine. Methods Using serum from volunteers immunized with PfSPZ, we measured vaccine-induced IgG and IgM antibodies to P. falciparum circumsporozoite protein (PfCSP) via ELISA. Function of this serum as well as IgM antibody fractions was measured via in vitro in an inhibition of sporozoite invasion assay. These IgM antibody fractions were also measured for binding to sporozoites by immunofluorescence assay and complement fixation on whole sporozoites. Results We found that in addition to anti-PfCSP IgG, malaria-preexposed volunteers developed anti-PfCSP IgM antibodies after immunization with PfSPZ Vaccine and that these IgM antibodies inhibited P. falciparum sporozoite invasion of hepatocytes in vitro. These IgM plasma fractions also fixed complement to whole P. falciparum sporozoites. Conclusions This is the first finding that PfCSP and P. falciparum sporozoite-binding IgM antibodies are induced following immunization of PfSPZ Vaccine in malaria-preexposed individuals and that IgM antibodies can inhibit P. falciparum sporozoite invasion into hepatocytes in vitro and fix complement on sporozoites. These findings indicate that the immunological assessment of PfSPZ Vaccine-induced antibody responses could be more sensitive if they include parasite-specific IgM in addition to IgG antibodies. Clinical Trials Registration NCT02132299.
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Affiliation(s)
- Isabelle Zenklusen
- Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
| | - Said Jongo
- Ifakara Health Institute, Clinical Trial Unit, Bagamoyo, Tanzania
| | - Salim Abdulla
- Ifakara Health Institute, Clinical Trial Unit, Bagamoyo, Tanzania
| | - Kamaka Ramadhani
- Ifakara Health Institute, Clinical Trial Unit, Bagamoyo, Tanzania
| | | | | | | | - Thao Nguyen
- Center for Infectious Disease Research, Seattle, Washington
| | | | - Ryan W J Steel
- Center for Infectious Disease Research, Seattle, Washington
| | - Will Betz
- Center for Infectious Disease Research, Seattle, Washington
| | - Nelly Carmago
- Center for Infectious Disease Research, Seattle, Washington
| | | | - Stefan H I Kappe
- Center for Infectious Disease Research, Seattle, Washington.,Department of Global Health, University of Washington, Seattle
| | | | - Brandon K Sack
- Center for Infectious Disease Research, Seattle, Washington
| | - Claudia Daubenberger
- Clinical Immunology Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Switzerland
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20
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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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21
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Kaba SA, Karch CP, Seth L, Ferlez KM, Storme CK, Pesavento DM, Laughlin PY, Bergmann-Leitner ES, Burkhard P, Lanar DE. Self-assembling protein nanoparticles with built-in flagellin domains increases protective efficacy of a Plasmodium falciparum based vaccine. Vaccine 2018; 36:906-914. [DOI: 10.1016/j.vaccine.2017.12.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/23/2017] [Accepted: 12/02/2017] [Indexed: 12/29/2022]
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22
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Karch CP, Doll TAPF, Paulillo SM, Nebie I, Lanar DE, Corradin G, Burkhard P. The use of a P. falciparum specific coiled-coil domain to construct a self-assembling protein nanoparticle vaccine to prevent malaria. J Nanobiotechnology 2017; 15:62. [PMID: 28877692 PMCID: PMC5588597 DOI: 10.1186/s12951-017-0295-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 08/29/2017] [Indexed: 11/10/2022] Open
Abstract
Background The parasitic disease malaria remains a major global public health concern and no truly effective vaccine exists. One approach to the development of a malaria vaccine is to target the asexual blood stage that results in clinical symptoms. Most attempts have failed. New antigens such as P27A and P27 have emerged as potential new vaccine candidates. Multiple studies have demonstrated that antigens are more immunogenic and are better correlated with protection when presented on particulate delivery systems. One such particulate delivery system is the self-assembling protein nanoparticle (SAPN) that relies on coiled-coil domains of proteins to form stable nanoparticles. In the past we have used de novo designed amino acid domains to drive the formation of the coiled-coil scaffolds which present the antigenic epitopes on the particle surface. Results Here we use naturally occurring domains found in the tex1 protein to form the coiled-coil scaffolding of the nanoparticle. Thus, by engineering P27A and a new extended form of the coiled-coil domain P27 onto the N and C terminus of the SAPN protein monomer we have developed a particulate delivery system that effectively displays both antigens on a single particle that uses malaria tex1 sequences to form the nanoparticle scaffold. These particles are immunogenic in a murine model and induce immune responses similar to the ones observed in seropositive individuals in malaria endemic regions. Conclusions We demonstrate that our P27/P27A-SAPNs induce an immune response akin to the one in seropositive individuals in Burkina Faso. Since P27 is highly conserved among different Plasmodium species, these novel SAPNs may even provide cross-protection between Plasmodium falciparum and Plasmodium vivax the two major human malaria pathogens. As the SAPNs are also easy to manufacture and store they can be delivered to the population in need without complication thus providing a low cost malaria vaccine.
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Affiliation(s)
- Christopher P Karch
- Institute of Materials Science, University of Connecticut, Storrs, CT, 06269-3136, USA
| | - Tais A P F Doll
- Institute of Materials Science, University of Connecticut, Storrs, CT, 06269-3136, USA
| | | | - Issa Nebie
- Centre National de Recherche et de Formation sur le Paludisme, 01 BP 2208, Ouagadougou, West Africa, Burkina Faso
| | - David E Lanar
- Malaria Vaccine Branch, USMMRP-WRAIR, Walter Reed Army Institute of Research, Silver Spring, MD, 20910, USA
| | - Giampietro Corradin
- Biochemistry Department, University of Lausanne, 1066, Epalinges, Switzerland.
| | - Peter Burkhard
- Institute of Materials Science, University of Connecticut, Storrs, CT, 06269-3136, USA. .,Alpha-O Peptides AG, 4125, Riehen, Switzerland. .,Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269-3125, USA.
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23
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TCR-like antibodies mediate complement and antibody-dependent cellular cytotoxicity against Epstein-Barr virus-transformed B lymphoblastoid cells expressing different HLA-A*02 microvariants. Sci Rep 2017; 7:9923. [PMID: 28855662 PMCID: PMC5577143 DOI: 10.1038/s41598-017-10265-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 07/27/2017] [Indexed: 11/26/2022] Open
Abstract
Epstein-Barr virus (EBV) is a common gammaherpesvirus associated with various human malignancies. Antibodies with T cell receptor-like specificities (TCR-like mAbs) provide a means to target intracellular tumor- or virus-associated antigens by recognising their processed peptides presented on major histocompatibility complex (MHC) class I (pMHC) complexes. These antibodies are however thought to be relevant only for a single HLA allele. Here, we show that HLA-A*02:01-restricted EBV antigenic peptides EBNA1562-570, LMP1125-133 and LMP2A426-434 display binding degeneracy towards HLA-A*02 allelic microvariants, and that these pMHC complexes are recognised by anti-EBV TCR-like mAbs E1, L1 and L2 raised in the context of HLA-A*02:01. These antibodies bound endogenously derived pMHC targets on EBV–transformed human B lymphoblastoid cell lines expressing A*02:01, A*02:03, A*02:06 and A*02:07 alleles. More importantly, these TCR-like mAbs mediated both complement-dependent and antibody-dependent cellular cytotoxicity of these cell lines in vitro. This finding suggests the utility of TCR-like mAbs against target cells of closely related HLA subtypes, and the potential applicability of similar reagents within populations of diverse HLA-A*02 alleles.
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24
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Bruder JT, Chen P, Ekberg G, Smith EC, Lazarski CA, Myers BA, Bolton J, Sedegah M, Villasante E, Richie TL, King CR, Aguiar JC, Doolan DL, Brough DE. Profiling the Targets of Protective CD8 + T Cell Responses to Infection. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2017; 7:20-31. [PMID: 28948187 PMCID: PMC5602877 DOI: 10.1016/j.omtm.2017.08.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 08/14/2017] [Indexed: 11/22/2022]
Abstract
T cells are critical effectors of host immunity that target intracellular pathogens, such as the causative agents of HIV, tuberculosis, and malaria. The development of vaccines that induce effective cell-mediated immunity against such pathogens has proved challenging; for tuberculosis and malaria, many of the antigens targeted by protective T cells are not known. Here, we report a novel approach for screening large numbers of antigens as potential targets of T cells. Malaria provides an excellent model to test this antigen discovery platform because T cells are critical mediators of protection following immunization with live sporozoite vaccines and the specific antigen targets are unknown. We generated an adenovirus array by cloning 312 highly expressed pre-erythrocytic Plasmodium yoelii antigens into adenovirus vectors using high-throughput methodologies. The array was screened to identify antigen-specific CD8+ T cells induced by a live sporozoite vaccine regimen known to provide high levels of sterile protection mediated by CD8+ T cells. We identified 69 antigens that were targeted by CD8+ T cells induced by this vaccine regimen. The antigen that recalled the highest frequency of CD8+ T cells, PY02605, induced protective responses in mice, demonstrating proof of principle for this approach in identifying antigens for vaccine development.
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Affiliation(s)
- Joseph T. Bruder
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
- Corresponding author: Joseph T. Bruder, Summit Consulting, 567 Chestertown Street, Gaithersburg, MD 20878, USA.
| | - Ping Chen
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
| | - Greg Ekberg
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
| | - Emily C. Smith
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Suite 100, Bethesda, MD 20817, USA
| | | | - Bennett A. Myers
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
| | - Jessica Bolton
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Suite 100, Bethesda, MD 20817, USA
| | - Martha Sedegah
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Eileen Villasante
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Thomas L. Richie
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - C. Richter King
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
| | - Joao C. Aguiar
- Malaria Department, Naval Medical Research Center (NMRC), 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
- Camris International, 3 Bethesda Metro Center, 16th Floor, Bethesda, MD 20814, USA
| | - Denise L. Doolan
- Australian Institute of Tropical Health and Medicine, James Cook University, McGregor Road, Cairns, QLD 4870, Australia
| | - Douglas E. Brough
- GenVec, Inc., 910 Clopper Road, Suite 220N, Gaithersburg, MD 20878, USA
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25
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Wamae KK, Ochola-Oyier LI. Implications from predicted B-cell and T-cell epitopes of Plasmodium falciparum merozoite proteins EBA175-RII and Rh5. Bioinformation 2016; 12:82-91. [PMID: 28149040 PMCID: PMC5267949 DOI: 10.6026/97320630012082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/21/2016] [Accepted: 03/25/2016] [Indexed: 11/23/2022] Open
Abstract
The leading circumsporozoite protein (CSP) based malaria vaccine, RTS,S, though promising, has shown limited efficacy in field studies. There is therefore, still a need to identify other malaria vaccine targets. Merozoite antigens are potential vaccine candidates, since naturally acquired antibodies generated against them inhibit erythrocyte invasion and in some cases result in the clinical protection from disease. We thus used in silico tools (BCPreds, NetMHCcons and NetMHCIIpan 3.0) to predict B-cell epitopes (BCEs) and T-cell epitopes (TCEs) in two merozoite invasion proteins, EBA175-RII and Rh5. Initially, we validated these tools using CSP to determine whether the algorithms could predict the epitopes in the RTS,S vaccine. In EBA175-RII, we prioritised three BCEs 15REKRKGMKWDCKKKNDRSNY34, 420SNRKLVGKINTNSNYVHRNKQ440 and 528WISKKKEEYNKQAKQYQEYQ547, a CD8+ epitope 553KMYSEFKSI561 and a CD4+ epitope 440QNDKLFRDEWWK VIKKD456. Three Rh5 epitopes were prioritised, a BCE 344SCYNNNFCNTNGIRYHYDEY363, a CD8+ epitope 198STYGKCIAV206 and a Rh5 CD4+ epitope 180TFLDYYKHLSYNSIYHKSSTY200. All these epitopes are in the region involved in the proteins' interaction with their erythrocyte receptors, thus enabling erythrocyte invasion. Therefore, upon validation of their immunogenicity, by ELISA using serum from a malaria endemic population, antibodies to these epitopes may inhibit erythrocyte invasion. All the epitopes we predicted in EBA175-RII and Rh5 are novel. We also identified polymorphic epitopes that may escape host immunity, as some variants were not predicted as epitopes, suggesting that they may not be immunogenic regions. We present a set of epitopes that following in vitro validation provide a set of molecules to screen as potential vaccine candidates.
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Affiliation(s)
- Kevin Kariuki Wamae
- Centre for Biotechnology and Bioinformatics, University of Nairobi, Kenya
- KEMRI-Wellcome Trust Collaborative Programme,Kilifi, Kenya; P.O. Box 230, Kilifi – 80108, Kenya
| | - Lynette Isabella Ochola-Oyier
- Centre for Biotechnology and Bioinformatics, University of Nairobi, Kenya
- KEMRI-Wellcome Trust Collaborative Programme,Kilifi, Kenya; P.O. Box 230, Kilifi – 80108, Kenya
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26
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Epitope prediction for MSP119 protein in Plasmodium yeolii using computational approaches. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s13721-016-0127-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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27
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Ganeshan H, Kusi KA, Anum D, Hollingdale MR, Peters B, Kim Y, Tetteh JKA, Ofori MF, Gyan BA, Koram KA, Huang J, Belmonte M, Banania JG, Dodoo D, Villasante E, Sedegah M. Measurement of ex vivo ELISpot interferon-gamma recall responses to Plasmodium falciparum AMA1 and CSP in Ghanaian adults with natural exposure to malaria. Malar J 2016; 15:55. [PMID: 26830334 PMCID: PMC4736649 DOI: 10.1186/s12936-016-1098-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 01/12/2016] [Indexed: 12/17/2022] Open
Abstract
Background Malaria eradication requires a concerted approach involving all available control tools, and an effective vaccine would complement these efforts. An effective malaria vaccine should be able to induce protective immune responses in a genetically diverse population. Identification of immunodominant T cell epitopes will assist in determining if candidate vaccines will be immunogenic in malaria-endemic areas. This study therefore investigated whether class I-restricted T cell epitopes of two leading malaria vaccine antigens, Plasmodium falciparum circumsporozoite protein (CSP) and apical membrane antigen-1 (AMA1), could recall T cell interferon-γ responses from naturally exposed subjects using ex vivo ELISpot assays. Methods Thirty-five subjects aged between 24 and 43 years were recruited from a malaria-endemic urban community of Ghana in 2011, and their peripheral blood mononuclear cells (PBMCs) were tested in ELISpot IFN-γ assays against overlapping 15mer peptide pools spanning the entire CSP and AMA1 antigens, and 9–10mer peptide epitope mixtures that included previously identified and/or predicted human leukocyte antigen (HLA) class 1-restricted epitopes from same two antigens. Results For CSP, 26 % of subjects responded to at least one of the nine 15mer peptide pools whilst 17 % responded to at least one of the five 9–10mer HLA-restricted epitope mixtures. For AMA1, 63 % of subjects responded to at least one of the 12 AMA1 15mer peptide pools and 51 % responded to at least one of the six 9–10mer HLA-restricted epitope mixtures. Following analysis of data from the two sets of peptide pools, along with bioinformatics predictions of class I-restricted epitopes and the HLA supertypes expressed by a subset of study subjects, peptide pools that may contain epitopes recognized by multiple HLA supertypes were identified. Collectively, these results suggest that natural transmission elicits ELISpot IFN-γ activities to class 1-restricted epitopes that are largely HLA-promiscuous. Conclusions These results generally demonstrate that CSP and AMA1 peptides recalled ELISpot IFN-γ responses from naturally exposed individuals and that both CSP and AMA1 contain diverse class 1-restricted epitopes that are HLA-promiscuous and are widely recognized in this population. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1098-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Harini Ganeshan
- Malaria Department, Naval Medical Research Center, Silver Spring, MD, USA.
| | - Kwadwo A Kusi
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.
| | - Dorothy Anum
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.
| | | | - Bjoern Peters
- La Jolla Institute for Allergy and Immunology, La Jolla, San Diego, CA, USA.
| | - Yohan Kim
- La Jolla Institute for Allergy and Immunology, La Jolla, San Diego, CA, USA.
| | - John K A Tetteh
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.
| | - Michael F Ofori
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.
| | - Ben A Gyan
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.
| | - Kwadwo A Koram
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.
| | - Jun Huang
- Malaria Department, Naval Medical Research Center, Silver Spring, MD, USA.
| | - Maria Belmonte
- Malaria Department, Naval Medical Research Center, Silver Spring, MD, USA.
| | - Jo Glenna Banania
- Malaria Department, Naval Medical Research Center, Silver Spring, MD, USA.
| | - Daniel Dodoo
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.
| | - Eileen Villasante
- Malaria Department, Naval Medical Research Center, Silver Spring, MD, USA.
| | - Martha Sedegah
- Malaria Department, Naval Medical Research Center, Silver Spring, MD, USA.
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28
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Large screen approaches to identify novel malaria vaccine candidates. Vaccine 2015; 33:7496-505. [PMID: 26428458 DOI: 10.1016/j.vaccine.2015.09.059] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 09/07/2015] [Accepted: 09/15/2015] [Indexed: 11/20/2022]
Abstract
Until recently, malaria vaccine development efforts have focused almost exclusively on a handful of well characterized Plasmodium falciparum antigens. Despite dedicated work by many researchers on different continents spanning more than half a century, a successful malaria vaccine remains elusive. Sequencing of the P. falciparum genome has revealed more than five thousand genes, providing the foundation for systematic approaches to discover candidate vaccine antigens. We are taking advantage of this wealth of information to discover new antigens that may be more effective vaccine targets. Herein, we describe different approaches to large-scale screening of the P. falciparum genome to identify targets of either antibody responses or T cell responses using human specimens collected in Controlled Human Malaria Infections (CHMI) or under conditions of natural exposure in the field. These genome, proteome and transcriptome based approaches offer enormous potential for the development of an efficacious malaria vaccine.
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29
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Proietti C, Doolan DL. The case for a rational genome-based vaccine against malaria. Front Microbiol 2015; 5:741. [PMID: 25657640 PMCID: PMC4302942 DOI: 10.3389/fmicb.2014.00741] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 12/06/2014] [Indexed: 12/22/2022] Open
Abstract
Historically, vaccines have been designed to mimic the immunity induced by natural exposure to the target pathogen, but this approach has not been effective for any parasitic pathogen of humans or complex pathogens that cause chronic disease in humans, such as Plasmodium. Despite intense efforts by many laboratories around the world on different aspects of Plasmodium spp. molecular and cell biology, epidemiology and immunology, progress towards the goal of an effective malaria vaccine has been disappointing. The premise of rational vaccine design is to induce the desired immune response against the key pathogen antigens or epitopes targeted by protective immune responses. We advocate that development of an optimally efficacious malaria vaccine will need to improve on nature, and that this can be accomplished by rational vaccine design facilitated by mining genomic, proteomic and transcriptomic datasets in the context of relevant biological function. In our opinion, modern genome-based rational vaccine design offers enormous potential above and beyond that of whole-organism vaccines approaches established over 200 years ago where immunity is likely suboptimal due to the many genetic and immunological host-parasite adaptations evolved to allow the Plasmodium parasite to coexist in the human host, and which are associated with logistic and regulatory hurdles for production and delivery.
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Affiliation(s)
- Carla Proietti
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute Brisbane, QLD, Australia
| | - Denise L Doolan
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute Brisbane, QLD, Australia
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30
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A phase Ia study to assess the safety and immunogenicity of new malaria vaccine candidates ChAd63 CS administered alone and with MVA CS. PLoS One 2014; 9:e115161. [PMID: 25522180 PMCID: PMC4270740 DOI: 10.1371/journal.pone.0115161] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 11/16/2014] [Indexed: 01/23/2023] Open
Abstract
Background Plasmodium falciparum (P. falciparum) malaria remains a significant cause of mortality and morbidity throughout the world. Development of an effective vaccine would be a key intervention to reduce the considerable social and economic impact of malaria. Methodology We conducted a Phase Ia, non-randomized, clinical trial in 24 healthy, malaria-naïve adults of the chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) replication-deficient viral vectored vaccines encoding the circumsporozoite protein (CS) of P. falciparum. Results ChAd63-MVA CS administered in a heterologous prime-boost regime was shown to be safe and immunogenic, inducing high-level T cell responses to CS. With a priming ChAd63 CS dose of 5×109 vp responses peaked at a mean of 1947 SFC/million PBMC (median 1524) measured by ELIspot 7 days after the MVA boost and showed a mixed CD4+/CD8+ phenotype. With a higher priming dose of ChAd63 CS dose 5×1010 vp T cell responses did not increase (mean 1659 SFC/million PBMC, median 1049). Serum IgG responses to CS were modest and peaked at day 14 post ChAd63 CS (median antibody concentration for all groups at day 14 of 1.3 µg/ml (range 0–11.9), but persisted throughout late follow-up (day 140 median antibody concentration groups 1B & 2B 0.9 µg/ml (range 0–4.7). Conclusions ChAd63-MVA is a safe and highly immunogenic delivery platform for the CS antigen in humans which warrants efficacy testing. Trial Registration ClinicalTrials.gov NCT01450280
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Noe AR, Espinosa D, Li X, Coelho-dos-Reis JGA, Funakoshi R, Giardina S, Jin H, Retallack DM, Haverstock R, Allen JR, Vedvick TS, Fox CB, Reed SG, Ayala R, Roberts B, Winram SB, Sacci J, Tsuji M, Zavala F, Gutierrez GM. A full-length Plasmodium falciparum recombinant circumsporozoite protein expressed by Pseudomonas fluorescens platform as a malaria vaccine candidate. PLoS One 2014; 9:e107764. [PMID: 25247295 PMCID: PMC4172688 DOI: 10.1371/journal.pone.0107764] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 08/14/2014] [Indexed: 11/19/2022] Open
Abstract
The circumsporozoite protein (CSP) of Plasmodium falciparum is a major surface protein, which forms a dense coat on the sporozoite's surface. Preclinical research on CSP and clinical evaluation of a CSP fragment-based RTS, S/AS01 vaccine have demonstrated a modest degree of protection against P. falciparum, mediated in part by humoral immunity and in part by cell-mediated immunity. Given the partial protective efficacy of the RTS, S/AS01 vaccine in a recent Phase 3 trial, further improvement of CSP-based vaccines is crucial. In this report, we describe the preclinical development of a full-length, recombinant CSP (rCSP)-based vaccine candidate against P. falciparum malaria suitable for current Good Manufacturing Practice (cGMP) production. Utilizing a novel high-throughput Pseudomonas fluorescens expression platform, we demonstrated greater efficacy of full-length rCSP as compared to N-terminally truncated versions, rapidly down-selected a promising lead vaccine candidate, and developed a high-yield purification process to express immunologically active, intact antigen for clinical trial material production. The rCSP, when formulated with various adjuvants, induced antigen-specific antibody responses as measured by enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assay (IFA), as well as CD4+ T-cell responses as determined by ELISpot. The adjuvanted rCSP vaccine conferred protection in mice when challenged with transgenic P. berghei sporozoites containing the P. falciparum repeat region of CSP. Furthermore, heterologous prime/boost regimens with adjuvanted rCSP and an adenovirus type 35-vectored CSP (Ad35CS) showed modest improvements in eliciting CSP-specific T-cell responses and anti-malarial protection, depending on the order of vaccine delivery. Collectively, these data support the importance of further clinical development of adjuvanted rCSP, either as a stand-alone product or as one of the components in a heterologous prime/boost strategy, ultimately acting as an effective vaccine candidate for the mitigation of P. falciparum-induced malaria.
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Affiliation(s)
- Amy R. Noe
- Leidos Inc., Frederick, Maryland, United States of America
| | - Diego Espinosa
- Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Xiangming Li
- HIV and Malaria Vaccine Program, Aaron Diamond AIDS Research Center, Affiliate of The Rockefeller University, New York, New York, United States of America
| | - Jordana G. A. Coelho-dos-Reis
- HIV and Malaria Vaccine Program, Aaron Diamond AIDS Research Center, Affiliate of The Rockefeller University, New York, New York, United States of America
| | - Ryota Funakoshi
- HIV and Malaria Vaccine Program, Aaron Diamond AIDS Research Center, Affiliate of The Rockefeller University, New York, New York, United States of America
| | - Steve Giardina
- Leidos Inc., Frederick, Maryland, United States of America
| | - Hongfan Jin
- Pfenex Inc., San Diego, California, United States of America
| | | | - Ryan Haverstock
- Pfenex Inc., San Diego, California, United States of America
| | | | - Thomas S. Vedvick
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Christopher B. Fox
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Steven G. Reed
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Ramses Ayala
- Leidos Inc., Frederick, Maryland, United States of America
| | - Brian Roberts
- Leidos Inc., Frederick, Maryland, United States of America
| | | | - John Sacci
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Moriya Tsuji
- HIV and Malaria Vaccine Program, Aaron Diamond AIDS Research Center, Affiliate of The Rockefeller University, New York, New York, United States of America
| | - Fidel Zavala
- Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
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Doolan DL, Apte SH, Proietti C. Genome-based vaccine design: the promise for malaria and other infectious diseases. Int J Parasitol 2014; 44:901-13. [PMID: 25196370 DOI: 10.1016/j.ijpara.2014.07.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 01/08/2023]
Abstract
Vaccines are one of the most effective interventions to improve public health, however, the generation of highly effective vaccines for many diseases has remained difficult. Three chronic diseases that characterise these difficulties include malaria, tuberculosis and HIV, and they alone account for half of the global infectious disease burden. The whole organism vaccine approach pioneered by Jenner in 1796 and refined by Pasteur in 1857 with the "isolate, inactivate and inject" paradigm has proved highly successful for many viral and bacterial pathogens causing acute disease but has failed with respect to malaria, tuberculosis and HIV as well as many other diseases. A significant advance of the past decade has been the elucidation of the genomes, proteomes and transcriptomes of many pathogens. This information provides the foundation for new 21st Century approaches to identify target antigens for the development of vaccines, drugs and diagnostic tests. Innovative genome-based vaccine strategies have shown potential for a number of challenging pathogens, including malaria. We advocate that genome-based rational vaccine design will overcome the problem of poorly immunogenic, poorly protective vaccines that has plagued vaccine developers for many years.
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Affiliation(s)
- Denise L Doolan
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia.
| | - Simon H Apte
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Carla Proietti
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
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Terry FE, Moise L, Martin RF, Torres M, Pilotte N, Williams SA, De Groot AS. Time for T? Immunoinformatics addresses vaccine design for neglected tropical and emerging infectious diseases. Expert Rev Vaccines 2014; 14:21-35. [PMID: 25193104 PMCID: PMC4743591 DOI: 10.1586/14760584.2015.955478] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Vaccines have been invaluable for global health, saving lives and reducing healthcare costs, while also raising the quality of human life. However, newly emerging infectious diseases (EID) and more well-established tropical disease pathogens present complex challenges to vaccine developers; in particular, neglected tropical diseases, which are most prevalent among the world's poorest, include many pathogens with large sizes, multistage life cycles and a variety of nonhuman vectors. EID such as MERS-CoV and H7N9 are highly pathogenic for humans. For many of these pathogens, while their genomes are available, immune correlates of protection are currently unknown. These complexities make developing vaccines for EID and neglected tropical diseases all the more difficult. In this review, we describe the implementation of an immunoinformatics-driven approach to systematically search for key determinants of immunity in newly available genome sequence data and design vaccines. This approach holds promise for the development of 21st century vaccines, improving human health everywhere.
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Gandhi K, Thera MA, Coulibaly D, Traoré K, Guindo AB, Ouattara A, Takala-Harrison S, Berry AA, Doumbo OK, Plowe CV. Variation in the circumsporozoite protein of Plasmodium falciparum: vaccine development implications. PLoS One 2014; 9:e101783. [PMID: 24992338 PMCID: PMC4081809 DOI: 10.1371/journal.pone.0101783] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 06/11/2014] [Indexed: 11/18/2022] Open
Abstract
The malaria vaccine candidate RTS,S/AS01 is based on immunogenic regions of Plasmodium falciparum circumsporozoite protein (CSP) from the 3D7 reference strain and has shown modest efficacy against clinical disease in African children. It remains unclear what aspect(s) of the immune response elicited by this vaccine are protective. The goals of this study were to measure diversity in immunogenic regions of CSP, and to identify associations between polymorphism in CSP and the risk of P. falciparum infection and clinical disease. The present study includes data and samples from a prospective cohort study designed to measure incidence of malaria infection and disease in children in Bandiagara, Mali. A total of 769 parasite-positive blood samples corresponding to both acute clinical malaria episodes and asymptomatic infections experienced by 100 children were included in the study. Non-synonymous SNP data were generated by 454 sequencing for the T-cell epitopes, and repeat length data were generated for the B-cell epitopes of the cs gene. Cox proportional hazards models were used to determine the effect of sequence variation in consecutive infections occurring within individuals on the time to new infection and new clinical malaria episode. Diversity in the T-cell epitope-encoding regions Th2R and Th3R remained stable throughout seasons, between age groups and between clinical and asymptomatic infections with the exception of a higher proportion of 3D7 haplotypes found in the oldest age group. No associations between sequence variation and hazard of infection or clinical malaria were detected. The lack of association between sequence variation and hazard of infection or clinical malaria suggests that naturally acquired immunity to CSP may not be allele-specific.
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Affiliation(s)
- Kavita Gandhi
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Mahamadou A. Thera
- Malaria Research and Training Center, University of Science, Techniques and Technology, Bamako, Mali
| | - Drissa Coulibaly
- Malaria Research and Training Center, University of Science, Techniques and Technology, Bamako, Mali
| | - Karim Traoré
- Malaria Research and Training Center, University of Science, Techniques and Technology, Bamako, Mali
| | - Ando B. Guindo
- Malaria Research and Training Center, University of Science, Techniques and Technology, Bamako, Mali
| | - Amed Ouattara
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Shannon Takala-Harrison
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Andrea A. Berry
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Ogobara K. Doumbo
- Malaria Research and Training Center, University of Science, Techniques and Technology, Bamako, Mali
| | - Christopher V. Plowe
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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The immunodominant influenza A virus M158-66 cytotoxic T lymphocyte epitope exhibits degenerate class I major histocompatibility complex restriction in humans. J Virol 2014; 88:10613-23. [PMID: 24990997 DOI: 10.1128/jvi.00855-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED Cytotoxic T lymphocytes recognizing conserved peptide epitopes are crucial for protection against influenza A virus (IAV) infection. The CD8 T cell response against the M158-66 (GILGFVFTL) matrix protein epitope is immunodominant when restricted by HLA-A*02, a major histocompatibility complex (MHC) molecule expressed by approximately half of the human population. Here we report that the GILGFVFTL peptide is restricted by multiple HLA-C*08 alleles as well. We observed that M158-66 was able to elicit cytotoxic T lymphocyte (CTL) responses in both HLA-A*02- and HLA-C*08-positive individuals and that GILGFVFTL-specific CTLs in individuals expressing both restriction elements were distinct and not cross-reactive. The crystal structure of GILGFVFTL-HLA-C*08:01 was solved at 1.84 Å, and comparison with the known GILGFVFTL-HLA-A*02:01 structure revealed that the antigen bound both complexes in near-identical conformations, accommodated by binding pockets shaped from shared as well as unique residues. This discovery of degenerate peptide presentation by both HLA-A and HLA-C allelic variants eliciting unique CTL responses to IAV infection contributes fundamental knowledge with important implications for vaccine development strategies. IMPORTANCE The presentation of influenza A virus peptides to elicit immunity is thought to be narrowly restricted, with a single peptide presented by a specific HLA molecule. In this study, we show that the same influenza A virus peptide can be more broadly presented by both HLA-A and HLA-C molecules. This discovery may help to explain the differences in immunity to influenza A virus between individuals and populations and may also aid in the design of vaccines.
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The whole parasite, pre-erythrocytic stage approach to malaria vaccine development: a review. Curr Opin Infect Dis 2014; 26:420-8. [PMID: 23982233 DOI: 10.1097/qco.0000000000000002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The whole sporozoite (SPZ) vaccine platform provides the only established approach for inducing high-level sustained protective immunity in humans against malaria. We introduce this platform, highlight literature published since 2011, and discuss the challenges of further development. RECENT FINDINGS There are three major approaches to development of a whole parasite vaccine to prevent malaria infection using the SPZ platform: radiation-attenuated sporozoites (irrSPZ), chemoprophylaxis with infectious sporozoites (CPS), and genetically attenuated parasites (GAPs). In all three, SPZ are administered to the vaccinee. All three protect animals against infection when administered by injection with a needle and syringe, and irrSPZ and CPS protect against Plasmodium falciparum malaria in humans when P. falciparum SPZ (PfSPZ) are administered by mosquito bite. Metabolically active, nonreplicating (radiation attenuated) aseptic, purified, cryopreserved PfSPZ (PfSPZ Vaccine), and infectious, aseptic, purified, cryopreserved PfSPZ administered with chemoprophylaxis (PfSPZ-CVac approach) administered by needle and syringe have entered clinical trials. Preliminary data indicate that the PfSPZ Vaccine is safe, well tolerated and highly protective when administered intravenously. SUMMARY With proof-of-concept now established for high-grade protection induced by parenteral administration of a whole sporozoite vaccine, pathways for further development are currently being defined. Demonstration of high-level, durable, cross-strain P. falciparum protection would set the stage for licensure of a vaccine that could lead to dramatic reductions in malaria morbidity and mortality, and eventually elimination of this ancient scourge.
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Ohashi J, Suzuki Y, Naka I, Hananantachai H, Patarapotikul J. Diversifying selection on the thrombospondin-related adhesive protein (TRAP) gene of Plasmodium falciparum in Thailand. PLoS One 2014; 9:e90522. [PMID: 24587387 PMCID: PMC3938765 DOI: 10.1371/journal.pone.0090522] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 02/02/2014] [Indexed: 12/04/2022] Open
Abstract
Sporozoites of Plasmodium falciparum are transmitted to human hosts by Anopheles mosquitoes. Thrombospondin-related adhesive protein (TRAP) is expressed in sporozoites and plays a crucial role in sporozoite gliding and invasion of human hepatocytes. A previous study showed that the TRAP gene has been subjected to balancing selection in the Gambian P. falciparum population. To further study the molecular evolution of the TRAP gene in Plasmodium falciparum, we investigated TRAP polymorphisms in P. falciparum isolates from Suan Phueng District in Ratchaburi Province, Thailand. The analysis of the entire TRAP coding sequences in 32 isolates identified a total of 39 single nucleotide polymorphisms (SNPs), which comprised 37 nonsynonymous and two synonymous SNPs. McDonald–Kreitman test showed that the ratio of the number of nonsynonymous to synonymous polymorphic sites within P. falciparum was significantly higher than that of the number of nonsynonymous to synonymous fixed sites between P. falciparum and P. reichenowi. Furthermore, the rate of nonsynonymous substitution was significantly higher than that of synonymous substitution within Thai P. falciparum. These results indicate that the TRAP gene has been subject to diversifying selection in the Thai P. falciparum population as well as the Gambian P. falciparum population. Comparison of our P. falciparum isolates with those from another region of Thailand (Tak province, Thailand) revealed that TRAP was highly differentiated between geographically close regions. This rapid diversification seems to reflect strong recent positive selection on TRAP. Our results suggest that the TRAP molecule is a major target of the human immune response to pre-erythrocytic stages of P. falciparum.
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Affiliation(s)
- Jun Ohashi
- Molecular and Genetic Epidemiology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
- * E-mail:
| | - Yuji Suzuki
- Molecular and Genetic Epidemiology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Izumi Naka
- Molecular and Genetic Epidemiology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Hathairad Hananantachai
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jintana Patarapotikul
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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38
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Sheehy SH, Spencer AJ, Douglas AD, Sim BKL, Longley RJ, Edwards NJ, Poulton ID, Kimani D, Williams AR, Anagnostou NA, Roberts R, Kerridge S, Voysey M, James ER, Billingsley PF, Gunasekera A, Lawrie AM, Hoffman SL, Hill AVS. Optimising Controlled Human Malaria Infection Studies Using Cryopreserved P. falciparum Parasites Administered by Needle and Syringe. PLoS One 2013; 8:e65960. [PMID: 23823332 PMCID: PMC3688861 DOI: 10.1371/journal.pone.0065960] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 04/29/2013] [Indexed: 11/18/2022] Open
Abstract
Background Controlled human malaria infection (CHMI) studies have become a routine tool to evaluate efficacy of candidate anti-malarial drugs and vaccines. To date, CHMI trials have mostly been conducted using the bite of infected mosquitoes, restricting the number of trial sites that can perform CHMI studies. Aseptic, cryopreserved P. falciparum sporozoites (PfSPZ Challenge) provide a potentially more accurate, reproducible and practical alternative, allowing a known number of sporozoites to be administered simply by injection. Methodology We sought to assess the infectivity of PfSPZ Challenge administered in different dosing regimens to malaria-naive healthy adults (n = 18). Six participants received 2,500 sporozoites intradermally (ID), six received 2,500 sporozoites intramuscularly (IM) and six received 25,000 sporozoites IM. Findings Five out of six participants receiving 2,500 sporozoites ID, 3/6 participants receiving 2,500 sporozoites IM and 6/6 participants receiving 25,000 sporozoites IM were successfully infected. The median time to diagnosis was 13.2, 17.8 and 12.7 days for 2,500 sporozoites ID, 2,500 sporozoites IM and 25,000 sporozoites IM respectively (Kaplan Meier method; p = 0.024 log rank test). Conclusions 2,500 sporozoites ID and 25,000 sporozoites IM have similar infectivities. Given the dose response in infectivity seen with IM administration, further work should evaluate increasing doses of PfSPZ Challenge IM to identify a dosing regimen that reliably infects 100% of participants. Trial Registration ClinicalTrials.gov NCT01465048
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Affiliation(s)
- Susanne H. Sheehy
- Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Oxford, United Kingdom
- The Jenner Institute Laboratories, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | | | | | - B. Kim Lee Sim
- Sanaria Inc., Rockville, Maryland, United States of America
| | - Rhea J. Longley
- The Jenner Institute Laboratories, University of Oxford, Oxford, United Kingdom
| | - Nick J. Edwards
- The Jenner Institute Laboratories, University of Oxford, Oxford, United Kingdom
| | - Ian D. Poulton
- Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | - Domtila Kimani
- Centre for Geographical Medical Research (Coast), Kenya Medical Research Institute, Kilifi, Kenya
| | - Andrew R. Williams
- The Jenner Institute Laboratories, University of Oxford, Oxford, United Kingdom
| | - Nicholas A. Anagnostou
- Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | - Rachel Roberts
- Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | - Simon Kerridge
- Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | - Merryn Voysey
- Centre for Statistics in Medicine, University of Oxford, Oxford, United Kingdom
| | - Eric R. James
- Sanaria Inc., Rockville, Maryland, United States of America
| | | | | | - Alison M. Lawrie
- Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Adrian V. S. Hill
- The Jenner Institute Laboratories, University of Oxford, Oxford, United Kingdom
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Sedegah M, Kim Y, Ganeshan H, Huang J, Belmonte M, Abot E, Banania JG, Farooq F, McGrath S, Peters B, Sette A, Soisson L, Diggs C, Doolan DL, Tamminga C, Villasante E, Hollingdale MR, Richie TL. Identification of minimal human MHC-restricted CD8+ T-cell epitopes within the Plasmodium falciparum circumsporozoite protein (CSP). Malar J 2013; 12:185. [PMID: 23738590 PMCID: PMC3683343 DOI: 10.1186/1475-2875-12-185] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 05/23/2013] [Indexed: 01/14/2023] Open
Abstract
Background Plasmodium falciparum circumsporozoite protein (CSP) is a leading malaria vaccine candidate antigen, known to elicit protective antibody responses in humans (RTS,S vaccine). Recently, a DNA prime / adenovirus (Ad) vector boost vaccine encoding CSP and a second P. falciparum antigen, apical membrane antigen-1, also elicited sterile protection, but in this case associated with interferon gamma ELISpot and CD8+ T cell but not antibody responses. The finding that CSP delivered by an appropriate vaccine platform likely elicits protective cell-mediated immunity provided a rationale for identifying class I-restricted epitopes within this leading vaccine candidate antigen. Methods Limited samples of peripheral blood mononuclear cells from clinical trials of the Ad vaccine were used to identify CD8+ T cell epitopes within pools of overlapping 15mer peptides spanning portions of CSP that stimulated recall responses. Computerized algorithms (NetMHC) predicted 17 minimal class I-restricted 9-10mer epitopes within fifteen 15mers positive in ELISpot assay using PBMC from 10 HLA-matched study subjects. Four additional epitopes were subsequently predicted using NetMHC, matched to other study subjects without initial 15mer ELISpot screening. Nine of the putative epitopes were synthesized and tested by ELISpot assay, and six of these nine were further tested for CD8+ T cell responses by ELISpot CD4+ and CD8+ T cell-depletion and flow cytometry assays for evidence of CD8+ T cell dependence. Results Each of the nine putative epitopes, all sequence-conserved, recalled responses from HLA-matched CSP-immunized research subjects. Four shorter sequences contained within these sequences were identified using NetMHC predictions and may have contributed to recall responses. Five (9-10mer) epitopes were confirmed to be targets of CD8+ T cell responses using ELISpot depletion and ICS assays. Two 9mers among these nine epitopes were each restricted by two HLA supertypes (A01/B07; A01A24/A24) and one 9mer was restricted by three HLA supertypes (A01A24/A24/B27) indicating that some CSP class I-restricted epitopes, like DR epitopes, may be HLA-promiscuous. Conclusions This study identified nine and confirmed five novel class I epitopes restricted by six HLA supertypes, suggesting that an adenovirus-vectored CSP vaccine would be immunogenic and potentially protective in genetically diverse populations.
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Affiliation(s)
- Martha Sedegah
- US Military Malaria Vaccine Program, Naval Medical Research Center, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
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40
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Duffy PE, Sahu T, Akue A, Milman N, Anderson C. Pre-erythrocytic malaria vaccines: identifying the targets. Expert Rev Vaccines 2013; 11:1261-80. [PMID: 23176657 DOI: 10.1586/erv.12.92] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Pre-erythrocytic malaria vaccines target Plasmodium during its sporozoite and liver stages, and can prevent progression to blood-stage disease, which causes a million deaths each year. Whole organism sporozoite vaccines induce sterile immunity in animals and humans and guide subunit vaccine development. A recombinant protein-in-adjuvant pre-erythrocytic vaccine called RTS,S reduces clinical malaria without preventing infection in field studies and additional antigens may be required to achieve sterile immunity. Although few vaccine antigens have progressed to human testing, new insights into parasite biology, expression profiles and immunobiology have offered new targets for intervention. Future advances require human trials of additional antigens, as well as platforms to induce the durable antibody and cellular responses including CD8(+) T cells that contribute to sterile protection.
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Affiliation(s)
- Patrick E Duffy
- Laboratory of Malaria Immunology & Vaccinology, Division of Intramural Research, NIAID, NIH, Rockville, MD, USA.
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41
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Patronov A, Doytchinova I. T-cell epitope vaccine design by immunoinformatics. Open Biol 2013; 3:120139. [PMID: 23303307 PMCID: PMC3603454 DOI: 10.1098/rsob.120139] [Citation(s) in RCA: 255] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Accepted: 12/11/2012] [Indexed: 01/08/2023] Open
Abstract
Vaccination is generally considered to be the most effective method of preventing infectious diseases. All vaccinations work by presenting a foreign antigen to the immune system in order to evoke an immune response. The active agent of a vaccine may be intact but inactivated ('attenuated') forms of the causative pathogens (bacteria or viruses), or purified components of the pathogen that have been found to be highly immunogenic. The increased understanding of antigen recognition at molecular level has resulted in the development of rationally designed peptide vaccines. The concept of peptide vaccines is based on identification and chemical synthesis of B-cell and T-cell epitopes which are immunodominant and can induce specific immune responses. The accelerating growth of bioinformatics techniques and applications along with the substantial amount of experimental data has given rise to a new field, called immunoinformatics. Immunoinformatics is a branch of bioinformatics dealing with in silico analysis and modelling of immunological data and problems. Different sequence- and structure-based immunoinformatics methods are reviewed in the paper.
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Affiliation(s)
| | - Irini Doytchinova
- Department of Chemistry, Faculty of Pharmacy, Medical University of Sofia, Sofia, Bulgaria
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42
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Richie TL. Malaria vaccines for travelers. Travel Med Infect Dis 2012; 2:193-210. [PMID: 17291981 DOI: 10.1016/j.tmaid.2004.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2004] [Accepted: 07/07/2004] [Indexed: 11/21/2022]
Affiliation(s)
- Thomas L Richie
- Naval Medical Research Center Malaria Program, 503 Robert Grant Avenue, Silver Spring, MD 20910-7500, USA
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43
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Apte SH, Groves PL, Skwarczynski M, Fujita Y, Chang C, Toth I, Doolan DL. Vaccination with lipid core peptides fails to induce epitope-specific T cell responses but confers non-specific protective immunity in a malaria model. PLoS One 2012; 7:e40928. [PMID: 22936972 PMCID: PMC3427299 DOI: 10.1371/journal.pone.0040928] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 06/15/2012] [Indexed: 11/29/2022] Open
Abstract
Vaccines against many pathogens for which conventional approaches have failed remain an unmet public health priority. Synthetic peptide-based vaccines offer an attractive alternative to whole protein and whole organism vaccines, particularly for complex pathogens that cause chronic infection. Previously, we have reported a promising lipid core peptide (LCP) vaccine delivery system that incorporates the antigen, carrier, and adjuvant in a single molecular entity. LCP vaccines have been used to deliver several peptide subunit-based vaccine candidates and induced high titre functional antibodies and protected against Group A streptococcus in mice. Herein, we have evaluated whether LCP constructs incorporating defined CD4+ and/or CD8+ T cell epitopes could induce epitope-specific T cell responses and protect against pathogen challenge in a rodent malaria model. We show that LCP vaccines failed to induce an expansion of antigen-specific CD8+ T cells following primary immunization or by boosting. We further demonstrated that the LCP vaccines induced a non-specific type 2 polarized cytokine response, rather than an epitope-specific canonical CD8+ T cell type 1 response. Cytotoxic responses of unknown specificity were also induced. These non-specific responses were able to protect against parasite challenge. These data demonstrate that vaccination with lipid core peptides fails to induce canonical epitope-specific T cell responses, at least in our rodent model, but can nonetheless confer non-specific protective immunity against Plasmodium parasite challenge.
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Affiliation(s)
- Simon H. Apte
- Infectious Diseases Programme, Queensland Institute of Medical Research, Herston, Queensland, Australia
| | - Penny L. Groves
- Infectious Diseases Programme, Queensland Institute of Medical Research, Herston, Queensland, Australia
| | - Mariusz Skwarczynski
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Yoshio Fujita
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Chenghung Chang
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
- School of Pharmacy, University of Queensland, St Lucia, Queensland, Australia
| | - Denise L. Doolan
- Infectious Diseases Programme, Queensland Institute of Medical Research, Herston, Queensland, Australia
- School of Medicine, University of Queensland, Herston, Queensland, Australia
- * E-mail:
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Weiss WR, Jiang CG. Protective CD8+ T lymphocytes in primates immunized with malaria sporozoites. PLoS One 2012; 7:e31247. [PMID: 22355349 PMCID: PMC3280278 DOI: 10.1371/journal.pone.0031247] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 01/05/2012] [Indexed: 11/26/2022] Open
Abstract
Live attenuated malaria vaccines are more potent than the recombinant protein, bacterial or viral platform vaccines that have been tested, and an attenuated sporozoite vaccine against falciparum malaria is being developed for humans. In mice, attenuated malaria sporozoite vaccines induce CD8+ T cells that kill parasites developing in the liver. We were curious to know if CD8+ T cells were also important in protecting primates against malaria. We immunized 9 rhesus monkeys with radiation attenuated Plasmodium knowlesi sporozoites, and found that 5 did not develop blood stage infections after challenge with live sporozoites. We then injected 4 of these protected monkeys with cM-T807, a monoclonal antibody to the CD8 molecule which depletes T cells. The fifth monkey received equivalent doses of normal IgG. In 3 of the 4 monkeys receiving cM-T807 circulating CD8+ T cells were profoundly depleted. When re-challenged with live sporozoites all 3 of these depleted animals developed blood stage malaria. The fourth monkey receiving cM-T807 retained many circulating CD8+ T cells. This monkey, and the vaccinated monkey receiving normal IgG, did not develop blood stage malaria at re-challenge with live sporozoites. Animals were treated with antimalarial drugs and rested for 4 months. During this interval CD8+ T cells re-appeared in the circulation of the depleted monkeys. When all vaccinated animals received a third challenge with live sporozoites, all 5 monkeys were once again protected and did not develop blood stage malaria infections. These data indicate that CD8+ T cells are important effector cells protecting monkeys against malaria sporozoite infection. We believe that malaria vaccines which induce effector CD8+ T cells in humans will have the best chance of protecting against malaria.
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Affiliation(s)
- Walter R Weiss
- Infectious Disease Department, Naval Medical Research Center, Silver Spring, Maryland, United States of America.
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Sedegah M, Tamminga C, McGrath S, House B, Ganeshan H, Lejano J, Abot E, Banania GJ, Sayo R, Farooq F, Belmonte M, Manohar N, Richie NO, Wood C, Long CA, Regis D, Williams FT, Shi M, Chuang I, Spring M, Epstein JE, Mendoza-Silveiras J, Limbach K, Patterson NB, Bruder JT, Doolan DL, King CR, Soisson L, Diggs C, Carucci D, Dutta S, Hollingdale MR, Ockenhouse CF, Richie TL. Adenovirus 5-vectored P. falciparum vaccine expressing CSP and AMA1. Part A: safety and immunogenicity in seronegative adults. PLoS One 2011; 6:e24586. [PMID: 22003383 PMCID: PMC3189181 DOI: 10.1371/journal.pone.0024586] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 08/15/2011] [Indexed: 11/24/2022] Open
Abstract
Background Models of immunity to malaria indicate the importance of CD8+ T cell responses for targeting intrahepatic stages and antibodies for targeting sporozoite and blood stages. We designed a multistage adenovirus 5 (Ad5)-vectored Plasmodium falciparum malaria vaccine, aiming to induce both types of responses in humans, that was tested for safety and immunogenicity in a Phase 1 dose escalation trial in Ad5-seronegative volunteers. Methodology/Principal Findings The NMRC-M3V-Ad-PfCA vaccine combines two adenovectors encoding circumsporozoite protein (CSP) and apical membrane antigen-1 (AMA1). Group 1 (n = 6) healthy volunteers received one intramuscular injection of 2×10∧10 particle units (1×10∧10 each construct) and Group 2 (n = 6) a five-fold higher dose. Transient, mild to moderate adverse events were more pronounced with the higher dose. ELISpot responses to CSP and AMA1 peaked at 1 month, were higher in the low dose (geomean CSP = 422, AMA1 = 862 spot forming cells/million) than in the high dose (CSP = 154, p = 0.049, AMA1 = 423, p = 0.045) group and were still positive at 12 months in a number of volunteers. ELISpot depletion assays identified dependence on CD4+ or on both CD4+ and CD8+ T cells, with few responses dependent only on CD8+ T cells. Intracellular cytokine staining detected stronger CD8+ than CD4+ T cell IFN-γ responses (CSP p = 0.0001, AMA1 p = 0.003), but similar frequencies of multifunctional CD4+ and CD8+ T cells secreting two or more of IFN-γ, TNF-α or IL-2. Median fluorescence intensities were 7–10 fold higher in triple than single secreting cells. Antibody responses were low but trended higher in the high dose group and did not inhibit growth of cultured P. falciparum blood stage parasites. Significance As found in other trials, adenovectored vaccines appeared safe and well-tolerated at doses up to 1×10∧11 particle units. This is the first demonstration in humans of a malaria vaccine eliciting strong CD8+ T cell IFN-γ responses. Trial Registration ClinicalTrials.govNCT00392015
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Affiliation(s)
- Martha Sedegah
- U.S. Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America.
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Tamminga C, Sedegah M, Regis D, Chuang I, Epstein JE, Spring M, Mendoza-Silveiras J, McGrath S, Maiolatesi S, Reyes S, Steinbeiss V, Fedders C, Smith K, House B, Ganeshan H, Lejano J, Abot E, Banania GJ, Sayo R, Farooq F, Belmonte M, Murphy J, Komisar J, Williams J, Shi M, Brambilla D, Manohar N, Richie NO, Wood C, Limbach K, Patterson NB, Bruder JT, Doolan DL, King CR, Diggs C, Soisson L, Carucci D, Levine G, Dutta S, Hollingdale MR, Ockenhouse CF, Richie TL. Adenovirus-5-vectored P. falciparum vaccine expressing CSP and AMA1. Part B: safety, immunogenicity and protective efficacy of the CSP component. PLoS One 2011; 6:e25868. [PMID: 22003411 PMCID: PMC3189219 DOI: 10.1371/journal.pone.0025868] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Accepted: 09/12/2011] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND A protective malaria vaccine will likely need to elicit both cell-mediated and antibody responses. As adenovirus vaccine vectors induce both these responses in humans, a Phase 1/2a clinical trial was conducted to evaluate the efficacy of an adenovirus serotype 5-vectored malaria vaccine against sporozoite challenge. METHODOLOGY/PRINCIPAL FINDINGS NMRC-MV-Ad-PfC is an adenovirus vector encoding the Plasmodium falciparum 3D7 circumsporozoite protein (CSP). It is one component of a two-component vaccine NMRC-M3V-Ad-PfCA consisting of one adenovector encoding CSP and one encoding apical membrane antigen-1 (AMA1) that was evaluated for safety and immunogenicity in an earlier study (see companion paper, Sedegah et al). Fourteen Ad5 seropositive or negative adults received two doses of NMRC-MV-Ad-PfC sixteen weeks apart, at 1 x 1010 particle units per dose. The vaccine was safe and well tolerated. All volunteers developed positive ELISpot responses by 28 days after the first immunization (geometric mean 272 spot forming cells/million[sfc/m]) that declined during the following 16 weeks and increased after the second dose to levels that in most cases were less than the initial peak (geometric mean 119 sfc/m). CD8+ predominated over CD4+ responses, as in the first clinical trial. Antibody responses were poor and like ELISpot responses increased after the second immunization but did not exceed the initial peak. Pre-existing neutralizing antibodies (NAb) to Ad5 did not affect the immunogenicity of the first dose, but the fold increase in NAb induced by the first dose was significantly associated with poorer antibody responses after the second dose, while ELISpot responses remained unaffected. When challenged by the bite of P. falciparum-infected mosquitoes, two of 11 volunteers showed a delay in the time to patency compared to infectivity controls, but no volunteers were sterilely protected. SIGNIFICANCE The NMRC-MV-Ad-PfC vaccine expressing CSP was safe and well tolerated given as two doses, but did not provide sterile protection. TRIAL REGISTRATION ClinicalTrials.gov NCT00392015.
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Affiliation(s)
- Cindy Tamminga
- U.S. Military Malaria Vaccine Program, Naval Medical Research Center, Silver Spring, Maryland, United States of America.
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Rao X, Hoof I, Fontaine Costa AICA, van Baarle D, Keşmir C. HLA class I allele promiscuity revisited. Immunogenetics 2011; 63:691-701. [PMID: 21695550 PMCID: PMC3190086 DOI: 10.1007/s00251-011-0552-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 06/10/2011] [Indexed: 12/02/2022]
Abstract
The peptide repertoire presented on human leukocyte antigen (HLA) class I molecules is largely determined by the structure of the peptide binding groove. It is expected that the molecules having similar grooves (i.e., belonging to the same supertype) might present similar/overlapping peptides. However, the extent of promiscuity among HLA class I ligands remains controversial: while in many studies T cell responses are detected against epitopes presented by alternative molecules across HLA class I supertypes and loci, peptide elution studies report minute overlaps between the peptide repertoires of even related HLA molecules. To get more insight into the promiscuous peptide binding by HLA molecules, we analyzed the HLA peptide binding data from the large epitope repository, Immune Epitope Database (IEDB), and further performed in silico analysis to estimate the promiscuity at the population level. Both analyses suggest that an unexpectedly large fraction of HLA ligands (>50%) bind two or more HLA molecules, often across supertype or even loci. These results suggest that different HLA class I molecules can nevertheless present largely overlapping peptide sets, and that “functional” HLA polymorphism on individual and population level is probably much lower than previously anticipated.
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Affiliation(s)
- Xiangyu Rao
- Theoretical Biology and Bioinformatics, Utrecht University, Padualaan 8, 3584CH Utrecht, The Netherlands
| | - Ilka Hoof
- Theoretical Biology and Bioinformatics, Utrecht University, Padualaan 8, 3584CH Utrecht, The Netherlands
| | | | - Debbie van Baarle
- Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Can Keşmir
- Theoretical Biology and Bioinformatics, Utrecht University, Padualaan 8, 3584CH Utrecht, The Netherlands
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Dodoo D, Hollingdale MR, Anum D, Koram KA, Gyan B, Akanmori BD, Ocran J, Adu-Amankwah S, Geneshan H, Abot E, Legano J, Banania G, Sayo R, Brambilla D, Kumar S, Doolan DL, Rogers WO, Epstein J, Richie TL, Sedegah M. Measuring naturally acquired immune responses to candidate malaria vaccine antigens in Ghanaian adults. Malar J 2011; 10:168. [PMID: 21689436 PMCID: PMC3132199 DOI: 10.1186/1475-2875-10-168] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 06/20/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To prepare field sites for malaria vaccine trials, it is important to determine baseline antibody and T cell responses to candidate malaria vaccine antigens. Assessing T cell responses is especially challenging, given genetic restriction, low responses observed in endemic areas, their variability over time, potential suppression by parasitaemia and the intrinsic variability of the assays. METHODS In Part A of this study, antibody titres were measured in adults from urban and rural communities in Ghana to recombinant Plasmodium falciparum CSP, SSP2/TRAP, LSA1, EXP1, MSP1, MSP3 and EBA175 by ELISA, and to sporozoites and infected erythrocytes by IFA. Positive ELISA responses were determined using two methods. T cell responses to defined CD8 or CD4 T cell epitopes from CSP, SSP2/TRAP, LSA1 and EXP1 were measured by ex vivo IFN-γ ELISpot assays using HLA-matched Class I- and DR-restricted synthetic peptides. In Part B, the reproducibility of the ELISpot assay to CSP and AMA1 was measured by repeating assays of individual samples using peptide pools and low, medium or high stringency criteria for defining positive responses, and by comparing samples collected two weeks apart. RESULTS In Part A, positive antibody responses varied widely from 17%-100%, according to the antigen and statistical method, with blood stage antigens showing more frequent and higher magnitude responses. ELISA titres were higher in rural subjects, while IFA titres and the frequencies and magnitudes of ex vivo ELISpot activities were similar in both communities. DR-restricted peptides showed stronger responses than Class I-restricted peptides. In Part B, the most stringent statistical criteria gave the fewest, and the least stringent the most positive responses, with reproducibility slightly higher using the least stringent method when assays were repeated. Results varied significantly between the two-week time-points for many participants. CONCLUSIONS All participants were positive for at least one malaria protein by ELISA, with results dependent on the criteria for positivity. Likewise, ELISpot responses varied among participants, but were relatively reproducible by the three methods tested, especially the least stringent, when assays were repeated. However, results often differed between samples taken two weeks apart, indicating significant biological variability over short intervals.
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Affiliation(s)
- Daniel Dodoo
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
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Abstract
Malaria is a vector-borne infectious disease caused by unicellular parasites of the genus Plasmodium. These obligate intracellular parasites have the unique capacity to infect and replicate within erythrocytes, which are terminally differentiated host cells that lack antigen presentation pathways. Prior to the cyclic erythrocytic infections that cause the characteristic clinical symptoms of malaria, the parasite undergoes an essential and clinically silent expansion phase in the liver. By infecting privileged host cells, employing programs of complex life stage conversions and expressing varying immunodominant antigens, Plasmodium parasites have evolved mechanisms to downmodulate protective immune responses against ongoing and even future infections. Consequently, anti-malaria immunity develops only gradually over many years of repeated and multiple infections in endemic areas. The identification of immune correlates of protection among the abundant non-protective host responses remains a research priority. Understanding the molecular and immunological mechanisms of the crosstalk between the parasite and the host is a prerequisite for the rational discovery and development of a safe, affordable, and protective anti-malaria vaccine.
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Affiliation(s)
- Julius Clemence Hafalla
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
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Schwenk RJ, Richie TL. Protective immunity to pre-erythrocytic stage malaria. Trends Parasitol 2011; 27:306-14. [PMID: 21435951 DOI: 10.1016/j.pt.2011.02.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 02/14/2011] [Accepted: 02/14/2011] [Indexed: 01/23/2023]
Abstract
The development of a vaccine against malaria is a major research priority given the burden of disease, death and economic loss inflicted upon the tropical world by this parasite. Despite decades of effort, however, a vaccine remains elusive. The best candidate is a subunit vaccine termed RTS,S but this provides only partial protection against clinical disease. This review examines what is known about protective immunity against pre-erythrocytic stage malaria by considering the humoral and T cell-mediated immune responses that are induced by attenuated sporozoites and by the RTS,S vaccine. On the basis of these observations a set of research priorities are defined that are crucial for the development of a vaccine capable of inducing long-lasting and high-grade protection against malaria.
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Affiliation(s)
- Robert J Schwenk
- US Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Division of Malaria Vaccine Development, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA.
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