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Identification and Characterization of the Rhoptry Neck Protein 2 in Babesia divergens and B. microti. Infect Immun 2016; 84:1574-1584. [PMID: 26953328 DOI: 10.1128/iai.00107-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/01/2016] [Indexed: 01/07/2023] Open
Abstract
Apicomplexan parasites include those of the genera Plasmodium, Cryptosporidium, and Toxoplasma and those of the relatively understudied zoonotic genus Babesia In humans, babesiosis, particularly transfusion-transmitted babesiosis, has been emerging as a major threat to public health. Like malaria, the disease pathology is a consequence of the parasitemia which develops through cyclical replication of Babesia parasites in host erythrocytes. However, there are no exoerythrocytic stages in Babesia, so targeting of the blood stage and associated proteins to directly prevent parasite invasion is the most desirable option for effective disease control. Especially promising among such molecules are the rhoptry neck proteins (RONs), whose homologs have been identified in many apicomplexan parasites. RONs are involved in the formation of the moving junction, along with AMA1, but no RON has been identified and characterized in any Babesia spp. Here we identify the RON2 proteins of Babesia divergens (BdRON2) and B. microti (BmRON2) and show that they are localized apically and that anti-BdRON2 antibodies are significant inhibitors of parasite invasion in vitro Neither protein is immunodominant, as both proteins react only marginally with sera from infected animals. Further characterization of the direct role of both BdRON2 and BmRON2 in parasite invasion is required, but knowledge of the level of conformity of RON2 proteins within the apicomplexan phylum, particularly that of the AMA1-RON2 complex at the moving junction, along with the availability of an animal model for B. microti studies, provides a key to target this complex with a goal of preventing the erythrocytic invasion of these parasites and to further our understanding of the role of these conserved ligands in invasion.
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2
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Abstract
There have been significant decreases in malaria mortality and morbidity in the last 10-15 years, and the most advanced pre-erythrocytic malaria vaccine, RTS,S, received a positive opinion from European regulators in July 2015. However, no blood-stage vaccine has reached a phase III trial. The first part of this review summarizes the pros and cons of various assays and models that have been and will be used to predict the efficacy of blood-stage vaccines. In the second part, blood-stage vaccine candidates that showed some efficacy in human clinical trials or controlled human malaria infection models are discussed. Then, candidates under clinical investigation are described in the third part, and other novel candidates and strategies are reviewed in the last part.
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Affiliation(s)
- Kazutoyo Miura
- a Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases , National Institutes of Health , Rockville , MD , USA
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3
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Douglas AD, Baldeviano GC, Lucas CM, Lugo-Roman LA, Crosnier C, Bartholdson SJ, Diouf A, Miura K, Lambert LE, Ventocilla JA, Leiva KP, Milne KH, Illingworth JJ, Spencer AJ, Hjerrild KA, Alanine DGW, Turner AV, Moorhead JT, Edgel KA, Wu Y, Long CA, Wright GJ, Lescano AG, Draper SJ. A PfRH5-based vaccine is efficacious against heterologous strain blood-stage Plasmodium falciparum infection in aotus monkeys. Cell Host Microbe 2015; 17:130-9. [PMID: 25590760 PMCID: PMC4297294 DOI: 10.1016/j.chom.2014.11.017] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 09/11/2014] [Accepted: 11/13/2014] [Indexed: 12/22/2022]
Abstract
Antigenic diversity has posed a critical barrier to vaccine development against the pathogenic blood-stage infection of the human malaria parasite Plasmodium falciparum. To date, only strain-specific protection has been reported by trials of such vaccines in nonhuman primates. We recently showed that P. falciparum reticulocyte binding protein homolog 5 (PfRH5), a merozoite adhesin required for erythrocyte invasion, is highly susceptible to vaccine-inducible strain-transcending parasite-neutralizing antibody. In vivo efficacy of PfRH5-based vaccines has not previously been evaluated. Here, we demonstrate that PfRH5-based vaccines can protect Aotus monkeys against a virulent vaccine-heterologous P. falciparum challenge and show that such protection can be achieved by a human-compatible vaccine formulation. Protection was associated with anti-PfRH5 antibody concentration and in vitro parasite-neutralizing activity, supporting the use of this in vitro assay to predict the in vivo efficacy of future vaccine candidates. These data suggest that PfRH5-based vaccines have potential to achieve strain-transcending efficacy in humans. Vaccines based on the P. falciparum merozoite antigen PfRH5 were tested in Aotus monkeys PfRH5-based vaccines afforded protection against heterologous strains of P. falciparum Protection correlated with anti-PfRH5 IgG concentration and in vivo neutralization
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Affiliation(s)
| | | | - Carmen M Lucas
- US Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | | | | | | | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Lynn E Lambert
- Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, Rockville, MD 20852, USA
| | | | - Karina P Leiva
- US Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | | | | | | | | | | | | | | | | | - Yimin Wu
- Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, Rockville, MD 20852, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | | | | | - Simon J Draper
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
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4
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Llewellyn D, de Cassan SC, Williams AR, Douglas AD, Forbes EK, Adame-Gallegos JR, Shi J, Pleass RJ, Draper SJ. Assessment of antibody-dependent respiratory burst activity from mouse neutrophils on Plasmodium yoelii malaria challenge outcome. J Leukoc Biol 2014; 95:369-82. [PMID: 24163420 PMCID: PMC3896657 DOI: 10.1189/jlb.0513274] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 09/23/2013] [Accepted: 10/01/2013] [Indexed: 01/12/2023] Open
Abstract
New tools are required to expedite the development of an effective vaccine against the blood-stage infection with the human malaria parasite Plasmodium falciparum. This work describes the assessment of the ADRB assay in a mouse model, characterizing the functional interaction between antimalarial serum antibodies and FcRs upon neutrophils. We describe a reproducible, antigen-specific assay, dependent on functional FcR signaling, and show that ADRB activity is induced equally by IgG1 and IgG2a isotypes and is modulated by blocking FcR function. However, following immunization of mice with the blood-stage vaccine candidate antigen MSP142, no measurable ADRB activity was induced against PEMS and neither was vaccine efficacy modulated against Plasmodium yoelii blood-stage challenge in γ(-/-) mice compared with WT mice. In contrast, following a primary, nonlethal P. yoelii parasite challenge, serum from vaccinated mice and nonimmunized controls showed anti-PEMS ADRB activity. Upon secondary challenge, nonimmunized γ(-/-) mice showed a reduced ability to control blood-stage parasitemia compared with immunized γ(-/-) mice; however, WT mice, depleted of their neutrophils, did not lose their ability to control infection. Thus, whereas neutrophil-induced ADRB against PEMS does not appear to play a role in protection against P. yoelii rodent malaria, induction of ADRB activity after challenge suggests that antigen targets of anti-PEMS ADRB activity remain to be established, as well as further supporting the observation that ADRB activity to P. falciparum arises following repeated natural exposure.
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Affiliation(s)
- David Llewellyn
- 1.University of Oxford, Old Road Campus Research Building, Oxford, OX3 7DQ, UK.
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5
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Cavanagh DR, Kocken CHM, White JH, Cowan GJM, Samuel K, Dubbeld MA, der Wel AVV, Thomas AW, McBride JS, Arnot DE. Antibody responses to a novel Plasmodium falciparum merozoite surface protein vaccine correlate with protection against experimental malaria infection in Aotus monkeys. PLoS One 2014; 9:e83704. [PMID: 24421900 PMCID: PMC3885447 DOI: 10.1371/journal.pone.0083704] [Citation(s) in RCA: 8] [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: 09/05/2013] [Accepted: 11/06/2013] [Indexed: 11/29/2022] Open
Abstract
The Block 2 region of the merozoite surface protein-1 (MSP-1) of Plasmodium falciparum has been identified as a target of protective immunity by a combination of seroepidemiology and parasite population genetics. Immunogenicity studies in small animals and Aotus monkeys were used to determine the efficacy of recombinant antigens derived from this region of MSP-1 as a potential vaccine antigen. Aotus lemurinus griseimembra monkeys were immunized three times with a recombinant antigen derived from the Block 2 region of MSP-1 of the monkey-adapted challenge strain, FVO of Plasmodium falciparum, using an adjuvant suitable for use in humans. Immunofluorescent antibody assays (IFA) against erythrocytes infected with P. falciparum using sera from the immunized monkeys showed that the MSP-1 Block 2 antigen induced significant antibody responses to whole malaria parasites. MSP-1 Block 2 antigen-specific enzyme-linked immunosorbent assays (ELISA) showed no significant differences in antibody titers between immunized animals. Immunized animals were challenged with the virulent P. falciparum FVO isolate and monitored for 21 days. Two out of four immunized animals were able to control their parasitaemia during the follow-up period, whereas two out of two controls developed fulminating parasitemia. Parasite-specific serum antibody titers measured by IFA were four-fold higher in protected animals than in unprotected animals. In addition, peptide-based epitope mapping of serum antibodies from immunized Aotus showed distinct differences in epitope specificities between protected and unprotected animals.
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Affiliation(s)
- David R. Cavanagh
- Institute of Immunology and Infection Research, Center for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Clemens H. M. Kocken
- Biomedical Primate Research Center, Department of Parasitology, Rijswijk, The Netherlands
| | - John H. White
- Institute of Immunology and Infection Research, Center for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Graeme J. M. Cowan
- Institute of Immunology and Infection Research, Center for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Kay Samuel
- Scottish National Blood Transfusion Service, Cell Therapy Group, University of Edinburgh, Edinburgh, United Kingdom
| | - Martin A. Dubbeld
- Biomedical Primate Research Center, Department of Parasitology, Rijswijk, The Netherlands
| | | | - Alan W. Thomas
- Biomedical Primate Research Center, Department of Parasitology, Rijswijk, The Netherlands
| | - Jana S. McBride
- Institute of Immunology and Infection Research, Center for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - David E. Arnot
- Institute of Immunology and Infection Research, Center for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
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6
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Sheehy SH, Douglas AD, Draper SJ. Challenges of assessing the clinical efficacy of asexual blood-stage Plasmodium falciparum malaria vaccines. Hum Vaccin Immunother 2013; 9:1831-40. [PMID: 23778312 PMCID: PMC3906345 DOI: 10.4161/hv.25383] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In the absence of any highly effective vaccine candidate against Plasmodium falciparum malaria, it remains imperative for the field to pursue all avenues that may lead to the successful development of such a formulation. The development of a subunit vaccine targeting the asexual blood-stage of Plasmodium falciparum malaria infection has proven particularly challenging with only limited success to date in clinical trials. However, only a fraction of potential blood-stage vaccine antigens have been evaluated as targets, and a number of new promising candidate antigen formulations and delivery platforms are approaching clinical development. It is therefore essential that reliable and sensitive methods of detecting, or ruling out, even modest efficacy of blood-stage vaccines in small clinical trials be established. In this article we evaluate the challenges facing blood-stage vaccine developers, assess the appropriateness and limitations of various in vivo approaches for efficacy assessment and suggest future directions for the field.
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7
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Valencia SH, Rodríguez DC, Acero DL, Ocampo V, Arévalo-Herrera M. Platform for Plasmodium vivax vaccine discovery and development. Mem Inst Oswaldo Cruz 2011; 106 Suppl 1:179-92. [PMID: 21881773 PMCID: PMC4832982 DOI: 10.1590/s0074-02762011000900023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 06/15/2011] [Indexed: 01/17/2023] Open
Abstract
Plasmodium vivax is the most prevalent malaria parasite on the American continent. It generates a global burden of 80-100 million cases annually and represents a tremendous public health problem, particularly in the American and Asian continents. A malaria vaccine would be considered the most cost-effective measure against this vector-borne disease and it would contribute to a reduction in malaria cases and to eventual eradication. Although significant progress has been achieved in the search for Plasmodium falciparum antigens that could be used in a vaccine, limited progress has been made in the search for P. vivax components that might be eligible for vaccine development. This is primarily due to the lack of in vitro cultures to serve as an antigen source and to inadequate funding. While the most advanced P. falciparum vaccine candidate is currently being tested in Phase III trials in Africa, the most advanced P. vivax candidates have only advanced to Phase I trials. Herein, we describe the overall strategy and progress in P. vivax vaccine research, from antigen discovery to preclinical and clinical development and we discuss the regional potential of Latin America to develop a comprehensive platform for vaccine development.
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8
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Lozano JM, Lesmes LP, Carreño LF, Gallego GM, Patarroyo ME. Development of designed site-directed pseudopeptide-peptido-mimetic immunogens as novel minimal subunit-vaccine candidates for malaria. Molecules 2010; 15:8856-89. [PMID: 21135800 PMCID: PMC6259129 DOI: 10.3390/molecules15128856] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Accepted: 10/28/2010] [Indexed: 11/16/2022] Open
Abstract
Synthetic vaccines constitute the most promising tools for controlling and preventing infectious diseases. When synthetic immunogens are designed from the pathogen native sequences, these are normally poorly immunogenic and do not induce protection, as demonstrated in our research. After attempting many synthetic strategies for improving the immunogenicity properties of these sequences, the approach consisting of identifying high binding motifs present in those, and then performing specific changes on amino-acids belonging to such motifs, has proven to be a workable strategy. In addition, other strategies consisting of chemically introducing non-natural constraints to the backbone topology of the molecule and modifying the α-carbon asymmetry are becoming valuable tools to be considered in this pursuit. Non-natural structural constraints to the peptide backbone can be achieved by introducing peptide bond isosters such as reduced amides, partially retro or retro-inverso modifications or even including urea motifs. The second can be obtained by strategically replacing L-amino-acids with their enantiomeric forms for obtaining both structurally site-directed designed immunogens as potential vaccine candidates and their Ig structural molecular images, both having immuno-therapeutic effects for preventing and controlling malaria.
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MESH Headings
- Animals
- Haplorhini
- Humans
- Malaria Vaccines/chemical synthesis
- Malaria Vaccines/chemistry
- Malaria Vaccines/immunology
- Malaria Vaccines/pharmacology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/prevention & control
- Mice
- Mice, Inbred BALB C
- Peptidomimetics/chemical synthesis
- Peptidomimetics/chemistry
- Peptidomimetics/immunology
- Peptidomimetics/pharmacology
- Vaccines, Subunit/chemical synthesis
- Vaccines, Subunit/chemistry
- Vaccines, Subunit/immunology
- Vaccines, Subunit/pharmacology
- Vaccines, Synthetic/chemistry
- Vaccines, Synthetic/immunology
- Vaccines, Synthetic/pharmacology
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Affiliation(s)
- José Manuel Lozano
- Fundación Instituto de Inmunología de Colombia (FIDIC), Universidad del Rosario and Universidad Nacional de Colombia, Bogotá DC, Colombia.
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9
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Jiang G, Charoenvit Y, Moreno A, Baraceros MF, Banania G, Richie N, Abot S, Ganeshan H, Fallarme V, Patterson NB, Geall A, Weiss WR, Strobert E, Caro-Aquilar I, Lanar DE, Saul A, Martin LB, Gowda K, Morrissette CR, Kaslow DC, Carucci DJ, Galinski MR, Doolan DL. Induction of multi-antigen multi-stage immune responses against Plasmodium falciparum in rhesus monkeys, in the absence of antigen interference, with heterologous DNA prime/poxvirus boost immunization. Malar J 2007; 6:135. [PMID: 17925026 PMCID: PMC2147027 DOI: 10.1186/1475-2875-6-135] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2007] [Accepted: 10/09/2007] [Indexed: 12/04/2022] Open
Abstract
The present study has evaluated the immunogenicity of single or multiple Plasmodium falciparum (Pf) antigens administered in a DNA prime/poxvirus boost regimen with or without the poloxamer CRL1005 in rhesus monkeys. Animals were primed with PfCSP plasmid DNA or a mixture of PfCSP, PfSSP2/TRAP, PfLSA1, PfAMA1 and PfMSP1-42 (CSLAM) DNA vaccines in PBS or formulated with CRL1005, and subsequently boosted with ALVAC-Pf7, a canarypox virus expressing the CSLAM antigens. Cell-mediated immune responses were evaluated by IFN-γ ELIspot and intracellular cytokine staining, using recombinant proteins and overlapping synthetic peptides. Antigen-specific and parasite-specific antibody responses were evaluated by ELISA and IFAT, respectively. Immune responses to all components of the multi-antigen mixture were demonstrated following immunization with either DNA/PBS or DNA/CRL1005, and no antigen interference was observed in animals receiving CSLAM as compared to PfCSP alone. These data support the down-selection of the CSLAM antigen combination. CRL1005 formulation had no apparent effect on vaccine-induced T cell or antibody responses, either before or after viral boost. In high responder monkeys, CD4+IL-2+ responses were more predominant than CD8+ T cell responses. Furthermore, CD8+ IFN-γ responses were detected only in the presence of detectable CD4+ T cell responses. Overall, this study demonstrates the potential for multivalent Pf vaccines based on rational antigen selection and combination, and suggests that further formulation development to increase the immunogenicity of DNA encoded antigens is warranted.
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Affiliation(s)
- George Jiang
- Malaria Program, Naval Medical Research Center, Silver Spring, MD 20910-7500, USA.
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10
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Daubenberger CA, Spirig R, Patarroyo ME, Pluschke G. Flow cytometric analysis on cross-reactivity of human-specific CD monoclonal antibodies with splenocytes of Aotus nancymaae, a non-human primate model for biomedical research. Vet Immunol Immunopathol 2007; 119:14-20. [PMID: 17644187 DOI: 10.1016/j.vetimm.2007.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The reactivity of 204 monoclonal antibodies (mAb) out of 377 commercially available antibodies collected by the animal homologue group of the HLAD8 was analyzed by single colour flow cytometry. Most of these mAb were originally developed against human cell surface molecules. Fifty-eight mAb (28%) showed reactivity with spleen cells of Aotus nancymaae, a non-human primate animal model in biomedical research. Out of these 58 mAb, 22 also showed reactivity with mononuclear cells derived from rhesus macaques and cynomolgus monkeys indicating that the epitopes recognized are evolutionary conserved between human, Old and New World monkeys. This novel panel of A. nancymaae reactive mAb will increase the potential to explore complex host-pathogen interactions in non-human primate animal models, particularly in malaria vaccine research.
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Affiliation(s)
- Claudia A Daubenberger
- Swiss Tropical Institute, Department of Medical Parasitology and Biology of Infection, Molecular Immunology, Socinstrasse 57, 4002 Basel, Switzerland.
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11
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Girard MP, Reed ZH, Friede M, Kieny MP. A review of human vaccine research and development: malaria. Vaccine 2006; 25:1567-80. [PMID: 17045367 DOI: 10.1016/j.vaccine.2006.09.074] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2006] [Accepted: 09/25/2006] [Indexed: 11/18/2022]
Abstract
The last several years have seen significant progress in the development of vaccines against malaria. Most recently, proof-of-concept of vaccine-induced protection from malaria infection and disease was demonstrated in African children. Pursued by various groups and on many fronts, several other candidate vaccines are in early clinical trials. Yet, despite the optimism and promise, an effective malaria vaccine is not yet available, in part because of the lack of understanding of the types of immune responses needed for protection, added to the difficulty of identifying, selecting and producing the appropriate protective antigens from a parasite with a genome of well over five thousand genes and to the frequent need to enhance the immunogenicity of purified antigens through the use of novel adjuvants or delivery systems. Insufficient clinical trial capacity and normative research functions such as local ethical committee reviews also contribute to slow down the development process. This article attempts to summarize the state of the art of malaria vaccine development.
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Affiliation(s)
- Marc P Girard
- University Paris 7, 39 rue Seignemartin, FR-69008 Lyon, France.
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12
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Wang J, Nguyen V, Glen J, Henderson B, Saul A, Miller LH. Improved yield of recombinant merozoite Surface protein 3 (MSP3) from Pichia pastoris using chemically defined media. Biotechnol Bioeng 2005; 90:838-47. [PMID: 15849695 DOI: 10.1002/bit.20491] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Plasmodium falciparum merozoite surface protein 3 (MSP3) is a leading blood-stage malaria vaccine candidate. Vaccination with Pichia pastoris derived recombinant MSP3 protected Aotus nacymai monkeys from the parasite's lethal challenge and the post-challenge antibody titer against MSP3 correlated with protection. In our preliminary attempts to produce this vaccine in fermentors, little or no expression of MSP3 was observed in chemically defined media, although the same P. pastoris strain produced MSP3 in complex media. Our goal is to develop a Phase I/II clinical manufacturing process in completely chemically defined media because of the concern of potential prion contamination in complex media containing animal derived products. Here, we report our investigations into various factors to improve the yield of MSP3 in defined media. We found that an induction pH (pH(i)) 6.8 yielded MSP3 at 434 mg/L whereas there was no product at pH(i)< or = 5, though cell growth was the same in all pH(i) levels examined. High levels of NH(4) (+) consumed at pH(i) 6.8 were directly correlated to the enhanced MSP3 production. Furthermore, an additional 3.5-fold increase in the yield of MSP3 was obtained by addition of casamino acids at pH(i) 6.8. No direct correlation was observed between protease activity in the culture supernatants and lack of MSP3 expression. Neither high P. pastoris biomass generated at a high specific growth rate (0.04/h) nor low induction temperatures during induction improved yield. Nitrogen source was the most important factor affecting expression of MSP3 in defined media.
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Affiliation(s)
- Jin Wang
- Malaria Vaccine Development Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 5640 Fishers Lane, Rockville, Maryland 20852, USA.
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13
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Barrero CA, Delgado G, Sierra AY, Silva Y, Parra-Lopez C, Patarroyo MA. Gamma interferon levels and antibody production induced by two PvMSP-1 recombinant polypeptides are associated with protective immunity against P. vivax in Aotus monkeys. Vaccine 2005; 23:4048-53. [PMID: 15893858 DOI: 10.1016/j.vaccine.2005.02.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2004] [Accepted: 02/08/2005] [Indexed: 11/21/2022]
Abstract
Effector mechanisms responsible for providing protective immunity against Plasmodium vivax (Pv) infection were examined in Aotus monkeys vaccinated with two Pv Merozoite Surface Protein-1 (PvMSP-1) recombinant polypeptides that had previously been shown to protect vaccines against parasite challenge. Vaccine efficacy was reproducible in this trial, showing that one out of the five monkeys immunised with the recombinant protein mixture was partially protected while three others controlled parasitaemia. Antibodies reactive to the parasite's native proteins, the recombinant polypeptides and peptides spanning both recombinant fragments were detected in most vaccinees. Despite substantial Peripheral Blood Mononuclear Cell (PBMC) antigen-specific cellular proliferation not being detected, high rPvMSP-1(20) specific gamma interferon (IFN-gamma) production was found in the three animals that controlled parasitaemia. Altogether the results suggest that antibody titres and antigen-specific IFN-gamma production mediate protective immunity against P. vivax.
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Affiliation(s)
- Carlos A Barrero
- Molecular Biology Department, Fundacion Instituto de Inmunologia de Colombia, Carrera 50 # 26-00, Bogota, Colombia
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14
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Moncada CA, Guerrero E, Cardenas P, Suarez CF, Patarroyo ME, Patarroyo MA. The T-cell receptor in primates: identifying and sequencing new owl monkey TRBV gene sub-groups. Immunogenetics 2005; 57:42-52. [PMID: 15711805 DOI: 10.1007/s00251-004-0758-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2004] [Revised: 11/22/2004] [Indexed: 10/25/2022]
Abstract
The New World primate Aotus nancymaae (owl monkey) has been shown to be an excellent experimental model when studying malarial parasites. Characterising the T-cell receptor (TR) alphabeta repertoire by means of the different variable beta (TRBV) genes displayed contributes to a better understanding of these lymphocytes' role in the response against several malarial antigens. This study describes identifying and characterising eleven new TRBV gene sub-groups in cDNA from Aotus nancymaae's peripheral blood lymphocytes; these 11 gene sequences displayed homology to the previously reported human TRBV3, TRBV10, TRBV11, TRBV14, TRBV18, TRBV19, TRBV20, TRBV25, TRBV27, TRBV29 and TRBV30 sub-groups, resulting in 83% overall homology at the amino acid level. An additional Aotus sequence was found having similarity with the human TRBJ-2-7*01 gene. Evolutionary relationships amongst these sequences and the homologous genes from both New and Old World primates have shown that the TRBV repertoire has been maintained in the species being studied, displaying varying association patterns and substitution rates, depending on the sub-group being studied. The degree of identity observed when comparing human and Aotus genes suggests that these species might have a similar TRBV repertoire.
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Affiliation(s)
- Camilo A Moncada
- Molecular Biology Department, Fundacion Instituto de Inmunologia de Colombia (FIDIC), Colombia, South America
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15
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Darko CA, Angov E, Collins WE, Bergmann-Leitner ES, Girouard AS, Hitt SL, McBride JS, Diggs CL, Holder AA, Long CA, Barnwell JW, Lyon JA. The clinical-grade 42-kilodalton fragment of merozoite surface protein 1 of Plasmodium falciparum strain FVO expressed in Escherichia coli protects Aotus nancymai against challenge with homologous erythrocytic-stage parasites. Infect Immun 2005; 73:287-97. [PMID: 15618165 PMCID: PMC538964 DOI: 10.1128/iai.73.1.287-297.2005] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 42-kDa fragment from the C terminus of major merozoite surface protein 1 (MSP1) is among the leading malaria vaccine candidates that target infection by asexual erythrocytic-stage malaria parasites. The MSP1(42) gene fragment from the Vietnam-Oak Knoll (FVO) strain of Plasmodium falciparum was expressed as a soluble protein in Escherichia coli and purified according to good manufacturing practices. This clinical-grade recombinant protein retained some important elements of correct structure, as it was reactive with several functional, conformation-dependent monoclonal antibodies raised against P. falciparum malaria parasites, it induced antibodies (Abs) that were reactive to parasites in immunofluorescent Ab tests, and it induced strong growth and invasion inhibitory antisera in New Zealand White rabbits. The antigen quality was further evaluated by vaccinating Aotus nancymai monkeys and challenging them with homologous P. falciparum FVO erythrocytic-stage malaria parasites. The trial included two control groups, one vaccinated with the sexual-stage-specific antigen of Plasmodium vivax, Pvs25, as a negative control, and the other vaccinated with baculovirus-expressed MSP1(42) (FVO) as a positive control. Enzyme-linked immunosorbent assay (ELISA) Ab titers induced by E. coli MSP1(42) were significantly higher than those induced by the baculovirus-expressed antigen. None of the six monkeys that were vaccinated with the E. coli MSP1(42) antigen required treatment for uncontrolled parasitemia, but two required treatment for anemia. Protective immunity in these monkeys correlated with the ELISA Ab titer against the p19 fragment and the epidermal growth factor (EGF)-like domain 2 fragment of MSP1(42), but not the MSP1(42) protein itself or the EGF-like domain 1 fragment. Soluble MSP1(42) (FVO) expressed in E. coli offers excellent promise as a component of a vaccine against erythrocytic-stage falciparum malaria.
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Affiliation(s)
- Christian A Darko
- Department of Immunology, Walter Reed Army Institute of Research, 503 Robert Grant Ave., Silver Spring, MD 20910, USA
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Chen Q, Pettersson F, Vogt AM, Schmidt B, Ahuja S, Liljeström P, Wahlgren M. Immunization with PfEMP1-DBL1alpha generates antibodies that disrupt rosettes and protect against the sequestration of Plasmodium falciparum-infected erythrocytes. Vaccine 2004; 22:2701-12. [PMID: 15246600 DOI: 10.1016/j.vaccine.2004.02.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2003] [Revised: 01/30/2004] [Accepted: 02/03/2004] [Indexed: 10/26/2022]
Abstract
A family of parasite antigens known as Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is believed to play an important role in the binding of infected erythrocytes to host receptors in the micro-vasculature. Available data advocates the existence of a subset of very adhesive (rosetting, auto-agglutinating) and antigenic PfEMP1s implicated as virulence factors. Serum antibodies that disrupt rosettes are rarely found in children with severe malaria but are frequent in those with mild disease suggesting that they may be protective. Here we have developed a Semliki forest virus (SFV) vaccine construct with a recombinant gene (mini-var gene) encoding a mini-PfEMP1 (DBL1alpha-TM-ATS) obtained from a particularly antigenic and rosetting parasite (FCR3S1.2). The mini-PfEMP1 is presented to the host mimicking the location of the native molecule at the infected erythrocyte surface. Antibodies generated by a regimen of priming with SFV RNA particles and boosting with a recombinant protein recognize the infected erythrocyte surface (immuno-fluorescence/rosette-disruption) and prevent the sequestration of P. falciparum-infected erythrocytes in an in vivo model of severe malaria. The data prove the involvement of DBL1alpha in the adhesion of infected- and uninfected erythrocytes and the role of rosette-disruptive antibodies in preventing these cellular interactions. The work supports the use of DBL1alpha in a vaccine again severe malaria.
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Affiliation(s)
- Qijun Chen
- Microbiology and Tumorbiology Centre, Karolinska Institutet, Box 280, SE-171 77 Stockholm, Sweden.
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Carvalho LJM, Oliveira SG, Theisen M, Alves FA, Andrade MCR, Zanini GM, Brígido MCO, Oeuvray C, Póvoa MM, Muniz JAPC, Druilhe P, Daniel-Ribeiro CT. Immunization of Saimiri sciureus monkeys with Plasmodium falciparum merozoite surface protein-3 and glutamate-rich protein suggests that protection is related to antibody levels. Scand J Immunol 2004; 59:363-72. [PMID: 15049780 DOI: 10.1111/j.0300-9475.2004.01409.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The immunogenicity and protective efficacy of various antigen-adjuvant formulations derived either from the merozoite-surface protein-3 (MSP-3) or the glutamate-rich protein (GLURP) of Plasmodium falciparum were evaluated in Saimiri sciureus monkeys. These proteins were selected for immunogenicity studies based primarily on their capacity of inducing an antibody-dependent cellular inhibition effect on parasite growth. Some of the S. sciureus monkeys immunized with MSP-3(212-380)-AS02 or GLURP(27-500)-alum were able to fully or partially control parasitaemia upon an experimental P. falciparum [Falciparum Uganda Palo Alto (FUP-SP) strain] blood-stage infection, and this protection was related to the prechallenge antibody titres induced. The data are indicative that MSP-3 and GLURP can induce protective immunity against an experimental P. falciparum infection using adjuvants that are acceptable for human use and this should trigger further studies with those new antigens.
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Affiliation(s)
- L J M Carvalho
- Laboratory of Malaria Research, Department of Immunology, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.
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Carvalho LJDM, Alves FA, de Oliveira SG, do Valle RDR, Fernandes AAM, Muniz JAPC, Daniel-Ribeiro CT. Severe anemia affects both splenectomized and non-splenectomized Plasmodium falciparum-infected Aotus infulatus monkeys. Mem Inst Oswaldo Cruz 2003; 98:679-86. [PMID: 12973537 DOI: 10.1590/s0074-02762003000500016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Severe anemia is the earliest and a frequently fatal complication of Plasmodium falciparum infection. Here we describe Aotus infulatus as a primate model suitable to study this malaria complication. Both non-splenectomized and splenectomized monkeys receiving different inocula of P. falciparum FVO strain presented large (> 50%) decreases in hematocrit values during infection. Non-splenectomized animals were able to control parasite growth (parasitemia did not exceed 4%), but they had to be treated because of severe anemia. Three of 4 splenectomized monkeys did not control parasitemia and were treated, but developed severe anemia after treatment when presenting a negative blood film. Destruction of parasitized red blood cells alone cannot account for the degree of anemia. Non-splenectomized monkeys repeatedly infected with homologous parasites became rapidly and progressively resistant to reinfection and to the development of severe anemia. The data presented here point to A. infulatus as a suitable model for studying the pathogenesis of severe malarial infection.
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Affiliation(s)
- Leonardo J de Moura Carvalho
- Laboratório de Pesquisas em Malária, Departamento de Imunologia, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, Brasil.
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19
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Mérien F, Lavergne A, Behr C, Contamin H. Sequencing and analysis of genomic DNA and cDNA encoding TNF-alpha in the squirrel monkey (Saimiri sciureus). Vet Immunol Immunopathol 2003; 92:37-43. [PMID: 12628762 DOI: 10.1016/s0165-2427(03)00018-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
If a number of cytokines and growth factors that have been characterized from human cells were investigated in non-human primates, results from such approaches would allow the development of assays to detect and quantitate cytokines in experimental models. Tumor necrosis factor-alpha (TNF-alpha) is an important pluripotent cytokine which plays a crucial role in host defense. As yet, no complete molecular data have been reported for the squirrel monkey TNF-alpha. Polymerase chain reaction (PCR) primers were used to trace introns, by comparing product sizes obtained using cDNA and genomic DNA as templates. The genomic DNA is composed of four exons and three introns with 1793 nucleotides. The corresponding cDNA is 702 nucleotides and phylogenetic analysis showed that the Saimiri sciureus was most closely related to that of the genus Aotus, a new-world primate, compared to old-world primates (genus Macaca and Papio). The deduced TNF-alpha protein consists of 233 amino acids with 82% identity to human, 95% to new-world monkeys and 79% to old-world monkeys. The cloned TNF-alpha cDNA will be useful to quantitate TNF-alpha at the mRNA level.
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Affiliation(s)
- Fabrice Mérien
- Centre de Primatologie, Institut Pasteur de la Guyane, BP 6010, 97306 Cayenne Cedex, French Guiana.
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Herrera S, Perlaza BL, Bonelo A, Arévalo-Herrera M. Aotus monkeys: their great value for anti-malaria vaccines and drug testing. Int J Parasitol 2002; 32:1625-35. [PMID: 12435447 DOI: 10.1016/s0020-7519(02)00191-1] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Non-human primates represent a valuable resource for testing potential vaccines candidates and drugs for human use. Malaria remains one of the greatest burdens for the humanity represented by approximately 500 million new clinical cases per year worldwide and at least two million deaths caused annually. Additional control measures such as vaccines and new anti-malarial compounds are therefore urgently needed. Safety and protective efficacy studies in animal models are critical steps for vaccines and drugs development and primate models are probably the most appropriate for this purpose. Although Aotus genus provides several species susceptible to both Plasmodium falciparum and Plasmodium vivax, having different susceptibility to malaria, Aotus lemurinus griseimembra represents the best current malaria primate model because of its high susceptibility to infection by blood forms and sporozoites of both species of Plasmodium. Although the ultimate validation of this model depends upon human trials, over the past two decades these monkeys have proved very useful to test multiple malaria vaccine candidates prior to trials in humans. A good correlation between the B- and T-cell epitopes recognised by humans and by immunised monkeys has been documented, and cross reactivity between reagents for human and Aotus cytokines and lymphocyte markers have been identified and are facilitating the selection of vaccine candidates for clinical trials. Aotus also represents a good model for the screening of anti-malarial drugs and the understanding of malaria pathogenesis as well. In view of the decreasing availability of these primates, breeding programs and biomedical research facilities must be improved in countries of primate origin.
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Affiliation(s)
- Sócrates Herrera
- Instituto de Inmunologia, Universidad del Valle, AA 25574 Cali, Colombia.
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Carvalho LJM, Daniel-Ribeiro CT, Goto H. Malaria vaccine: candidate antigens, mechanisms, constraints and prospects. Scand J Immunol 2002; 56:327-43. [PMID: 12234254 DOI: 10.1046/j.1365-3083.2002.01160.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
More than 30 years after the first report of successful vaccination against malaria using radiation-attenuated sporozoites, an effective malaria vaccine is not yet available. However, field and experimental data indicate that it can be developed. An astonishing amount of data has accumulated concerning parasite biology, host-parasite interactions, immunity and escape mechanisms, targets and modulators of immune responses. Nevertheless, so far this knowledge has not been enough to make us understand how to properly manipulate the whole system to build an effective vaccine. In this article, we describe candidate antigens, mechanisms, targets and trials performed with potential malaria vaccines and discuss the approaches, in vivo and in vitro models, constraints and how technologies such as DNA vaccination, genomics/proteomics and reverse immunogenetics are providing exciting results and opening new doors to make malaria vaccine a reality.
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Affiliation(s)
- L J M Carvalho
- Department of Immunology, WHO Collaborating Centre for Research and Training in the Immunology of Parasitic Diseases, Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil.
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Caro-Aguilar I, Rodríguez A, Calvo-Calle JM, Guzmán F, De la Vega P, Patarroyo ME, Galinski MR, Moreno A. Plasmodium vivax promiscuous T-helper epitopes defined and evaluated as linear peptide chimera immunogens. Infect Immun 2002; 70:3479-92. [PMID: 12065487 PMCID: PMC128085 DOI: 10.1128/iai.70.7.3479-3492.2002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clinical trials of malaria vaccines have confirmed that parasite-derived T-cell epitopes are required to elicit consistent and long-lasting immune responses. We report here the identification and functional characterization of six T-cell epitopes that are present in the merozoite surface protein-1 of Plasmodium vivax (PvMSP-1) and bind promiscuously to four different HLA-DRB1* alleles. Each of these peptides induced lymphoproliferative responses in cells from individuals with previous P. vivax infections. Furthermore, linear-peptide chimeras containing the promiscuous PvMSP-1 T-cell epitopes, synthesized in tandem with the Plasmodium falciparum immunodominant circumsporozoite protein (CSP) B-cell epitope, induced high specific antibody titers, cytokine production, long-lasting immune responses, and immunoglobulin G isotype class switching in BALB/c mice. A linear-peptide chimera containing an allele-restricted P. falciparum T-cell epitope with the CSP B-cell epitope was not effective. Two out of the six promiscuous T-cell epitopes exhibiting the highest anti-peptide response also contain B-cell epitopes. Antisera generated against these B-cell epitopes recognize P. vivax merozoites in immunofluorescence assays. Importantly, the anti-peptide antibodies generated to the CSP B-cell epitope inhibited the invasion of P. falciparum sporozoites into human hepatocytes. These data and the simplicity of design of the chimeric constructs highlight the potential of multimeric, multistage, and multispecies linear-peptide chimeras containing parasite promiscuous T-cell epitopes for malaria vaccine development.
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Affiliation(s)
- Ivette Caro-Aguilar
- Fundación Instituto de Inmunología de Colombia (FIDIC), Santafé de Bogotá, Colombia
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Abstract
Malaria causes much physical and economic hardship in tropical regions, particularly in communities where medical care is rudimentary. Should a vaccine be developed, it is the residents of these areas that stand to benefit the most. But the vaccine, which has been promised to be 'just round the corner' for many years, remains elusive. It is important to ask why this is so, when effective vaccines exist for many other infectious diseases. What are the reasons for the slow rate of progress, and what has been learned from the first clinical trials of candidate malaria vaccines? What are the remaining challenges, and what strategies can be pursued to address them?
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Affiliation(s)
- Thomas L Richie
- Malaria Program, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, Maryland 20910-7500, USA.
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Stowers AW, Chen Lh LH, Zhang Y, Kennedy MC, Zou L, Lambert L, Rice TJ, Kaslow DC, Saul A, Long CA, Meade H, Miller LH. A recombinant vaccine expressed in the milk of transgenic mice protects Aotus monkeys from a lethal challenge with Plasmodium falciparum. Proc Natl Acad Sci U S A 2002; 99:339-44. [PMID: 11752405 PMCID: PMC117562 DOI: 10.1073/pnas.012590199] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two strains of transgenic mice have been generated that secrete into their milk a malaria vaccine candidate, the 42-kDa C-terminal portion of Plasmodium falciparum merozoite surface protein 1 (MSP1(42)). One strain secretes an MSP1(42) with an amino acid sequence homologous to that of the FVO parasite line, the other an MSP1(42) where two putative N-linked glycosylation sites in the FVO sequence have been removed. Both forms of MSP1(42) were purified from whole milk to greater than 91% homogeneity at high yields. Both proteins are recognized by a panel of monoclonal antibodies and have identical N termini, but are clearly distinguishable by some biochemical properties. These two antigens were each emulsified with Freund's adjuvant and used to vaccinate Aotus nancymai monkeys, before challenge with the homologous P. falciparum FVO parasite line. Vaccination with a positive control molecule, a glycosylated form of MSP1(42) produced in the baculovirus expression system, successfully protected five of six monkeys. By contrast, vaccination with the glycosylated version of milk-derived MSP1(42) conferred no protection compared with an adjuvant control. Vaccination with the nonglycosylated, milk-derived MSP1(42) successfully protected the monkeys, with 4/5 animals able to control an otherwise lethal infection with P. falciparum compared with 1/7 control animals. Analysis of the different vaccines used suggested that the differing nature of the glycosylation patterns may have played a critical role in determining efficacy. This study demonstrates the potential for producing efficacious malarial vaccines in transgenic animals.
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Affiliation(s)
- Anthony W Stowers
- Malaria Vaccine Development Unit, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Rockville, MD 20852, USA.
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