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Pissarra J, Dorkeld F, Loire E, Bonhomme V, Sereno D, Lemesre JL, Holzmuller P. SILVI, an open-source pipeline for T-cell epitope selection. PLoS One 2022; 17:e0273494. [PMID: 36070252 PMCID: PMC9451077 DOI: 10.1371/journal.pone.0273494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 08/09/2022] [Indexed: 11/18/2022] Open
Abstract
High-throughput screening of available genomic data and identification of potential antigenic candidates have promoted the development of epitope-based vaccines and therapeutics. Several immunoinformatic tools are available to predict potential epitopes and other immunogenicity-related features, yet it is still challenging and time-consuming to compare and integrate results from different algorithms. We developed the R script SILVI (short for: from in silico to in vivo), to assist in the selection of the potentially most immunogenic T-cell epitopes from Human Leukocyte Antigen (HLA)-binding prediction data. SILVI merges and compares data from available HLA-binding prediction servers, and integrates additional relevant information of predicted epitopes, namely BLASTp alignments with host proteins and physical-chemical properties. The two default criteria applied by SILVI and additional filtering allow the fast selection of the most conserved, promiscuous, strong binding T-cell epitopes. Users may adapt the script at their discretion as it is written in open-source R language. To demonstrate the workflow and present selection options, SILVI was used to integrate HLA-binding prediction results of three example proteins, from viral, bacterial and parasitic microorganisms, containing validated epitopes included in the Immune Epitope Database (IEDB), plus the Human Papillomavirus (HPV) proteome. Applying different filters on predicted IC50, hydrophobicity and mismatches with host proteins allows to significantly reduce the epitope lists with favourable sensitivity and specificity to select immunogenic epitopes. We contemplate SILVI will assist T-cell epitope selections and can be continuously refined in a community-driven manner, helping the improvement and design of peptide-based vaccines or immunotherapies. SILVI development version is available at: github.com/JoanaPissarra/SILVI2020 and https://doi.org/10.5281/zenodo.6865909.
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Affiliation(s)
- Joana Pissarra
- UMR INTERTRYP, IRD, CIRAD, University of Montpellier (I-MUSE), Montpellier, France
- * E-mail:
| | - Franck Dorkeld
- UMR CBGP, INRAE, CIRAD, IRD, Montpellier SupAgro, University of Montpellier (I-MUSE), Montpellier, France
| | - Etienne Loire
- UMR ASTRE, CIRAD, INRAE, University of Montpellier (I-MUSE), Montpellier, France
| | - Vincent Bonhomme
- ISEM, CNRS, EPHE, IRD, University of Montpellier (I-MUSE), Montpellier, France
| | - Denis Sereno
- UMR INTERTRYP, IRD, CIRAD, University of Montpellier (I-MUSE), Montpellier, France
| | - Jean-Loup Lemesre
- UMR INTERTRYP, IRD, CIRAD, University of Montpellier (I-MUSE), Montpellier, France
| | - Philippe Holzmuller
- UMR ASTRE, CIRAD, INRAE, University of Montpellier (I-MUSE), Montpellier, France
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Moncunill G, Scholzen A, Mpina M, Nhabomba A, Hounkpatin AB, Osaba L, Valls R, Campo JJ, Sanz H, Jairoce C, Williams NA, Pasini EM, Arteta D, Maynou J, Palacios L, Duran-Frigola M, Aponte JJ, Kocken CHM, Agnandji ST, Mas JM, Mordmüller B, Daubenberger C, Sauerwein R, Dobaño C. Antigen-stimulated PBMC transcriptional protective signatures for malaria immunization. Sci Transl Med 2020; 12:12/543/eaay8924. [DOI: 10.1126/scitranslmed.aay8924] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 11/26/2019] [Accepted: 04/15/2020] [Indexed: 02/06/2023]
Abstract
Identifying immune correlates of protection and mechanisms of immunity accelerates and streamlines the development of vaccines. RTS,S/AS01E, the most clinically advanced malaria vaccine, has moderate efficacy in African children. In contrast, immunization with sporozoites under antimalarial chemoprophylaxis (CPS immunization) can provide 100% sterile protection in naïve adults. We used systems biology approaches to identifying correlates of vaccine-induced immunity based on transcriptomes of peripheral blood mononuclear cells from individuals immunized with RTS,S/AS01E or chemoattenuated sporozoites stimulated with parasite antigens in vitro. Specifically, we used samples of individuals from two age cohorts and three African countries participating in an RTS,S/AS01E pediatric phase 3 trial and malaria-naïve individuals participating in a CPS trial. We identified both preimmunization and postimmunization transcriptomic signatures correlating with protection. Signatures were validated in independent children and infants from the RTS,S/AS01E phase 3 trial and individuals from an independent CPS trial with high accuracies (>70%). Transcription modules revealed interferon, NF-κB, Toll-like receptor (TLR), and monocyte-related signatures associated with protection. Preimmunization signatures suggest that priming the immune system before vaccination could potentially improve vaccine immunogenicity and efficacy. Last, signatures of protection could be useful to determine efficacy in clinical trials, accelerating vaccine candidate testing. Nevertheless, signatures should be tested more extensively across multiple cohorts and trials to demonstrate their universal predictive capacity.
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Affiliation(s)
- Gemma Moncunill
- ISGlobal, Hospital Clínic–Universitat de Barcelona, E-08036 Barcelona, Catalonia, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929 Maputo, Mozambique
| | - Anja Scholzen
- Department of Medical Microbiology, Radboud University Medical Center, 6500 HB Nijmegen, Netherlands
| | - Maximillian Mpina
- Ifakara Health Institute, Bagamoyo Research and Training Centre. P.O. Box 74, Bagamoyo, Tanzania
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Augusto Nhabomba
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929 Maputo, Mozambique
| | - Aurore Bouyoukou Hounkpatin
- Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242 Lambaréné, Gabon
- Institute of Tropical Medicine and German Center for Infection Research, University of Tübingen, Wilhelmstraße 27, D-72074 Tübingen, Germany
| | - Lourdes Osaba
- Progenika Biopharma. A Grifols Company, S.A., 48160 Derio, Vizcaya, Spain
| | | | - Joseph J. Campo
- ISGlobal, Hospital Clínic–Universitat de Barcelona, E-08036 Barcelona, Catalonia, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929 Maputo, Mozambique
| | - Hèctor Sanz
- ISGlobal, Hospital Clínic–Universitat de Barcelona, E-08036 Barcelona, Catalonia, Spain
| | - Chenjerai Jairoce
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929 Maputo, Mozambique
| | - Nana Aba Williams
- ISGlobal, Hospital Clínic–Universitat de Barcelona, E-08036 Barcelona, Catalonia, Spain
| | - Erica M. Pasini
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, Netherlands
| | - David Arteta
- Progenika Biopharma. A Grifols Company, S.A., 48160 Derio, Vizcaya, Spain
| | - Joan Maynou
- Progenika Biopharma. A Grifols Company, S.A., 48160 Derio, Vizcaya, Spain
| | - Lourdes Palacios
- Progenika Biopharma. A Grifols Company, S.A., 48160 Derio, Vizcaya, Spain
| | - Miquel Duran-Frigola
- Institute for Research in Biomedicine (IRB Barcelona). The Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
| | - John J. Aponte
- ISGlobal, Hospital Clínic–Universitat de Barcelona, E-08036 Barcelona, Catalonia, Spain
| | - Clemens H. M. Kocken
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, Netherlands
| | - Selidji Todagbe Agnandji
- Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242 Lambaréné, Gabon
- Institute of Tropical Medicine and German Center for Infection Research, University of Tübingen, Wilhelmstraße 27, D-72074 Tübingen, Germany
| | | | - Benjamin Mordmüller
- Institute of Tropical Medicine and German Center for Infection Research, University of Tübingen, Wilhelmstraße 27, D-72074 Tübingen, Germany
| | - Claudia Daubenberger
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Robert Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, 6500 HB Nijmegen, Netherlands
| | - Carlota Dobaño
- ISGlobal, Hospital Clínic–Universitat de Barcelona, E-08036 Barcelona, Catalonia, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929 Maputo, Mozambique
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3
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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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4
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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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5
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Lima-Junior JDC, Morgado FN, Conceição-Silva F. How Can Elispot Add Information to Improve Knowledge on Tropical Diseases? Cells 2017; 6:cells6040031. [PMID: 28961208 PMCID: PMC5755491 DOI: 10.3390/cells6040031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 09/12/2017] [Accepted: 09/14/2017] [Indexed: 01/04/2023] Open
Abstract
Elispot has been used as an important tool for detecting immune cells' products and functions and has facilitated the understanding of host-pathogen interaction. Despite the incredible diversity of possibilities, two main approaches have been developed: the immunopathogenesis and diagnosis/prognosis of infectious diseases as well as cancer research. Much has been described on the topics of allergy, autoimmune diseases, and HIV-Aids, however, Elispot can also be applied to other infectious diseases, mainly leishmaniasis, malaria, some viruses, helminths and mycosis usually classified as tropical diseases. The comprehension of the function, concentration and diversity of the immune response in the infectious disease is pointed out as crucial to the development of infection or disease in humans and animals. In this review we will describe the knowledge already obtained using Elispot as a method for accessing the profile of immune response as well as the recent advances in information about host-pathogen interaction in order to better understand the clinical outcome of a group of tropical and neglected diseases.
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Affiliation(s)
- Josué da Costa Lima-Junior
- Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz/FIOCRUZ, Pavilhão 26-4° andar, sala 406-C, Av. Brasil 4365, Manguinhos, 21045-900 Rio de Janeiro, Brazil.
| | - Fernanda Nazaré Morgado
- Laboratório de Pesquisa em Leishmaniose, Instituto Oswaldo Cruz/FIOCRUZ, Pavilhão 26-5° andar, sala 509, Av. Brasil 4365, Manguinhos, 21045-900 Rio de Janeiro, Brazil.
| | - Fátima Conceição-Silva
- Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz/FIOCRUZ, Pavilhão 26-4° andar, sala 406-C, Av. Brasil 4365, Manguinhos, 21045-900 Rio de Janeiro, Brazil.
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Neubauer JC, Sébastien I, Germann A, Müller SC, Meyerhans A, von Briesen H, Zimmermann H. Towards standardized automated immunomonitoring: an automated ELISpot assay for safe and parallelized functionality analysis of immune cells. Cytotechnology 2016; 69:57-73. [PMID: 27896556 PMCID: PMC5264623 DOI: 10.1007/s10616-016-0037-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/26/2016] [Indexed: 01/06/2023] Open
Abstract
The ELISpot assay is used for the detection of T cell responses in clinical trials and vaccine evaluations. Standardization and reproducibility are necessary to compare the results worldwide, inter- and intra-assay variability being critical factors. To assure operator safety as well as high-quality experiment performance, the ELISpot assay was implemented on an automated liquid handling platform, a Tecan Freedom EVO. After validation of the liquid handling, automated loading of plates with cells and reagents was investigated. With step by step implementation of the manual procedure and liquid dispensing optimization on the robot platform, a fully automated ELISpot assay was accomplished with plates remaining in the system from the plate blocking step to spot development. The mean delta difference amounted to a maximum of 6%, and the mean dispersion was smaller than in the manual assay. Taken together, we achieved with this system not only a lower personnel attendance but also higher throughput and a more precise and parallelized analysis. This platform has the potential to guarantee validated, safe, fast, reproducible and cost-efficient immunological and toxicological assays in the future.
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Affiliation(s)
- J C Neubauer
- Department of Medical Biotechnology, Fraunhofer Institute for Biomedical Engineering, Sulzbach, Germany
| | - I Sébastien
- Department of Medical Biotechnology, Fraunhofer Institute for Biomedical Engineering, Sulzbach, Germany
| | - A Germann
- Department of Medical Biotechnology, Fraunhofer Institute for Biomedical Engineering, Sulzbach, Germany
| | - S C Müller
- Department of Medical Biotechnology, Fraunhofer Institute for Biomedical Engineering, Sulzbach, Germany
| | - A Meyerhans
- Infection Biology Laboratory, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - H von Briesen
- Department of Medical Biotechnology, Fraunhofer Institute for Biomedical Engineering, Sulzbach, Germany
| | - H Zimmermann
- Department of Medical Biotechnology, Fraunhofer Institute for Biomedical Engineering, Sulzbach, Germany. .,Department of Molecular and Cellular Biotechnology, Saarland University, Saarbrücken, Germany.
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7
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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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8
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Flanagan KL, Wilson KL, Plebanski M. Polymorphism in liver-stage malaria vaccine candidate proteins: immune evasion and implications for vaccine design. Expert Rev Vaccines 2015; 15:389-99. [PMID: 26610026 DOI: 10.1586/14760584.2016.1125785] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The pre-erythrocytic stage of infection by malaria parasites represents a key target for vaccines that aim to eradicate malaria. Two important broad immune evasion strategies that can interfere with vaccine efficacy include the induction of dendritic cell (DC) dysfunction and regulatory T cells (Tregs) by blood-stage malaria parasites, leading to inefficient priming of T cells targeting liver-stage infections. The parasite also uses 'surgical strike' strategies, whereby polymorphism in pre-erythrocytic antigens can interfere with host immunity. Specifically, we review how even single amino acid changes in T cell epitopes can lead to loss of binding to major histocompatibility complex (MHC), lack of cross-reactivity, or antagonism and immune interference, where simultaneous or sequential stimulation with related variants of the same T cell epitope can cause T cell anergy or the conversion of effector to immunosuppressive T cell phenotypes.
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Affiliation(s)
- Katie L Flanagan
- a Vaccine and Infectious Diseases Laboratory, Department of Immunology , Monash University , Melbourne , VIC , Australia
| | - Kirsty L Wilson
- a Vaccine and Infectious Diseases Laboratory, Department of Immunology , Monash University , Melbourne , VIC , Australia
| | - Magdalena Plebanski
- a Vaccine and Infectious Diseases Laboratory, Department of Immunology , Monash University , Melbourne , VIC , Australia
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9
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Offeddu V, Thathy V, Marsh K, Matuschewski K. Naturally acquired immune responses against Plasmodium falciparum sporozoites and liver infection. Int J Parasitol 2012; 42:535-48. [DOI: 10.1016/j.ijpara.2012.03.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 03/18/2012] [Accepted: 03/24/2012] [Indexed: 10/28/2022]
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10
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Corradin G, Céspedes N, Verdini A, Kajava AV, Arévalo-Herrera M, Herrera S. Malaria vaccine development using synthetic peptides as a technical platform. Adv Immunol 2012; 114:107-49. [PMID: 22449780 DOI: 10.1016/b978-0-12-396548-6.00005-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The review covers the development of synthetic peptides as vaccine candidates for Plasmodium falciparum- and Plasmodium vivax-induced malaria from its beginning up to date and the concomitant progress of solid phase peptide synthesis (SPPS) that enables the production of long peptides in a routine fashion. The review also stresses the development of other complementary tools and actions in order to achieve the long sought goal of an efficacious malaria vaccine.
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11
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Giraldo NA, Bolaños NI, Cuellar A, Guzman F, Uribe AM, Bedoya A, Olaya N, Cucunubá ZM, Roa N, Rosas F, Velasco V, Puerta CJ, González JM. Increased CD4+/CD8+ double-positive T cells in chronic Chagasic patients. PLoS Negl Trop Dis 2011; 5:e1294. [PMID: 21886854 PMCID: PMC3160296 DOI: 10.1371/journal.pntd.0001294] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 07/19/2011] [Indexed: 01/08/2023] Open
Abstract
Background CD4+/CD8+ double positive (DP) T cells have been described in healthy individuals as well as in patients with autoimmune and chronic infectious diseases. In chronic viral infections, this cell subset has effector memory phenotype and displays antigen specificity. No previous studies of double positive T cells in parasite infections have been carried out. Methodology/Principal Findings Seventeen chronic chagasic patients (7 asymptomatic and 10 symptomatic) and 24 non-infected donors, including 12 healthy and 12 with non-chagasic cardiomyopathy donors were analyzed. Peripheral blood was stained for CD3, CD4, CD8, HLA-DR and CD38, and lymphocytes for intracellular perforin. Antigen specificity was assessed using HLA*A2 tetramers loaded with T. cruzi K1 or influenza virus epitopes. Surface expression of CD107 and intracellular IFN-γ production were determined in K1-specific DP T cells from 11 chagasic donors. Heart tissue from a chronic chagasic patient was stained for both CD8 and CD4 by immunochemistry. Chagasic patients showed higher frequencies of DP T cells (2.1%±0.9) compared with healthy (1.1%±0.5) and non-chagasic cardiomyopathy (1.2%±0.4) donors. DP T cells from Chagasic patients also expressed more HLA-DR, CD38 and perforin and had higher frequencies of T. cruzi K1-specific cells. IFN-γ production in K1-specific cells was higher in asymptomatic patients after polyclonal stimulation, while these cells tended to degranulate more in symptomatic donors. Immunochemistry revealed that double positive T cells infiltrate the cardiac tissue of a chagasic donor. Conclusions Chagasic patients have higher percentages of circulating double positive T cells expressing activation markers, potential effector molecules and greater class I antigenic specificity against T. cruzi. Although K1 tetramer positive DP T cell produced little IFN-γ, they displayed degranulation activity that was increased in symptomatic patients. Moreover, K1-specific DP T cells can migrate to the heart tissue. Chagas disease, produced by the blood parasite Trypanosoma cruzi, is considered a public health problem in Central and South America. Non sterile immunity can be achieved after acute infection. Parasite persistence can induce tissue damage in nearly 20% to 30% of chronically infected individuals. Indeed, chagasic cardiomyopathy is one of the consequences of the chronic infection. Antigen persistence and dysfunctional cellular immune response have been implicated in T. cruzi pathogenesis. Here, a higher frequency of circulating CD4+/CD8+ double positive T cells in chronic chagasic patients is reported as compared with non infected donors, including those with a non-chagasic cardiomyopathy. This cell subset also expressed more activation markers and stored more intracellular perforin. We have previously reported that CD8+ T cells from T. cruzi infected donors recognized the HLA-A*0201 restricted K1-peptide derived from the KMP-11 protein. Here, double positive T cells displayed higher percentages of recognition for the K1 peptide than single CD8+ T cells. These cells produce little IFN-γ, but display degranulation activity that was increased in the symptomatic group. Finally, double positive T cells can be localized in the heart tissue from a chronic chagasic donor.
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Affiliation(s)
- Nicolas A. Giraldo
- Grupo de Ciencias Básicas Médicas, Facultad de Medicina, Universidad de los Andes, Bogotá, Colombia
| | - Natalia I. Bolaños
- Grupo de Ciencias Básicas Médicas, Facultad de Medicina, Universidad de los Andes, Bogotá, Colombia
| | - Adriana Cuellar
- Grupo de Inmunobiología y Biología Celular, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Fanny Guzman
- Núcleo Biotecnología Curauma (NBC), Pontificia Universidad Católica de Valparaíso, Valparaiso, Chile
| | - Ana Maria Uribe
- Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Astrid Bedoya
- Grupo de Infección y Cáncer, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Natalia Olaya
- Instituto de Patología, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Zulma M. Cucunubá
- Grupo de Parasitología, Instituto Nacional de Salud, Bogotá, Colombia
| | - Nubia Roa
- Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
| | | | | | - Concepción J. Puerta
- Laboratorio de Parasitología Molecular, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - John M. González
- Grupo de Ciencias Básicas Médicas, Facultad de Medicina, Universidad de los Andes, Bogotá, Colombia
- * E-mail:
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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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13
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Plasma concentration of malaria parasite-derived macrophage migration inhibitory factor in uncomplicated malaria patients correlates with parasitemia and disease severity. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:1524-32. [PMID: 20702656 DOI: 10.1128/cvi.00149-10] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Host macrophage migration inhibitory factor (MIF) has been implicated in the pathogenesis of malaria infections. Several Plasmodium parasite-derived MIFs were identified to have the potential to regulate host immune response. However, the role of Plasmodium MIFs in the immunopathogenesis of malaria infection and the relationships between these mediators and inflammatory cytokines remained unclear. In this study, we have investigated two Plasmodium MIFs in peripheral blood of uncomplicated malaria patients and analyzed their correlations with several major factors during malaria infection. We found that both Plasmodium falciparum MIF (PfMIF) and Plasmodium vivax MIF (PvMIF) levels in patients were positively correlated with parasitemia, tumor necrosis factor alpha, interleukin-10 (IL-10), and monocyte chemoattractant protein 1 but were not correlated with transforming growth factor β1 and IL-12. Of interest was that the PvMIF level was positively correlated with host body temperature and human MIF (HuMIF) concentrations. Moreover, multiple stepwise regression analysis also showed that parasitemia, IL-10, and HuMIF expression were significant predictors of Plasmodium MIF production. In addition, during antimalarial drug treatment, the decreasing of Plasmodium MIF concentrations was followed by parasitemia in most patients. Our results suggested that the Plasmodium MIF circulating level reflects the level of parasitemia and thus was closely correlated with disease severity in uncomplicated malaria. Therefore, this factor has the potential to be a promising disease predictor and is applicable in clinical diagnosis.
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Audran R, Lurati-Ruiz F, Genton B, Blythman HE, Ofori-Anyinam O, Reymond C, Corradin G, Spertini F. The synthetic Plasmodium falciparum circumsporozoite peptide PfCS102 as a malaria vaccine candidate: a randomized controlled phase I trial. PLoS One 2009; 4:e7304. [PMID: 19798415 PMCID: PMC2749339 DOI: 10.1371/journal.pone.0007304] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 08/25/2009] [Indexed: 11/18/2022] Open
Abstract
Background Fully efficient vaccines against malaria pre-erythrocytic stage are still lacking. The objective of this dose/adjuvant-finding study was to evaluate the safety, reactogenicity and immunogenicity of a vaccine candidate based on a peptide spanning the C-terminal region of Plasmodium falciparum circumsporozoite protein (PfCS102) in malaria naive adults. Methodology and Principal Findings Thirty-six healthy malaria-naive adults were randomly distributed into three dose blocks (10, 30 and 100 µg) and vaccinated with PfCS102 in combination with either Montanide ISA 720 or GSK proprietary Adjuvant System AS02A at days 0, 60, and 180. Primary end-point (safety and reactogenicity) was based on the frequency of adverse events (AE) and of abnormal biological safety tests; secondary-end point (immunogenicity) on P. falciparum specific cell-mediated immunity and antibody response before and after immunization. The two adjuvant formulations were well tolerated and their safety profile was good. Most AEs were local and, when systemic, involved mainly fatigue and headache. Half the volunteers in AS02A groups experienced severe AEs (mainly erythema). After the third injection, 34 of 35 volunteers developed anti-PfCS102 and anti-sporozoite antibodies, and 28 of 35 demonstrated T-cell proliferative responses and IFN-γ production. Five of 22 HLA-A2 and HLA-A3 volunteers displayed PfCS102 specific IFN-γ secreting CD8+ T cell responses. Responses were only marginally boosted after the 3rd vaccination and remained stable for 6 months. For both adjuvants, the dose of 10 µg was less immunogenic in comparison to 30 and 100 µg that induced similar responses. AS02A formulations with 30 µg or 100 µg PfCS102 induced about 10-folds higher antibody and IFN-γ responses than Montanide formulations. Conclusions/Significance PfCS102 peptide was safe and highly immunogenic, allowing the design of more advanced trials to test its potential for protection. Two or three immunizations with a dose of 30 µg formulated with AS02A appeared the most appropriate choice for such studies. Trial Registration Swissmedic.ch 2002 DR 1227
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Affiliation(s)
- Régine Audran
- Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Floriana Lurati-Ruiz
- Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Blaise Genton
- Department of Ambulatory Care and Community Medicine, Policlinique Médicale Universitaire, Lausanne, Switzerland
| | | | | | | | | | - François Spertini
- Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- * E-mail:
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15
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Bongfen SE, Ntsama PM, Offner S, Smith T, Felger I, Tanner M, Alonso P, Nebie I, Romero JF, Silvie O, Torgler R, Corradin G. The N-terminal domain of Plasmodium falciparum circumsporozoite protein represents a target of protective immunity. Vaccine 2008; 27:328-35. [PMID: 18984024 DOI: 10.1016/j.vaccine.2008.09.097] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2008] [Revised: 09/15/2008] [Accepted: 09/24/2008] [Indexed: 12/01/2022]
Abstract
The N-terminal domain of the circumsporozoite protein (CSP) has been largely neglected in the search for a malaria vaccine in spite of being a target of inhibitory antibodies and protective T cell responses in mice. Thus, in order to develop this region as a vaccine candidate to be eventually associated with other candidates and, in particular, with the very advanced C-terminal counterpart, synthetic constructs representing N- and C-terminal regions of Plasmodium falciparum and Plasmodium berghei CSP were administered as single or combined formulations in mice. We show that the antisera generated against the combinations inhibit sporozoite invasion of hepatocytes in vitro better than antisera against single peptides. Furthermore, two different P. falciparum CSP N-terminal constructs (PfCS22-110 and PfCS65-110) were recognized by serum samples from people living in malaria-endemic regions. Importantly, recognition of the short N-terminal peptide (PfCS65-110) by sera from children living in a malaria-endemic region was associated with protection from disease. Taken together, these results underline the potential of using such fragments as malaria vaccine candidates.
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Affiliation(s)
- Silayuv E Bongfen
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066 Epalinges, Switzerland
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Chenet SM, Branch OH, Escalante AA, Lucas CM, Bacon DJ. Genetic diversity of vaccine candidate antigens in Plasmodium falciparum isolates from the Amazon basin of Peru. Malar J 2008; 7:93. [PMID: 18505558 PMCID: PMC2432069 DOI: 10.1186/1475-2875-7-93] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Accepted: 05/27/2008] [Indexed: 11/30/2022] Open
Abstract
Background Several of the intended Plasmodium falciparum vaccine candidate antigens are highly polymorphic and could render a vaccine ineffective if their antigenic sites were not represented in the vaccine. In this study, characterization of genetic variability was performed in major B and T-cell epitopes within vaccine candidate antigens in isolates of P. falciparum from Peru. Methods DNA sequencing analysis was completed on 139 isolates of P. falciparum collected from endemic areas of the Amazon basin in Loreto, Peru from years 1998 to 2006. Genetic diversity was determined in immunological important regions in circumsporozoite protein (CSP), merozoite surface protein-1 (MSP-1), apical membrane antigen-1 (AMA-1), liver stage antigen-1 (LSA-1) and thrombospondin-related anonymous protein (TRAP). Alleles identified by DNA sequencing were aligned with the vaccine strain 3D7 and DNA polymorphism analysis and FST study-year pairwise comparisons were done using the DnaSP software. Multilocus analysis (MLA) was performed and average of expected heterozygosity was calculated for each loci and haplotype over time. Results Three different alleles for CSP, seven for MSP-1 Block 2, one for MSP-1 Block 17, three for AMA-1 and for LSA-1 each and one for TRAP were identified. There were 24 different haplotypes in 125 infections with complete locus typing for each gene. Conclusion Characterization of the genetic diversity in Plasmodium isolates from the Amazon Region of Peru showed that P. falciparum T and B cell epitopes in these antigens have polymorphisms more similar to India than to Africa. These findings are helpful in the formulation of a vaccine considering restricted repertoire populations.
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17
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Jalloh A, van Thien H, Ferreira MU, Ohashi J, Matsuoka H, Kanbe T, Kikuchi A, Kawamoto F. Sequence variation in the T-cell epitopes of the Plasmodium falciparum circumsporozoite protein among field isolates is temporally stable: a 5-year longitudinal study in southern Vietnam. J Clin Microbiol 2006; 44:1229-35. [PMID: 16597843 PMCID: PMC1448650 DOI: 10.1128/jcm.44.4.1229-1235.2006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In an effort to decipher the nature and extent of antigen polymorphisms of malaria parasites in a setting where malaria is hypomesoendemic, we conducted a 5-year longitudinal study (1998 to 2003) by sequencing the Th2R and Th3R epitopes of the circumsporozoite protein (CSP) of 142 Plasmodium falciparum field isolates from Bao Loc, Vietnam. Samples were collected during the high-transmission season, September through December 1998 (n = 43), as well as from July 2000 to August 2001 (n = 34), September 2001 to July 2002 (n = 33), and August 2002 to July 2003 (n = 32). Marked sequence diversity was noted during the high-transmission season in 1998, but no significant variation in allele frequencies was observed over the years (chi(2) = 70.003, degrees of freedom = 57, P = 0.116). The apparent temporal stability in allele frequency observed in this Bao Loc malaria setting may suggest that polymorphism in the Th2R and Th3R epitopes is not maintained by frequency-dependent immune selection. By including 36 isolates from Flores Island, Indonesia, and 19 isolates from Thaton, Myanmar, we investigated geographical patterns of sequence polymorphism for these epitopes in Southeast Asia; among the characterized isolates, a globally distributed variant appears to be predominant in Vietnam (75 of 142 isolates, or 52.8%) as well as in Myanmar (15 of 19 isolates, or 78.9%) and Indonesia (31 of 36 isolates, or 86.1%). Further analyses involving worldwide CSP sequences revealed distinct regional patterns, a finding which, together with the unique mutations observed here, may suggest a possible role for host or local factors in the generation of sequence diversity in the T-cell epitopes of CSP.
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Affiliation(s)
- Amadu Jalloh
- Division of Molecular Mycology and Medicine, Department of Advanced Medical Science, Center for Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-ku, Nagoya, Aichi 466-8550, Japan.
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Diez H, López MC, Del Carmen Thomas M, Guzmán F, Rosas F, Velazco V, González JM, Puerta C. Evaluation of IFN-gamma production by CD8 T lymphocytes in response to the K1 peptide from KMP-11 protein in patients infected with Trypanosoma cruzi. Parasite Immunol 2006; 28:101-5. [PMID: 16441508 DOI: 10.1111/j.1365-3024.2005.00815.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The cellular response mediated by MHC class I restricted CD8+ T cells has been shown to be crucial in the control of Chagas disease. The K1 peptide derived from T. cruzi KMP-11 protein has a high binding affinity to the HLA-A*0201 molecule. Nevertheless, it is not known whether this peptide is processed and displayed as an MHC class I epitope during natural infection by T. cruzi. The aim of this study was to evaluate, by ELISPOT assay, the ability of K1 peptide to activate CD8+ T lymphocytes to produce IFN-gamma. Therefore, CD8+ T lymphocytes from 22 HLA-A*0201+ individuals, 12 chronic chagasic patients and 10 uninfected controls, were analysed. The results revealed that two of the chagasic patients had IFN-gamma-secreting CD8+ T cells that were able to respond to K1 peptide with a relative frequency of 110 and 230 per million CD8+ T cells. In contrast, none of HLA-A*0201+ uninfected controls responded to K1 peptide. Responses to HLA-A*0201 restricted peptide from the influenza matrix protein were found in six chagasic patients and four uninfected controls with an average frequency of 175 and 111 cells per million CD8+ T cells, respectively. Moreover, a flow cytometric assay for degranulation showed that chagasic responders had K1-specific cytotoxic CD8+ T cells. It is shown here for the first time that the K1 peptide is efficiently processed, presented and recognized by CD8+ T lymphocytes during the natural course of Chagas disease.
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Affiliation(s)
- H Diez
- Laboratorio de Parasitología Molecular, Pontificia Universidad Javeriana, Bogotá, Colombia
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Doytchinova IA, Flower DR. Class I T-cell epitope prediction: improvements using a combination of proteasome cleavage, TAP affinity, and MHC binding. Mol Immunol 2006; 43:2037-44. [PMID: 16524630 DOI: 10.1016/j.molimm.2005.12.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2005] [Revised: 11/03/2005] [Accepted: 12/23/2005] [Indexed: 01/03/2023]
Abstract
Cleavage by the proteasome is responsible for generating the C terminus of T-cell epitopes. Modeling the process of proteasome cleavage as part of a multi-step algorithm for T-cell epitope prediction will reduce the number of non-binders and increase the overall accuracy of the predictive algorithm. Quantitative matrix-based models for prediction of the proteasome cleavage sites in a protein were developed using a training set of 489 naturally processed T-cell epitopes (nonamer peptides) associated with HLA-A and HLA-B molecules. The models were validated using an external test set of 227 T-cell epitopes. The performance of the models was good, identifying 76% of the C-termini correctly. The best model of proteasome cleavage was incorporated as the first step in a three-step algorithm for T-cell epitope prediction, where subsequent steps predicted TAP affinity and MHC binding using previously derived models.
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Lyke KE, Burges RB, Cissoko Y, Sangare L, Kone A, Dao M, Diarra I, Fernández-Vina MA, Plowe CV, Doumbo OK, Sztein MB. HLA-A2 supertype-restricted cell-mediated immunity by peripheral blood mononuclear cells derived from Malian children with severe or uncomplicated Plasmodium falciparum malaria and healthy controls. Infect Immun 2005; 73:5799-808. [PMID: 16113298 PMCID: PMC1231120 DOI: 10.1128/iai.73.9.5799-5808.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Understanding HLA-restricted adaptive host immunity to defined epitopes of malarial antigens may be required for the development of successful malaria vaccines. Fourteen epitopes of preerythrocytic malarial antigens known to mediate cytotoxic T-lymphocyte responses against target cells expressing HLA-A2-restricted epitopes were synthesized and pooled based on antigen: thrombospondin-related anonymous protein (TRAP), circumsporozoite protein (CSP), and export protein 1 (Exp-1) peptides. HLA-A2 supertype (*0201, *0202, *0205, *6802) peripheral blood mononuclear cells collected from 774 Malian children, aged 3 months to 14 years, with severe Plasmodium falciparum malaria matched to uncomplicated malaria or healthy controls were stimulated with the HLA-A2-restricted peptide pools. Significant gamma interferon production, determined by enzyme-linked immunospot assay to at least one of the three peptide pools, was observed in 24/58 (41%) of the severe malaria cases, 24/57 (42%) of the uncomplicated malaria cases, and 34/51 (67%) of the healthy controls. Significant lymphoproliferation to these peptides was observed in 12/44 (27%) of the severe malaria cases, 13/55 (24%) of the uncomplicated malaria cases, and 18/50 (36%) of the healthy controls. Responses to individual peptide pools were limited. These studies confirm the presence of adaptive cell-mediated immunity to preerythrocytic malaria antigens in volunteers from Mali and demonstrate that suballeles of the HLA-A2 supertype can effectively present antigenic epitopes. However, whether these immune responses to TRAP, CSP, and Exp-1 malarial proteins play a substantial role in protection remains a matter of controversy.
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Affiliation(s)
- Kirsten E Lyke
- The University of Maryland at Baltimore, Center for Vaccine Development, 685 W. Baltimore St., HSF 480, Baltimore, MD 21201, USA
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Hillier CJ, Ware LA, Barbosa A, Angov E, Lyon JA, Heppner DG, Lanar DE. Process development and analysis of liver-stage antigen 1, a preerythrocyte-stage protein-based vaccine for Plasmodium falciparum. Infect Immun 2005; 73:2109-15. [PMID: 15784552 PMCID: PMC1087442 DOI: 10.1128/iai.73.4.2109-2115.2005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum liver-stage antigen 1 (LSA-1) is expressed solely in infected hepatocytes and is thought to have a role in liver schizogony and merozoite release. Specific humoral, cellular, and cytokine immune responses to LSA-1 are well documented, with epitopes identified that correlate with antibody production, proliferative T-cell responses, or cytokine induction. With the goal of developing a vaccine against this preerythrocyte-stage protein, we undertook the good manufacturing practices (GMP) manufacture of a recombinant LSA-1 construct, LSA-NRC, incorporating the N- and C-terminal regions of the protein and two of the centrally placed 17-amino-acid repeats. To improve the protein yield, a method of codon harmonization was employed to reengineer the gene sequence for expression in Escherichia coli. A 300-liter GMP fermentation produced 8 kg of bacterial cell paste, and a three-step column chromatographic method yielded 8 mg of purified antigen per g of paste. The final bulk protein was >98% pure, demonstrated long-term stability, and contained <0.005 endotoxin units per 50 microg of protein. To accomplish the initial stages of evaluation of this protein as a human-use vaccine against malaria, we immunized rabbits and mice with LSA-NRC in Montanide ISA 720. New Zealand White rabbits and A/J (H-2K) mice produced high-titer antibodies that recognized liver-stage parasites in infected cultured human hepatocytes. Gamma interferon-producing cells, which have been associated with LSA-1-mediated protection, were detected in splenocytes harvested from immunized mice. Finally, sera taken from people living in a region where malaria is holoendemic recognized LSA-NRC by Western blotting.
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Affiliation(s)
- Collette J Hillier
- Department of Immunology, Walter Reed Army Institute of Research, 503 Robert Grant Ave., Silver Spring, MD 20910-7500, USA
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Meraldi V, Romero JF, Kensil C, Corradin G. A strong CD8+ T cell response is elicited using the synthetic polypeptide from the C-terminus of the circumsporozoite protein of Plasmodium berghei together with the adjuvant QS-21: quantitative and phenotypic comparison with the vaccine model of irradiated sporozoites. Vaccine 2005; 23:2801-12. [PMID: 15780728 DOI: 10.1016/j.vaccine.2004.10.044] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2004] [Revised: 09/06/2004] [Accepted: 10/25/2004] [Indexed: 10/26/2022]
Abstract
Stable protective immunity can be achieved against malaria by the injection of radiation-attenuated sporozoites (gamma-spz) and is mediated by IFN-gamma producing CD8+ T cells targeting the pre-erythrocytic stages. An efficient malaria vaccine should mimic this immunity. We compared the immune response specific for the circumsporozoite protein (CSP) of Plasmodium berghei (P. berghei), an important target of this protective response, elicited in mice immunized with the long synthetic polypeptide (LSP) PbCS 242-310, representing the C-terminus of the CSP of P. berghei, with the adjuvant QS-21 or injected with gamma-spz. The ex vivo evaluation of the CD8+ T cell response by IFN-gamma ELISPOT assay revealed that the injection of LSP with QS-21 induced, compared to gamma-spz, a similar frequency of peptide-specific lymphocytes in the spleen but a eight-fold increase in the draining lymph-nodes. A very high frequency of CD8+ T cells, specific for the sequence PbCS 245-253, a H-2Kd-restricted CTL epitope, was obtained in the liver and spleen of mice immunized with the two regimens. Even though the frequency of H-2Kd PbCS 245-253 multimer+, CD8+ T cells was higher in gamma-spz immunized mice, the frequency of IFN-gamma producing CD8+ T cells was comparable. The phenotype of the CD8+ T cell responses was characterized with the help H-2Kd PbCS 245-253 multimer and most of the CSP-specific CD8+ T cells represented an intermediate subset between effector and central memory with CD44(high), CD45RB(high), CD62L(low) and CD122(high). The number of memory CD8+ T cells decreased after the last LSP immunization but could be boosted to higher level with live spz. The unique combination of LSP PbCS 242-310 and the adjuvant QS-21 induced an immune response that was comparable in terms of quality to the one generated with gamma-spz. This confirmed the potential of LSP as malaria vaccine candidates as well as for the study of the repertoire of targets of protective immunity in the gamma-spz vaccine model.
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Affiliation(s)
- Valentin Meraldi
- Department of Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland
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23
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Corradin G, Spertini F, Verdini A. Medicinal application of long synthetic peptide technology. Expert Opin Biol Ther 2005; 4:1629-39. [PMID: 15461574 DOI: 10.1517/14712598.4.10.1629] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This review covers the latest developments of long synthetic peptide technology for the rapid identification and development of malaria vaccine candidates and immunological modulators. A brief description of the two most common solid-phase synthetic procedures, together with the latest advances in optimisation of peptide chain assembly and analytical instrumentation, is given, with special attention to non-specialists. Several examples of vaccine candidates developed in the authors' or their collaborators' laboratories are also provided.
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24
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John CC, Moormann AM, Sumba PO, Ofulla AV, Pregibon DC, Kazura JW. Gamma interferon responses to Plasmodium falciparum liver-stage antigen 1 and thrombospondin-related adhesive protein and their relationship to age, transmission intensity, and protection against malaria. Infect Immun 2004; 72:5135-42. [PMID: 15322007 PMCID: PMC517451 DOI: 10.1128/iai.72.9.5135-5142.2004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2004] [Revised: 05/22/2004] [Accepted: 06/01/2004] [Indexed: 11/20/2022] Open
Abstract
Gamma interferon (IFN-gamma) responses to the Plasmodium falciparum antigens liver-stage antigen 1 (LSA-1) and thrombospondin-related adhesive protein (TRAP) are thought to be important in protection against malaria. Optimal methods of testing and the effects of age and transmission intensity on these responses are unknown. IFN-gamma responses to LSA-1 and TRAP peptides were assessed by the enzyme-linked immunospot assay (ELISPOT) and enzyme-linked immunosorbent assay (ELISA) in children and adults from areas of stable and unstable malaria transmission in Kenya. Adults in the areas of stable and unstable transmission had similar frequencies and levels of IFN-gamma responses to LSA-1 and TRAP as determined by ELISPOT and ELISA. In contrast, IFN-gamma responses to the LSA-1 T3 peptide (assessed by ELISPOT) and to any LSA-1 peptide (assessed by ELISA) were less frequent in children in the area of unstable transmission than in children in the area of stable transmission. IFN-gamma responses to LSA-1 were more frequently detected by ELISA than by ELISPOT in the stable-transmission area. IFN-gamma responses detected by ELISA and ELISPOT did not correlate with each other. In children in the stable-transmission area, IFN-gamma responses to LSA-1 peptides assessed by ELISA, but not by ELISPOT, were associated with protection against clinical malaria and anemia. IFN-gamma responses to LSA-1 appear to require repeated P. falciparum exposure and/or increased age and, as measured by ELISA, are associated with protection against clinical malaria and anemia.
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Affiliation(s)
- Chandy C John
- Center for Global Health and Diseases, Case Western Researve University, Cleveland, OH, USA.
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25
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Rodrigues MM, Boscardin SB, Vasconcelos JR, Hiyane MI, Salay G, Soares IS. Importance of CD8 T cell-mediated immune response during intracellular parasitic infections and its implications for the development of effective vaccines. AN ACAD BRAS CIENC 2003; 75:443-68. [PMID: 14605680 DOI: 10.1590/s0001-37652003000400005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Obligatory intracellular parasites such as Plasmodium sp, Trypanosoma cruzi, Toxoplasma gondii and Leishmania sp are responsible for the infection of hundreds of millions of individuals every year. These parasites can deliver antigens to the host cell cytoplasm that are presented through MHC class I molecules to protective CD8 T cells. The in vivo priming conditions of specific CD8 T cells during natural infection are largely unknown and remain as an area that has been poorly explored. The antiparasitic mechanisms mediated by CD8 T cells include both interferon-gamma-dependent and -independent pathways. The fact that CD8 T cells are potent inhibitors of parasitic development prompted many investigators to explore whether induction of these T cells can be a feasible strategy for the development of effective subunit vaccines against these parasitic diseases. Studies performed on experimental models supported the hypothesis that CD8 T cells induced by recombinant viral vectors or DNA vaccines could serve as the basis for human vaccination. Regimens of immunization consisting of two different vectors (heterologous prime-boost) are much more efficient in terms of expansion of protective CD8 T lymphocytes than immunization with a single vector. The results obtained using experimental models have led to clinical vaccination trials that are currently underway.
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Affiliation(s)
- Mauricio M Rodrigues
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, 04023-062 São Paulo, SP, Brasil.
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26
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Hetttihewa LM. Immunization of retrovirus-transfected dendritic cells induces specific cytotoxic T lymphocytes for two distinct malarial peptides presented by Kd molecule. Int Immunopharmacol 2003; 3:1401-11. [PMID: 12946436 DOI: 10.1016/s1567-5769(03)00137-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Plasmodium yoelli sporozoite surface protein 2 (pySSP2) is considered as an important antigen for protection studies in malaria vaccine development. For the liver stage protection, anti-pySSP2 cytotoxic T lymphocyte (CTL) activity in BALB/c mice was investigated by immunization of genetically engineered bone marrow-derived dendritic cells (DCs) expressing pySSP2 peptides. Retrovirus-transfected bone marrow cells cultured with GMCSF and IL-4 for 7 days demonstrated 70-80% of DCs with high CD11c, CD80, CD86, and MHC class I (I-Kd) expression. Dividing bone marrow cells were infected with retrovirus expressing SSP2 on fifth, sixth, and seventh days of culture by prolonged centrifugation for 1 h at 32 degrees C. Transfection efficacy of DCs was assessed using retrovirus-shuttled green fluorescence vector (pMSCV-EGFP neo). A total of 64% of CD11c positive transfected DCs showed green fluorescence. The degree of SSP2 expression in transfected DCs was assessed by immunoprecipitation with SSP2 antibody. Both SSP2 and EGFP transfected DCs had prolonged expression of the engineered gene until day 6 since the transfection. Antigen presentation to nai;ve CTLs was assessed by immunization of retrovirus-infected DCs into BALB/c mice. Kd restricted, antigen-specific two new MHC class I (I-Kd) binding motifs were identified (A and C) in pySSP2 protein. Both A and C induced peptide-specific, IFN-gamma-secreting cytolytic CTLs upon antigen recognition on target cells. Taken together, these data indicate that genetically modified DCs by prolonged centrifugation is effective in enhanced antigen presentation. Immunization of DCs encoding SSP2 gene resulted in identification of two K(d) restricted CTL epitopes and induction of IFN-gamma-secreting cytolytic CD8+ T cells.
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Meraldi V, Audran R, Romero JF, Brossard V, Bauer J, López JA, Corradin G. OM-174, a new adjuvant with a potential for human use, induces a protective response when administered with the synthetic C-terminal fragment 242-310 from the circumsporozoite protein of Plasmodium berghei. Vaccine 2003; 21:2485-91. [PMID: 12744882 DOI: 10.1016/s0264-410x(03)00093-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
The goal of this project was the evaluation of a novel immunomodulatory adjuvant for human use, OM-174, which is a soluble adjuvant derived from Escherichia coli lipid A. For this study, we used a synthetic peptide, known for its safety and reproducibility and the murine model of BALB/c mice. The long peptide (PbCS 242-310) used corresponds to the C-terminal region of the circumsporozoite protein (CSP) that is the major protein on the surface of Plasmodium sporozoites. Subcutaneous injections of PbCS 242-310 in combination with soluble adjuvant OM-174 induced long lasting peptide-specific antibody titres comparable to those obtained by immunization with incomplete Freund's adjuvant (IFA). The ex vivo evaluation of the CD8(+) T cell response by IFN-gamma ELISPOT assay revealed that the injection of polypeptide with OM-174 adjuvant induced, compared to IFA, a similar and an eight-fold increased frequency of peptide-specific lymphocytes in the draining lymph-nodes and in the spleen, respectively. The CD8(+) T-cells are specific for the sequence PbCS 245-253, a well-known H-2K(d)-restricted CTL epitope, and are cytotoxic as shown in a chromium release assay. Immunization of BALB/c mice with this polypeptide in combination with adjuvant OM-174 conferred a protection after challenge with live Plasmodium berghei sporozoites.The strong antibody and CTL responses observed to a synthetic peptide in mice, the safety profile of the adjuvant and its extensive physico-chemical characterization suggest that OM-174 has a potential use in vaccine formulations for humans.
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Affiliation(s)
- Valentin Meraldi
- Institute of Biochemistry, University of Lausanne, Epalinges, Switzerland
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28
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López JA, Bioley G, Turtle CJ, Pinzón-Charry A, Ho CSK, Vuckovic S, Crosbie G, Gilleece M, Jackson DC, Munster D, Hart DNJ. Single step enrichment of blood dendritic cells by positive immunoselection. J Immunol Methods 2003; 274:47-61. [PMID: 12609532 DOI: 10.1016/s0022-1759(02)00429-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Dendritic cells (DC) for cancer immunotherapy protocols are generated most commonly by in vitro differentiation of monocytes with exogenous cytokines (Mo-DC). However, Mo-DC differ in their molecular phenotype and function from blood DC (BDC). Clinical isolation of BDC has been limited to the use of density gradients, which result in low yields of variable purity. We have developed a DC enrichment platform, which uses the CMRF-44 (IgM) or CMRF-56 (IgG) monoclonal antibodies (mAb) to select BDC that express these antigens after a short overnight incubation. After culture of peripheral blood mononuclear cells (PBMC) in autologous/AB serum, biotinylated CMRF-44 was used to select DC in a single step immuno-magnetic bead procedure; this produced populations containing up to 99% CMRF-44(+) cells, including up to 67% CMRF-44(+) CD14(-) CD19(-) DC, from an initial starting population of approximately 0.5%. We observed consistent differences in the purities obtained from individual donors with a mean of 54% CMRF-44(+) cells (range 19-99%). Similar results were obtained using biotinylated CMRF-56 mAb, an antibody identifying a comparable population in cultured PBMC. We recovered an average of 54% and 66% of the available BDC in separations performed with the CMRF-44 and CMRF-56 mAb, respectively. The reproducibility of the procedure and the ability to perform it in a closed sterile system makes it suitable for clinical use. Larger scale preparations starting from apheresis derived PBMC will produce sufficient BDC for immunotherapy protocols. The purified BDC elicited strong allogeneic mixed leukocyte reactions and HLA classes II- and I-restricted antigen-specific primary immune responses.
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Affiliation(s)
- J Alejandro López
- Mater Medical Research Institute, Aubigny Place, 4101, South Brisbane, Australia
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29
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Salerno-Goncalves R, Pasetti MF, Sztein MB. Characterization of CD8(+) effector T cell responses in volunteers immunized with Salmonella enterica serovar Typhi strain Ty21a typhoid vaccine. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:2196-203. [PMID: 12165550 DOI: 10.4049/jimmunol.169.4.2196] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Salmonella enterica serovar Typhi (S. typhi) strain Ty21a remains the only licensed attenuated typhoid vaccine. Despite years of research, the identity of the protective immunological mechanisms elicited by immunization with the Ty21a typhoid vaccine remains elusive. The present study was designed to characterize effector T cell responses in volunteers immunized with S. typhi strain Ty21a typhoid vaccine. We determined whether immunization with Ty21a induced specific CTL able to lyse S. typhi-infected cells and secrete IFN-gamma, a key effector molecule against intracellular pathogens. We measured the functional activity of these CTL by a (51)Cr-release assay using 8-day restimulated PBMC from Ty21a vaccinees as effector cells and S. Typhi-infected autologous PHA-activated PBMC as target cells. Most vaccinees exhibited consistently increased CD8-mediated lysis of targets by postimmunization PBMC when compared with preimmunization levels. We also developed an IFN-gamma ELISPOT assay to quantify the frequency of IFN-gamma spot-forming cells (SFC) in PBMC from Ty21a vaccinees using an ex vivo system. Significant increases in the frequency of IFN-gamma SFC following immunization (mean +/- SD, 393 +/- 172; range 185-548 SFC/10(6) PBMC; p = 0.010), as compared with preimmunization levels, were observed. IFN-gamma was secreted predominantly by CD8(+) T cells. A strong correlation was recorded between the cytolytic activity of CTL lines and the frequency of IFN-gamma SFC (r(2) = 0.910, p < 0.001). In conclusion, this work constitutes the first evidence that immunization of volunteers with Ty21a elicits specific CD8(+) CTL and provides an estimate of the frequency of CD8(+) IFN-gamma-secreting cells induced by vaccination.
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Affiliation(s)
- Rosângela Salerno-Goncalves
- Center for Vaccine Development, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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30
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Arévalo-Herrera M, Valencia AZ, Vergara J, Bonelo A, Fleischhauer K, González JM, Restrepo JC, López JA, Valmori D, Corradin G, Herrera S. Identification of HLA-A2 restricted CD8(+) T-lymphocyte responses to Plasmodium vivax circumsporozoite protein in individuals naturally exposed to malaria. Parasite Immunol 2002; 24:161-9. [PMID: 12078650 DOI: 10.1046/j.1365-3024.2002.00449.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Specific CD8(-) T-lymphocyte (CTL) activity against Plasmodium pre-erythrocytic stages (P-ES) derived antigens is considered one of the most important mechanisms for malaria protection. Plasmodium vivax is the second most prevalent human malaria parasite species distributed worldwide. Although several CTL epitopes have been identified in Plasmodium falciparum P-ES derived antigens, none has been described for P. vivax to date. In this study, we analysed HLA-A*0201 specific CD8(-) T-lymphocyte responses to the P. vivax circumsporozoite (CS) protein in both malaria exposed and non-exposed populations from the Colombian Pacific Coast. First, we analysed the prevalence of HLA-A2 allele in the study populations and found that approximately 38 of the individuals expressed this molecule and that 50 of them were HLA-A*0201. We then selected, on the P. vivax CS, five peptide sequences containing the HLA-A*0201 binding motifs and used the corresponding synthetic peptides to evaluate the CD8(-) T-lymphocyte interferon (IFN)-gamma response. Peripheral blood mononuclear cells from the HLA-A*0201 donors were in vitro stimulated with these peptides and IFN-gamma production was determined by an ELISPOT assay. Specific CD8(-) T-lymphocyte responses were detected for three peptides located in the C-terminal region of the protein. Specific responses to these peptides were also detected in several individuals expressing different HLA-A*02 subtypes. The potential of these peptides to induce specific cytolysis and that of long synthetic peptides comprising these epitopes as P. vivax malaria vaccine subunits are being studied.
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Abstract
Plasmodium vivax represents the most widespread malaria parasite worldwide. Although it does not result in as high a mortality rate as P. falciparum, it inflicts debilitating morbidity and consequent economic impact in endemic communities. In addition, the relapsing behavior of this malaria parasite and the recent resistance to anti-malarials contribute to making its control more difficult. Although the biology of P. vivax is different from that of P. falciparum and the human immune response to this parasite species has been rather poorly studied, significant progress is being made to develop a P. vivax-specific vaccine based on the information and experience gained in the search for a P. falciparum vaccine. We have devoted great effort to antigenically characterize the P. vivax CS protein and to test its immunogenicity using the Aotus monkey model. Together with other groups we are also assessing the immunogenicity and protective efficacy of the asexual blood stage vaccine candidates MSP-1 and DBP in the monkey model, as well as the immunogenicity of Pvs25 and Pvs28 ookinete surface proteins. The transmission-blocking efficacy of the responses induced by these latter antigens is being assessed using Anopheles albimanus mosquitoes. The current status of these vaccine candidates and other antigens currently being studied is described.
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López J, Weilenman C, Audran R, Roggero M, Bonelo A, Tiercy JM, Spertini F, Corradin G. A synthetic malaria vaccine elicits a potent CD8+ and CD4+ T lymphocyte immune response in humans. Implications for vaccination strategies. Eur J Immunol 2001. [DOI: 10.1002/1521-4141(200107)31:7<1989::aid-immu1989>3.0.co;2-m] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Gómez-Duarte OG, Pasetti MF, Santiago A, Sztein MB, Hoffman SL, Levine MM. Expression, extracellular secretion, and immunogenicity of the Plasmodium falciparum sporozoite surface protein 2 in Salmonella vaccine strains. Infect Immun 2001; 69:1192-8. [PMID: 11160021 PMCID: PMC98005 DOI: 10.1128/iai.69.2.1192-1198.2001] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Deleting transmembrane alpha-helix motifs from Plasmodium falciparum sporozoite surface protein (SSP-2) allowed its secretion from Salmonella enterica serovar Typhimurium SL3261 and S. enterica serovar Typhi CVD 908-htrA by the Hly type I secretion system. In mice immunized intranasally, serovar Typhimurium constructs secreting SSP-2 stimulated greater gamma interferon splenocyte responses than did nonsecreting constructs (P = 0.04).
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Affiliation(s)
- O G Gómez-Duarte
- Center for Vaccine Development, Department of Medicine, School of Medicine, University of Maryland, Baltimore, Maryland 21201, USA
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