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Lissom A, Megnekou R, Tchouangueu TF, Ngu L, Djontu JC, Ouambo HF, Sanders C, Tchadji JC, Sake CS, Tchuandom SB, Bawage S, Okoli AS, Park CG, Waffo AB, Godwin NW. Specific antibody responses to Qβ-displayed Plasmodium falciparum-derived UB05 and MSP3 proteins in mother-neonate couples. Scand J Immunol 2024:e13404. [PMID: 39155843 DOI: 10.1111/sji.13404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 07/22/2024] [Accepted: 08/01/2024] [Indexed: 08/20/2024]
Abstract
Malaria blood-stage parasite is a critical pathogenic stage responsible for serious adverse outcomes in pregnant women and their neonates. Immunoglobulin G (IgG) antibody responses specific to various asexual blood-stage antigens were well reported in non-pregnant individuals. However, little is still known during placental malaria. To assess the antibody responses specific to Plasmodium falciparum-derived MSP3 and UB05 malaria vaccine candidates in mother-neonate couples, mother's peripheral blood and neonate's cord blood samples were collected at delivery. After malaria diagnostic, plasma levels of IgG and IgG subclass responses specific to UB05, MSP3 and UB05-MSP3 were determined using ELISA. As outcomes, both mothers and neonates had significantly higher IgG responses to UB05 and UB05-MSP3 compared to anti-MSP3 IgG (p < 0.05), irrespective of malaria status. Significant negative correlations were observed between IgG levels specific to the three antigens and parasitaemia (p < 0.01). Anti-UB05 and anti-UB05-MSP3 IgG levels in neonates showed a significant positive correlation with the corresponding mothers' antibodies (rs = 0.25 with p = 0.04; rs = 0.31 with p = 0.01, respectively). UB05MSP3-specific IgG3 and IgG1 subclass responses were significantly higher than the IgG4 subclass (p < 0.01). The neonates IgG1 and IgG3 levels positively correlated with the corresponding antibody subclasses of mothers. These findings suggest an association between UB05 and UB05-MSP3-specific antibody responses and malaria control during pregnancy. Maternal-foetal transfer of MSP3 and UB05-specific IgG occurs during pregnancy, suggesting the interest in the future malaria vaccination strategies in pregnant women to generate early protective immunity in baby against malaria.
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Affiliation(s)
- Abel Lissom
- Laboratory of Vaccinology/Biobanking of Chantal BIYA International Reference Center for (CIRCB), Yaounde, Cameroon
- Department of Zoology, Faculty of Science of the University of Bamenda, Bamenda, Cameroon
| | - Rosette Megnekou
- Department of Animal Biology and Physiology, University of Yaounde I, Yaoundé, Cameroon
- Laboratory of Immunology of Biotechnology Center, University of Yaounde I, Yaounde, Cameroon
| | - Thibau Flaurant Tchouangueu
- Laboratory of Vaccinology/Biobanking of Chantal BIYA International Reference Center for (CIRCB), Yaounde, Cameroon
- Department of Microbiology Hematology and Immunology, Faculty of Medicine and Pharmaceutical Science, University of Dschang, Dschang, Cameroon
| | - Loveline Ngu
- Laboratory of Vaccinology/Biobanking of Chantal BIYA International Reference Center for (CIRCB), Yaounde, Cameroon
- Department of Biochemistry of the Faculty of Science, University of Yaounde I, Yaoundé, Cameroon
| | - Jean Claude Djontu
- Laboratory of Immunology of Biotechnology Center, University of Yaounde I, Yaounde, Cameroon
| | - Herve Fotso Ouambo
- Laboratory of Vaccinology/Biobanking of Chantal BIYA International Reference Center for (CIRCB), Yaounde, Cameroon
| | - Carrie Sanders
- Department of Biological Sciences, College STEM, Montgomery, Alabama, USA
| | - Jules Colince Tchadji
- Laboratory of Vaccinology/Biobanking of Chantal BIYA International Reference Center for (CIRCB), Yaounde, Cameroon
- Department of Animal Biology and Physiology, University of Yaounde I, Yaoundé, Cameroon
| | - Carole Stephanie Sake
- Laboratory of Vaccinology/Biobanking of Chantal BIYA International Reference Center for (CIRCB), Yaounde, Cameroon
- Department of Microbiology of the Faculty of Science, University of Yaounde I, Yaoundé, Cameroon
| | - Salomon Bonsi Tchuandom
- Laboratory of Vaccinology/Biobanking of Chantal BIYA International Reference Center for (CIRCB), Yaounde, Cameroon
| | - Swapnil Bawage
- Department of Biological Sciences, College STEM, Montgomery, Alabama, USA
- Center for NanoBiotechnology Research, Montgomery, Alabama, USA
| | | | - Chae Gyu Park
- Laboratory of Immunology, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Alain Bopda Waffo
- Department of Biological Sciences, College STEM, Montgomery, Alabama, USA
- Center for NanoBiotechnology Research, Montgomery, Alabama, USA
- Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Nchinda Wapimewah Godwin
- Laboratory of Vaccinology/Biobanking of Chantal BIYA International Reference Center for (CIRCB), Yaounde, Cameroon
- Panafrican Center of Excellence for Clinical and Translational Sciences (PANECTS), Yaounde, Cameroon
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Natural Plasmodium falciparum Infection Stimulates Human Antibodies to MSP1 Epitopes Identified in Mice Infection Models upon Non-Natural Modified Peptidomimetic Vaccination. Molecules 2023; 28:molecules28062527. [PMID: 36985500 PMCID: PMC10057838 DOI: 10.3390/molecules28062527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/28/2023] [Accepted: 03/03/2023] [Indexed: 03/12/2023] Open
Abstract
(1) Background: Malaria, a vector-borne infectious disease, is caused by parasites of the Plasmodium genus, responsible for increased extreme morbidity and mortality rates. Despite advances in approved vaccines, full protection has not yet been achieved upon vaccination, thus the development of more potent and safe immuno-stimulating agents for malaria prevention is a goal to be urgently accomplished. We have focused our research on a strategy to identify Plasmodium spp. epitopes by naturally acquired human antibodies and rodent malaria infection models immunized with site-directed non-natural antigens. (2) Methods: Some predictive algorithms and bioinformatics tools resembling different biological environments, such as phagosome-lysosome proteolytic degradation, affinity, and the high frequency of malaria-resistant and -sensitive HLA-II alleles were regarded for the proper selection of epitopes and potential testing. Each epitope’s binding profile to both host cells and HLA-II molecules was considered for such initial screening. (3) Results: Once selected, we define each epitope-peptide to be synthesized in terms of size and hydrophobicity, and introduced peptide-bond surrogates and non-natural amino acids in a site-directed fashion, and then they were produced by solid-phase peptide synthesis. Molecules were then tested by their antigenic and immunogenic properties compared to human sera from Colombian malaria-endemic areas. The antigenicity and protective capacity of each epitope-peptide in a rodent infection model were examined. The ability of vaccinated mice after being challenged with P. berghei ANKA and P. yoelii 17XL to control malaria led to the determination of an immune stimulation involving Th1 and Th1/Th2 mechanisms. In silico molecular dynamics and modeling provided some interactions insights, leading to possible explanations for protection due to immunization. (4) Conclusions: We have found evidence for proposing MSP1-modified epitopes to be considered as neutralizing antibody stimulators that are useful as probes for the detection of Plasmodium parasites, as well as for sub-unit components of a site-directed designed malaria vaccine candidate.
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3
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A Chimeric Plasmodium vivax Merozoite Surface Protein Antibody Recognizes and Blocks Erythrocytic P. cynomolgi Berok Merozoites In Vitro. Infect Immun 2021; 89:IAI.00645-20. [PMID: 33199351 DOI: 10.1128/iai.00645-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 01/22/2023] Open
Abstract
Research on erythrocytic Plasmodium vivax merozoite antigens is critical for identifying potential vaccine candidates in reducing P. vivax disease. However, many P. vivax studies are constrained by its inability to undergo long-term culture in vitro Conserved across all Plasmodium spp., merozoite surface proteins are essential for invasion into erythrocytes and highly expressed on erythrocytic merozoites, thus making it an ideal vaccine candidate. In clinical trials, the P. vivax merozoite surface protein 1 (PvMSP1-19) vaccine candidate alone has shown to have limited immunogenicity in patients; hence, we incorporate the highly conserved and immunogenic C terminus of both P. vivax merozoite surface protein 8 (PvMSP8) and PvMSP1-19 to develop a multicomponent chimeric protein rPvMSP8+1 for immunization of mice. The resulted chimeric rPvMSP8+1 antibody was shown to recognize native protein MSP8 and MSP1-19 of mature P. vivax schizonts. In the immunized mice, an elevated antibody response was observed in the rPvMSP8+1-immunized group compared to that immunized with single-antigen components. In addition, we examined the growth inhibition of these antibodies against Plasmodium cynomolgi (Berok strain) parasites, which is phylogenetically close to P. vivax and sustains long-term culture in vitro Similarly, the chimeric anti-rPvMSP8+1 antibodies recognize P. cynomolgi MSP8 and MSP1-19 on mature schizonts and showed strong inhibition in vitro via growth inhibition assay. This study provides support for a new multiantigen-based paradigm rPvMSP8+1 to explore potential chimeric vaccine candidates against P. vivax malaria using sister species P. cynomolgi.
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McCaffery JN, Fonseca JA, Singh B, Cabrera-Mora M, Bohannon C, Jacob J, Arévalo-Herrera M, Moreno A. A Multi-Stage Plasmodium vivax Malaria Vaccine Candidate Able to Induce Long-Lived Antibody Responses Against Blood Stage Parasites and Robust Transmission-Blocking Activity. Front Cell Infect Microbiol 2019; 9:135. [PMID: 31119106 PMCID: PMC6504793 DOI: 10.3389/fcimb.2019.00135] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/15/2019] [Indexed: 12/13/2022] Open
Abstract
Malaria control and interventions including long-lasting insecticide-treated nets, indoor residual spraying, and intermittent preventative treatment in pregnancy have resulted in a significant reduction in the number of Plasmodium falciparum cases. Considerable efforts have been devoted to P. falciparum vaccines development with much less to P. vivax. Transmission-blocking vaccines, which can elicit antibodies targeting Plasmodium antigens expressed during sexual stage development and interrupt transmission, offer an alternative strategy to achieve malaria control. The post-fertilization antigen P25 mediates several functions essential to ookinete survival but is poorly immunogenic in humans. Previous clinical trials targeting this antigen have suggested that conjugation to a carrier protein could improve the immunogenicity of P25. Here we report the production, and characterization of a vaccine candidate composed of a chimeric P. vivax Merozoite Surface Protein 1 (cPvMSP1) genetically fused to P. vivax P25 (Pvs25) designed to enhance CD4+ T cell responses and its assessment in a murine model. We demonstrate that antibodies elicited by immunization with this chimeric protein recognize both the erythrocytic and sexual stages and are able to block the transmission of P. vivax field isolates in direct membrane-feeding assays. These findings provide support for the continued development of multi-stage transmission blocking vaccines targeting the life-cycle stage responsible for clinical disease and the sexual-stage development accountable for disease transmission simultaneously.
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Affiliation(s)
- Jessica N. McCaffery
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Jairo A. Fonseca
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, United States
| | - Balwan Singh
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Monica Cabrera-Mora
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Caitlin Bohannon
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Joshy Jacob
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, United States
| | - Myriam Arévalo-Herrera
- Caucaseco Scientific Research Center, Malaria Vaccine and Drug Development Center, Cali, Colombia
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, United States
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Parra M, Yang J, Weitner M, Derrick S, Yang A, Schmidt T, Singh B, Moreno A, Akkoyunlu M. TACI Contributes to Plasmodium yoelii Host Resistance by Controlling T Follicular Helper Cell Response and Germinal Center Formation. Front Immunol 2018; 9:2612. [PMID: 30473702 PMCID: PMC6237915 DOI: 10.3389/fimmu.2018.02612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/23/2018] [Indexed: 01/22/2023] Open
Abstract
The delay in parasite-specific B cell development leaves people in malaria endemic areas vulnerable to repeated Plasmodium infections. Here, we investigated the role of transmembrane activator and calcium-modulator and cyclophilin ligand interactor (TACI), a molecule involved in the generation of antigen-specific antibody secreting cells, in host response to non-lethal Plasmodium yoelii infection. We found that TACI deficiency not only resulted in higher peak parasitemia levels in P. yoelii challenged mice, but also led to a delay in parasite clearance and anti-P. yoelii Merozoite Surface Protein 1(C-terminal 19-kDa fragment [rMSP-119]) protein and anti-rMSP-119 and anti-P. yoelii IgG antibody development. There was also a delay in the generation of splenic high affinity antibody secreting cells that recognize rMSP-119 protein as compared to wild-type mice. Interestingly, coinciding with the delay in parasite clearance there was a delay in the resolution of T follicular helper (TFH) cell and germinal center (GC) B cell responses in TACI -/- mice. The persistence of TFH and GC B cells is likely a result of enhanced interaction between TFH and GC B cells because inducible costimulator ligand (ICOSL) expression was significantly higher on TACI -/- GC B cells than wild-type cells. The difference in the kinetics of GC reaction appeared to also impact the emergence of plasma cells (PC) because there was a delay in the generation of TACI -/- mice PC. Nevertheless, following the recovery from P. yoelii infection, TACI -/- and wild-type mice were both protected from a rechallenge infection. Establishment of protective B cell response was responsible for the resolution of parasitemia because B cells purified from recovered TACI -/- or wild-type mice were equally protective when introduced to naïve wild-type mice prior to P. yoelii challenge. Thus, despite the increased susceptibility of TACI -/- mice to P. yoelii infection and a delay in the development of protective antibody levels, TACI -/- mice are able to clear the infection and resist rechallenge infection.
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Affiliation(s)
- Marcela Parra
- US Food and Drug Administration, Division of Bacterial Allergenic and Parasitic Diseases, Center for Biologics Evaluation and Research, Silver Spring, MD, United States
| | - Jiyeon Yang
- US Food and Drug Administration, Division of Bacterial Allergenic and Parasitic Diseases, Center for Biologics Evaluation and Research, Silver Spring, MD, United States
| | - Megan Weitner
- US Food and Drug Administration, Division of Bacterial Allergenic and Parasitic Diseases, Center for Biologics Evaluation and Research, Silver Spring, MD, United States
| | - Steven Derrick
- US Food and Drug Administration, Division of Bacterial Allergenic and Parasitic Diseases, Center for Biologics Evaluation and Research, Silver Spring, MD, United States
| | - Amy Yang
- US Food and Drug Administration, Division of Bacterial Allergenic and Parasitic Diseases, Center for Biologics Evaluation and Research, Silver Spring, MD, United States
| | - Thomas Schmidt
- US Food and Drug Administration, Division of Bacterial Allergenic and Parasitic Diseases, Center for Biologics Evaluation and Research, Silver Spring, MD, United States
| | - Balwan Singh
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States.,Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States
| | - Mustafa Akkoyunlu
- US Food and Drug Administration, Division of Bacterial Allergenic and Parasitic Diseases, Center for Biologics Evaluation and Research, Silver Spring, MD, United States
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Fonseca JA, McCaffery JN, Kashentseva E, Singh B, Dmitriev IP, Curiel DT, Moreno A. A prime-boost immunization regimen based on a simian adenovirus 36 vectored multi-stage malaria vaccine induces protective immunity in mice. Vaccine 2017; 35:3239-3248. [PMID: 28483199 PMCID: PMC5522619 DOI: 10.1016/j.vaccine.2017.04.062] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 12/22/2022]
Abstract
Malaria remains a considerable burden on public health. In 2015, the WHO estimates there were 212 million malaria cases causing nearly 429,000 deaths globally. A highly effective malaria vaccine is needed to reduce the burden of this disease. We have developed an experimental vaccine candidate (PyCMP) based on pre-erythrocytic (CSP) and erythrocytic (MSP1) stage antigens derived from the rodent malaria parasite P. yoelii. Our protein-based vaccine construct induces protective antibodies and CD4+ T cell responses. Based on evidence that viral vectors increase CD8+ T cell-mediated immunity, we also have tested heterologous prime-boost immunization regimens that included human adenovirus serotype 5 vector (Ad5), obtaining protective CD8+ T cell responses. While Ad5 is commonly used for vaccine studies, the high prevalence of pre-existing immunity to Ad5 severely compromises its utility. Here, we report the use of the novel simian adenovirus 36 (SAd36) as a candidate for a vectored malaria vaccine since this virus is not known to infect humans, and it is not neutralized by anti-Ad5 antibodies. Our study shows that the recombinant SAd36PyCMP can enhance specific CD8+ T cell response and elicit similar antibody titers when compared to an immunization regimen including the recombinant Ad5PyCMP. The robust immune responses induced by SAd36PyCMP are translated into a lower parasite load following P. yoelii infectious challenge when compared to mice immunized with Ad5PyCMP.
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Affiliation(s)
- Jairo A Fonseca
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, United States; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307, United States
| | - Jessica N McCaffery
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, United States
| | - Elena Kashentseva
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 660 S. Euclid Ave., 4511 Forest Park Blvd, St. Louis, MO 63108, United States
| | - Balwan Singh
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, United States
| | - Igor P Dmitriev
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 660 S. Euclid Ave., 4511 Forest Park Blvd, St. Louis, MO 63108, United States
| | - David T Curiel
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 660 S. Euclid Ave., 4511 Forest Park Blvd, St. Louis, MO 63108, United States
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Road, Atlanta, GA 30329, United States; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307, United States.
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7
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Dinga JN, Njimoh DL, Kiawa B, Djikeng A, Nyasa RB, Nkuo-Akenji T, Pellé R, Titanji VPK. Differential T-cell responses to a chimeric Plasmodium falciparum antigen; UB05-09, correlates with acquired immunity to malaria. Parasite Immunol 2017; 38:303-16. [PMID: 27012849 DOI: 10.1111/pim.12318] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 03/22/2016] [Indexed: 12/29/2022]
Abstract
The development of a sterilizing and cost-effective vaccine against malaria remains a major problem despite recent advances. In this study, it is demonstrated that two antigens of P. falciparum UB05, UB09 and their chimera UB05-09 can serve as protective immunity markers by eliciting higher T-cell responses in malaria semi-immune subjects (SIS) than in frequently sick subjects (FSS) and could be used to distinguish these two groups. UB05, UB09 and UB05-09 were cloned, expressed in E. coli, purified and used to stimulate PBMCs isolated from 63 subjects in a malaria endemic area, for IFN-γ production, which was measured by the ELISpot assay. The polymorphism of UB09 gene in the malaria infected population was also studied by PCR/sequencing of the gene in P. falciparum field isolates. All three antigens were preferentially recognized by PBMCs from SIS. IFN-γ production induced by these antigens correlated with the absence of fever and parasitaemia. UB09 was shown to be relatively well-conserved in nature. It is concluded that UB05, UB09 and the chimera UB05-09 posses T-cell epitopes that are associated with protection against malaria and could thus be used to distinguish SIS from FSS eventhough acute infection with malaria has been shown to reduce cytokine production in some studies. Further investigations of these antigens as potential diagnostic and/or vaccine candidates for malaria are indicated.
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Affiliation(s)
- J N Dinga
- Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - D L Njimoh
- Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - B Kiawa
- Biosciences Eastern and Central Africa -International Livestock Research Institute-Hub, Nairobi, Kenya
| | - A Djikeng
- Biosciences Eastern and Central Africa -International Livestock Research Institute-Hub, Nairobi, Kenya
| | - R B Nyasa
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
| | - T Nkuo-Akenji
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
| | - R Pellé
- Biosciences Eastern and Central Africa -International Livestock Research Institute-Hub, Nairobi, Kenya
| | - V P K Titanji
- Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon.,Cameroon Christian University Institute, Bali, Cameroon
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8
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A chimeric protein-based malaria vaccine candidate induces robust T cell responses against Plasmodium vivax MSP1 19. Sci Rep 2016; 6:34527. [PMID: 27708348 PMCID: PMC5052570 DOI: 10.1038/srep34527] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 09/15/2016] [Indexed: 01/06/2023] Open
Abstract
The most widespread Plasmodium species, Plasmodium vivax, poses a significant public health threat. An effective vaccine is needed to reduce global malaria burden. Of the erythrocytic stage vaccine candidates, the 19 kDa fragment of the P. vivax Merozoite Surface Protein 1 (PvMSP119) is one of the most promising. Our group has previously defined several promiscuous T helper epitopes within the PvMSP1 protein, with features that allow them to bind multiple MHC class II alleles. We describe here a P. vivax recombinant modular chimera based on MSP1 (PvRMC-MSP1) that includes defined T cell epitopes genetically fused to PvMSP119. This vaccine candidate preserved structural elements of the native PvMSP119 and elicited cytophilic antibody responses, and CD4+ and CD8+ T cells capable of recognizing PvMSP119. Although CD8+ T cells that recognize blood stage antigens have been reported to control blood infection, CD8+ T cell responses induced by P. falciparum or P. vivax vaccine candidates based on MSP119 have not been reported. To our knowledge, this is the first time a protein based subunit vaccine has been able to induce CD8+ T cell against PvMSP119. The PvRMC-MSP1 protein was also recognized by naturally acquired antibodies from individuals living in malaria endemic areas with an antibody profile associated with protection from infection. These features make PvRMC-MSP1 a promising vaccine candidate.
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9
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Cabrera-Mora M, Fonseca JA, Singh B, Zhao C, Makarova N, Dmitriev I, Curiel DT, Blackwell J, Moreno A. A Recombinant Chimeric Ad5/3 Vector Expressing a Multistage Plasmodium Antigen Induces Protective Immunity in Mice Using Heterologous Prime-Boost Immunization Regimens. THE JOURNAL OF IMMUNOLOGY 2016; 197:2748-61. [PMID: 27574299 DOI: 10.4049/jimmunol.1501926] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 08/02/2016] [Indexed: 12/31/2022]
Abstract
An ideal malaria vaccine should target several stages of the parasite life cycle and induce antiparasite and antidisease immunity. We have reported a Plasmodium yoelii chimeric multistage recombinant protein (P. yoelii linear peptide chimera/recombinant modular chimera), engineered to express several autologous T cell epitopes and sequences derived from the circumsporozoite protein and the merozoite surface protein 1. This chimeric protein elicits protective immunity, mediated by CD4(+) T cells and neutralizing Abs. However, experimental evidence, from pre-erythrocytic vaccine candidates and irradiated sporozoites, has shown that CD8(+) T cells play a significant role in protection. Recombinant viral vectors have been used as a vaccine platform to elicit effective CD8(+) T cell responses. The human adenovirus (Ad) serotype 5 has been tested in malaria vaccine clinical trials with excellent safety profile. Nevertheless, a major concern for the use of Ad5 is the high prevalence of anti-vector neutralizing Abs in humans, hampering its immunogenicity. To minimize the impact of anti-vector pre-existing immunity, we developed a chimeric Ad5/3 vector in which the knob region of Ad5 was replaced with that of Ad3, conferring partial resistance to anti-Ad5 neutralizing Abs. Furthermore, we implemented heterologous Ad/protein immunization regimens that include a single immunization with recombinant Ad vectors. Our data show that immunization with the recombinant Ad5/3 vector induces protective efficacy indistinguishable from that elicited by Ad5. Our study also demonstrates that the dose of the Ad vectors has an impact on the memory profile and protective efficacy. The results support further studies with Ad5/3 for malaria vaccine development.
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Affiliation(s)
- Monica Cabrera-Mora
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329
| | - Jairo Andres Fonseca
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329; Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA 30303; and
| | - Balwan Singh
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329
| | - Chunxia Zhao
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329
| | - Natalia Makarova
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329
| | - Igor Dmitriev
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63108
| | - David T Curiel
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63108
| | - Jerry Blackwell
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329; Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA 30303; and
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329; Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA 30303; and
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10
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Gu Y, Huang J, Wang X, Wang L, Yang J, Zhan B, Zhu X. Identification and characterization of CD4 + T cell epitopes present in Trichinella spiralis paramyosin. Vet Parasitol 2016; 231:59-62. [PMID: 27353726 DOI: 10.1016/j.vetpar.2016.06.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 06/12/2016] [Accepted: 06/15/2016] [Indexed: 11/25/2022]
Abstract
Trichinellosis is a worldwide zoonosis and vaccinating swine with a potent vaccine is a practical approach to prevent Trichinella infections in China. Paramyosin of T. spiralis (Ts-Pmy) was shown in our previous work to be a good vaccine candidate against Trichinella infections. Because CD4+ T cells play a crucial role in effective immunity against T. spiralis infection, identifying CD4+ T cell epitopes of paramyosin is crucial for constructing a chimeric subunit epitope vaccine. Twelve CD4+ T cell epitopes of Ts-Pmy with the highest scores were predicted and synthesized as peptides. Five of the twelve peptides, P2, P3, P4, P5 and P12, induced strong splenocyte proliferation and secretion of the Th2 cytokines IL-4 and IL-5 from rTs-Pmy-immunized mouse splenocytes. To assess the immunogenicity of CD4+ T cell epitopes in vivo, splenocytes from mice immunized with individual peptides were stimulated with the corresponding peptides. P2, P3, P4 and P5 induced strong cell proliferation and secretion of both Th1 (INF-γ, IL-2) and Th2 (IL-4, IL-5) cytokines. The results indicate that the peptides P2, P3, P4 and P5 are immunodominant CD4+ T cell epitopes of Ts-Pmy. This study will facilitate the design of an effective epitope-based multivalent subunit vaccine against Trichinella infections.
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Affiliation(s)
- Yuan Gu
- Department of Microbiology and Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, PR China
| | - Jingjing Huang
- Department of Microbiology and Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, PR China
| | - Xiaohuan Wang
- Department of Microbiology and Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, PR China
| | - Lei Wang
- Department of Microbiology and Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, PR China
| | - Jing Yang
- Department of Microbiology and Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, PR China
| | - Bin Zhan
- Department of Pediatrics, Section of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xinping Zhu
- Department of Microbiology and Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, PR China.
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11
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Fonseca JA, Cabrera-Mora M, Kashentseva EA, Villegas JP, Fernandez A, Van Pelt A, Dmitriev IP, Curiel DT, Moreno A. A Plasmodium Promiscuous T Cell Epitope Delivered within the Ad5 Hexon Protein Enhances the Protective Efficacy of a Protein Based Malaria Vaccine. PLoS One 2016; 11:e0154819. [PMID: 27128437 PMCID: PMC4851317 DOI: 10.1371/journal.pone.0154819] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/19/2016] [Indexed: 12/20/2022] Open
Abstract
A malaria vaccine is a public health priority. In order to produce an effective vaccine, a multistage approach targeting both the blood and the liver stage infection is desirable. The vaccine candidates also need to induce balanced immune responses including antibodies, CD4+ and CD8+ T cells. Protein-based subunit vaccines like RTS,S are able to induce strong antibody response but poor cellular reactivity. Adenoviral vectors have been effective inducing protective CD8+ T cell responses in several models including malaria; nonetheless this vaccine platform exhibits a limited induction of humoral immune responses. Two approaches have been used to improve the humoral immunogenicity of recombinant adenovirus vectors, the use of heterologous prime-boost regimens with recombinant proteins or the genetic modification of the hypervariable regions (HVR) of the capsid protein hexon to express B cell epitopes of interest. In this study, we describe the development of capsid modified Ad5 vectors that express a promiscuous Plasmodium yoelii T helper epitope denominated PyT53 within the hexon HVR2 region. Several regimens were tested in mice to determine the relevance of the hexon modification in enhancing protective immune responses induced by the previously described protein-based multi-stage experimental vaccine PyCMP. A heterologous prime-boost immunization regime that combines a hexon modified vector with transgenic expression of PyCMP followed by protein immunizations resulted in the induction of robust antibody and cellular immune responses in comparison to a similar regimen that includes a vector with unmodified hexon. These differences in immunogenicity translated into a better protective efficacy against both the hepatic and red blood cell stages of P. yoelii. To our knowledge, this is the first time that a hexon modification is used to deliver a promiscuous T cell epitope. Our data support the use of such modification to enhance the immunogenicity and protective efficacy of adenoviral based malaria vaccines.
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Affiliation(s)
- Jairo Andres Fonseca
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Monica Cabrera-Mora
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Elena A. Kashentseva
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - John Paul Villegas
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Alejandra Fernandez
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Amelia Van Pelt
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Igor P. Dmitriev
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - David T. Curiel
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States of America
- * E-mail:
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12
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Induction of Multifunctional Broadly Reactive T Cell Responses by a Plasmodium vivax Circumsporozoite Protein Recombinant Chimera. Infect Immun 2015; 83:3749-61. [PMID: 26169267 DOI: 10.1128/iai.00480-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/03/2015] [Indexed: 12/31/2022] Open
Abstract
Plasmodium vivax is the most widespread species of Plasmodium, causing up to 50% of the malaria cases occurring outside sub-Saharan Africa. An effective vaccine is essential for successful control and potential eradication. A well-characterized vaccine candidate is the circumsporozoite protein (CSP). Preclinical and clinical trials have shown that both antibodies and cellular immune responses have been correlated with protection induced by immunization with CSP. On the basis of our reported approach of developing chimeric Plasmodium yoelii proteins to enhance protective efficacy, we designed PvRMC-CSP, a recombinant chimeric protein based on the P. vivax CSP (PvCSP). In this engineered protein, regions of the PvCSP predicted to contain human T cell epitopes were genetically fused to an immunodominant B cell epitope derived from the N-terminal region I and to repeat sequences representing the two types of PvCSP repeats. The chimeric protein was expressed in soluble form with high yield. As the immune response to PvCSP has been reported to be genetically restricted in the murine model, we tested the immunogenicity of PvRMC-CSP in groups of six inbred strains of mice. PvRMC-CSP was able to induce robust antibody responses in all the mouse strains tested. Synthetic peptides representing the allelic forms of the P. vivax CSP were also recognized to a similar extent regardless of the mouse strain. Furthermore, the immunization regimen induced high frequencies of multifunctional CD4(+) and CD8(+) PvRMC-CSP-specific T cells. The depth and breadth of the immune responses elicited suggest that immunization with PvRMC-CSP can circumvent the genetic restriction of the immune response to P. vivax CSP. Interestingly, PvRMC-CSP was also recognized by naturally acquired antibodies from individuals living in areas where malaria is endemic. These features make PvRMC-CSP a promising vaccine candidate for further development.
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13
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Ferreira AR, Singh B, Cabrera-Mora M, Magri De Souza AC, Queiroz Marques MT, Porto LCS, Santos F, Banic DM, Calvo-Calle JM, Oliveira-Ferreira J, Moreno A, Da Costa Lima-Junior J. Evaluation of naturally acquired IgG antibodies to a chimeric and non-chimeric recombinant species of Plasmodium vivax reticulocyte binding protein-1: lack of association with HLA-DRB1*/DQB1* in malaria exposed individuals from the Brazilian Amazon. PLoS One 2014; 9:e105828. [PMID: 25148251 PMCID: PMC4141821 DOI: 10.1371/journal.pone.0105828] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 07/24/2014] [Indexed: 02/06/2023] Open
Abstract
The development of modular constructs that include antigenic regions targeted by protective immune responses is an attractive approach for subunit vaccine development. However, a main concern of using these vaccine platforms is how to preserve the antigenic identity of conformational B cell epitopes. In the present study we evaluated naturally acquired antibody responses to a chimeric protein engineered to contain a previously defined immunodominant domain of the Plasmodium vivax reticulocyte binding protein-1 located between amino acid positions K435-I777. The construct also includes three regions of the cognate protein (F571-D587, I1745-S1786 and L2235-E2263) predicted to contain MHC class II promiscuous T cell epitopes. Plasma samples from 253 naturally exposed individuals were tested against this chimeric protein named PvRMC-RBP1 and a control protein that includes the native sequence PvRBP123-751 in comparative experiments to study the frequency of total IgG and IgG subclass reactivity. HLA-DRB1 and HLA-DQB1 allelic groups were typed by PCR-SSO to evaluate the association between major HLA class II alleles and antibody responses. We found IgG antibodies that recognized the chimeric PvRMC-RBP1 and the PvRBP123-751 in 47.1% and 60% of the studied population, respectively. Moreover, the reactivity index against both proteins were comparable and associated with time of exposure (p<0.0001) and number of previous malaria episodes (p<0.005). IgG subclass profile showed a predominance of cytophilic IgG1 over other subclasses against both proteins tested. Collectively these studies suggest that the chimeric PvRMC-RBP1 protein retained antigenic determinants in the PvRBP1435–777 native sequence. Although 52.9% of the population did not present detectable titers of antibodies to PvRMC-RBP1, genetic restriction to this chimeric protein does not seem to occur, since no association was observed between the HLA-DRB1* or HLA-DQB1* alleles and the antibody responses. This experimental evidence strongly suggests that the identity of the conformational B cell epitopes is preserved in the chimeric protein.
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Affiliation(s)
- Amanda Ribeiro Ferreira
- Laboratory of Immunoparasitology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, (FIOCRUZ), Rio de Janeiro, RJ, Brazil
| | - Balwan Singh
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Monica Cabrera-Mora
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Alana Cristina Magri De Souza
- Laboratory of Immunoparasitology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, (FIOCRUZ), Rio de Janeiro, RJ, Brazil
| | | | | | - Fatima Santos
- National Health Foundation, Department of Entomology, Central Laboratory, Porto Velho, RO, Brazil
| | - Dalma Maria Banic
- Laboratory for Simuliidae and Onchocerciasis, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, (FIOCRUZ), Rio de Janeiro, RJ, Brazil
| | - J. Mauricio Calvo-Calle
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Joseli Oliveira-Ferreira
- Laboratory of Immunoparasitology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, (FIOCRUZ), Rio de Janeiro, RJ, Brazil
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Georgia, United States of America
- * E-mail: (AM); (JCLJ)
| | - Josué Da Costa Lima-Junior
- Laboratory of Immunoparasitology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, (FIOCRUZ), Rio de Janeiro, RJ, Brazil
- * E-mail: (AM); (JCLJ)
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14
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Alaro JR, Partridge A, Miura K, Diouf A, Lopez AM, Angov E, Long CA, Burns JM. A chimeric Plasmodium falciparum merozoite surface protein vaccine induces high titers of parasite growth inhibitory antibodies. Infect Immun 2013; 81:3843-54. [PMID: 23897613 PMCID: PMC3811772 DOI: 10.1128/iai.00522-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 07/23/2013] [Indexed: 01/20/2023] Open
Abstract
The C-terminal 19-kDa domain of Plasmodium falciparum merozoite surface protein 1 (PfMSP119) is an established target of protective antibodies. However, clinical trials of PfMSP142, a leading blood-stage vaccine candidate which contains the protective epitopes of PfMSP119, revealed suboptimal immunogenicity and efficacy. Based on proof-of-concept studies in the Plasmodium yoelii murine model, we produced a chimeric vaccine antigen containing recombinant PfMSP119 (rPfMSP119) fused to the N terminus of P. falciparum merozoite surface protein 8 that lacked its low-complexity Asn/Asp-rich domain, rPfMSP8 (ΔAsn/Asp). Immunization of mice with the chimeric rPfMSP1/8 vaccine elicited strong T cell responses to conserved epitopes associated with the rPfMSP8 (ΔAsn/Asp) fusion partner. While specific for PfMSP8, this T cell response was adequate to provide help for the production of high titers of antibodies to both PfMSP119 and rPfMSP8 (ΔAsn/Asp) components. This occurred with formulations adjuvanted with either Quil A or with Montanide ISA 720 plus CpG oligodeoxynucleotide (ODN) and was observed in both inbred and outbred strains of mice. PfMSP1/8-induced antibodies were highly reactive with two major alleles of PfMSP119 (FVO and 3D7). Of particular interest, immunization with PfMSP1/8 elicited higher titers of PfMSP119-specific antibodies than a combined formulation of rPfMSP142 and rPfMSP8 (ΔAsn/Asp). As a measure of functionality, PfMSP1/8-specific rabbit IgG was shown to potently inhibit the in vitro growth of blood-stage parasites of the FVO and 3D7 strains of P. falciparum. These data support the further testing and evaluation of this chimeric PfMSP1/8 antigen as a component of a multivalent vaccine for P. falciparum malaria.
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Affiliation(s)
- James R. Alaro
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Andrea Partridge
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Kazutoyo Miura
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Ababacar Diouf
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Ana M. Lopez
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Evelina Angov
- U.S. Military Malaria Research Program, Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Carole A. Long
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - James M. Burns
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
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15
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A hybrid multistage protein vaccine induces protective immunity against murine malaria. Infect Immun 2012; 80:1491-501. [PMID: 22252877 DOI: 10.1128/iai.05980-11] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We have previously reported the design and expression of chimeric recombinant proteins as an effective platform to deliver malaria vaccines. The erythrocytic and exoerythrocytic protein chimeras described included autologous T helper epitopes genetically linked to defined B cell epitopes. Proof-of-principle studies using vaccine constructs based on the Plasmodium yoelii circumsporozoite protein (CSP) and P. yoelii merozoite surface protein-1 (MSP-1) showed encouraging results when tested individually in this mouse malaria model. To evaluate the potential synergistic or additive effect of combining these chimeric antigens, we constructed a synthetic gene encoding a hybrid protein that combined both polypeptides in a single immunogen. The multistage vaccine was expressed in soluble form in Escherichia coli at high yield. Here we report that the multistage protein induced robust immune responses to individual components, with no evidence of vaccine interference. Passive immunization using purified IgG from rabbits immunized with the hybrid protein conferred more robust protection against the experimental challenge with P. yoelii sporozoites than passive immunization with purified IgG from rabbits immunized with the individual proteins. High antibody titers and high frequencies of CD4(+)- and CD8(+)-specific cytokine-secreting T cells were elicited by vaccination. T cells were multifunctional and able to simultaneously produce interleukin-2 (IL-2), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α). The mechanism of vaccine-induced protection involved neutralizing antibodies and effector CD4(+) T cells and resulted in the control of hyperparasitemia and protection against malarial anemia. These data support our strategy of using an array of autologous T helper epitopes to maximize the response to multistage malaria vaccines.
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16
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Malaria Vaccine Development: Are Bacterial Flagellin Fusion Proteins the Bridge between Mouse and Humans? J Parasitol Res 2011; 2011:965369. [PMID: 21603205 PMCID: PMC3095412 DOI: 10.1155/2011/965369] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 01/18/2011] [Indexed: 12/25/2022] Open
Abstract
In the past 25 years, the development of an effective malaria vaccine has become one of the biggest riddles in the biomedical sciences. Experimental data using animal infection models demonstrated that it is possible to induce protective immunity against different stages of malaria parasites. Nonetheless, the vast body of knowledge has generated disappointments when submitted to clinical conditions and presently a single antigen formulation has progressed to the point where it may be translated into a human vaccine. In parallel, new means to increase the protective effects of antigens in general have been pursued and depicted, such as the use of bacterial flagellins as carriers/adjuvants. Flagellins activate pathways in the innate immune system of both mice and humans. The recent report of the first Phase I clinical trial of a vaccine containing a Salmonella flagellin as carrier/adjuvant may fuel the use of these proteins in vaccine formulations. Herein, we review the studies on the use of recombinant flagellins as vaccine adjuvants with malarial antigens in the light of the current state of the art of malaria vaccine development. The available information indicates that bacterial flagellins should be seriously considered for malaria vaccine formulations to the development of effective human vaccines.
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