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Takashima E, Otsuki H, Morita M, Ito D, Nagaoka H, Yuguchi T, Hassan I, Tsuboi T. The Need for Novel Asexual Blood-Stage Malaria Vaccine Candidates for Plasmodium falciparum. Biomolecules 2024; 14:100. [PMID: 38254700 PMCID: PMC10813614 DOI: 10.3390/biom14010100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/25/2023] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Extensive control efforts have significantly reduced malaria cases and deaths over the past two decades, but in recent years, coupled with the COVID-19 pandemic, success has stalled. The WHO has urged the implementation of a number of interventions, including vaccines. The modestly effective RTS,S/AS01 pre-erythrocytic vaccine has been recommended by the WHO for use in sub-Saharan Africa against Plasmodium falciparum in children residing in moderate to high malaria transmission regions. A second pre-erythrocytic vaccine, R21/Matrix-M, was also recommended by the WHO on 3 October 2023. However, the paucity and limitations of pre-erythrocytic vaccines highlight the need for asexual blood-stage malaria vaccines that prevent disease caused by blood-stage parasites. Few asexual blood-stage vaccine candidates have reached phase 2 clinical development, and the challenges in terms of their efficacy include antigen polymorphisms and low immunogenicity in humans. This review summarizes the history and progress of asexual blood-stage malaria vaccine development, highlighting the need for novel candidate vaccine antigens/molecules.
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Affiliation(s)
- Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Hitoshi Otsuki
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan; (H.O.); (D.I.)
| | - Masayuki Morita
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Daisuke Ito
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan; (H.O.); (D.I.)
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Takaaki Yuguchi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Ifra Hassan
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan; (M.M.); (H.N.); (T.Y.); (I.H.)
| | - Takafumi Tsuboi
- Division of Cell-Free Sciences, Proteo-Science Center, Ehime University, Matsuyama 790-8577, Japan
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Tiono AB, Palacpac NMQ, Bougouma EC, Nebie I, Ouédraogo A, Houard S, Arisue N, D’Alessio F, Horii T, Sirima SB. Plasmodium falciparum infection coinciding with the malaria vaccine candidate BK-SE36 administration interferes with the immune responses in Burkinabe children. Front Immunol 2023; 14:1119820. [PMID: 36993981 PMCID: PMC10040972 DOI: 10.3389/fimmu.2023.1119820] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/21/2023] [Indexed: 03/14/2023] Open
Abstract
BackgroundA vaccine targeting the erythrocyte stages of Plasmodium falciparum could play a role in preventing clinical disease. BK-SE36 is a promising malaria vaccine candidate that has shown a good safety profile and immunological responses during field evaluations. It was observed that repeated natural infections could result in immune tolerance against SE36 molecule.MethodsThe primary trial was conducted to assess the safety and immunogenicity of the BK-SE36 in two cohorts of children aged 25-60 months (Cohort 1) and 12-24 months (Cohort 2). Immunization was at full dose (1.0 mL) administered at 0, 1, and 6 months. Blood samples were collected before each vaccination for immunological assessments and detection of Plasmodium falciparum infection by microscopy. Blood samples were further collected one month post each vaccination to evaluate immunogenicity.ResultsOf seventy-two (72) subjects that have received BK-SE36 vaccination, 71 had available blood smears during vaccination days. One month post Dose 2, the geometric mean of SE36 antibodies was 263.2 (95% CI: 178.9-387.1) in uninfected individuals compared to 77.1 (95% CI: 47.3-125.7) in infected participants. The same trend was observed one-month post booster dose. Participants uninfected at the time of booster vaccination had significantly higher GMTs compared to those who were infected (424.1 (95% CI: 301.9-595.8) vs. 92.8 (95% CI: 34.9-246.6), p = 0.002. There was a 14.3 (95% CI: 9.7-21.1) and 2.4 (95% CI: 1.3-4.4) fold-change, respectively, in uninfected and infected participants between one-month post Dose 2 and booster. The difference was statistically significant (p < 0.001).ConclusionConcomitant infection by P. falciparum during BK-SE36 vaccine candidate administration is associated with reduced humoral responses. However, it is to be noted that the BK-SE36 primary trial was not designed to investigate the influence of concomitant infection on vaccine-induced immune response and should be interpreted cautiously.Trial registrationWHO ICTRP, PACTR201411000934120.
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Affiliation(s)
- Alfred B. Tiono
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Nirianne Marie Q. Palacpac
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | | | - Issa Nebie
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
| | - Alphonse Ouédraogo
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
| | - Sophie Houard
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Nobuko Arisue
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Flavia D’Alessio
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- *Correspondence: Toshihiro Horii, ; Sodiomon B. Sirima,
| | - Sodiomon B. Sirima
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
- *Correspondence: Toshihiro Horii, ; Sodiomon B. Sirima,
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Arisue N, Palacpac NMQ, Ntege EH, Yeka A, Balikagala B, Kanoi BN, Bougouma EC, Tiono AB, Nebie I, Diarra A, Houard S, D’Alessio F, Leroy O, Sirima SB, Egwang TG, Horii T. African-specific polymorphisms in Plasmodium falciparum serine repeat antigen 5 in Uganda and Burkina Faso clinical samples do not interfere with antibody response to BK-SE36 vaccination. Front Cell Infect Microbiol 2022; 12:1058081. [PMID: 36590593 PMCID: PMC9802637 DOI: 10.3389/fcimb.2022.1058081] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022] Open
Abstract
BK-SE36, based on Plasmodium falciparum serine repeat antigen 5 (SERA5), is a blood-stage malaria vaccine candidate currently being evaluated in clinical trials. Phase 1 trials in Uganda and Burkina Faso have demonstrated promising safety and immunogenicity profiles. However, the genetic diversity of sera5 in Africa and the role of allele/variant-specific immunity remain a major concern. Here, sequence analyses were done on 226 strains collected from the two clinical trial/follow-up studies and 88 strains from two cross-sectional studies in Africa. Compared to other highly polymorphic vaccine candidate antigens, polymorphisms in sera5 were largely confined to the repeat regions of the gene. Results also confirmed a SERA5 consensus sequence with African-specific polymorphisms. Mismatches with the vaccine-type SE36 (BK-SE36) in the octamer repeat, serine repeat, and flanking regions, and single-nucleotide polymorphisms in non-repeat regions could compromise vaccine response and efficacy. However, the haplotype diversity of SERA5 was similar between vaccinated and control participants. There was no marked bias or difference in the patterns of distribution of the SE36 haplotype and no statistically significant genetic differentiation among parasites infecting BK-SE36 vaccinees and controls. Results indicate that BK-SE36 does not elicit an allele-specific immune response.
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Affiliation(s)
- Nobuko Arisue
- Research Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan,Section of Global Health, Division of Public Health, Department of Hygiene and Public Health, Tokyo Women’s Medical University, Tokyo, Japan,*Correspondence: Nobuko Arisue, ; Nirianne Marie Q. Palacpac,
| | - Nirianne Marie Q. Palacpac
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan,*Correspondence: Nobuko Arisue, ; Nirianne Marie Q. Palacpac,
| | - Edward H. Ntege
- Department of Plastic and Reconstructive Surgery, University of the Ryukyus, Graduate School of Medicine and Hospital, Okinawa, Japan
| | - Adoke Yeka
- Makerere University School of Public Health, Kampala, Uganda
| | - Betty Balikagala
- Department of Tropical Medicine and Parasitology, School of Medicine, Juntendo University, Tokyo, Japan
| | - Bernard N. Kanoi
- Centre for Malaria Elimination (CME) and Centre for Research in Infectious Diseases (CRID), Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
| | - Edith Christiane Bougouma
- Public Health Department, Institut National de Santé Publique/Centre National de Recherche et de Formation sur le Paludisme (INSP/CNRFP), Ouagadougou, Burkina Faso,Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Alfred B. Tiono
- Public Health Department, Institut National de Santé Publique/Centre National de Recherche et de Formation sur le Paludisme (INSP/CNRFP), Ouagadougou, Burkina Faso,Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Issa Nebie
- Public Health Department, Institut National de Santé Publique/Centre National de Recherche et de Formation sur le Paludisme (INSP/CNRFP), Ouagadougou, Burkina Faso,Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Amidou Diarra
- Public Health Department, Institut National de Santé Publique/Centre National de Recherche et de Formation sur le Paludisme (INSP/CNRFP), Ouagadougou, Burkina Faso,Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | - Sophie Houard
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Flavia D’Alessio
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Odile Leroy
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany,Sorekara-x consultant, Paris, France
| | - Sodiomon B. Sirima
- Public Health Department, Institut National de Santé Publique/Centre National de Recherche et de Formation sur le Paludisme (INSP/CNRFP), Ouagadougou, Burkina Faso,Groupe de Recherche Action en Santé (GRAS), Ouagadougou, Burkina Faso
| | | | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
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Computational Clues of Immunogenic Hotspots in Plasmodium falciparum Erythrocytic Stage Vaccine Candidate Antigens: In Silico Approach. BIOMED RESEARCH INTERNATIONAL 2022; 2022:5886687. [PMID: 36277884 PMCID: PMC9584662 DOI: 10.1155/2022/5886687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 09/27/2022] [Indexed: 11/30/2022]
Abstract
Malaria is the most pernicious parasitic infection, and Plasmodium falciparum is the most virulent species with substantial morbidity and mortality worldwide. The present in silico investigation was performed to reveal the biophysical characteristics and immunogenic epitopes of the 14 blood-stage proteins of the P. falciparum using comprehensive immunoinformatics approaches. For this aim, various web servers were employed to predict subcellular localization, antigenicity, allergenicity, solubility, physicochemical properties, posttranslational modification sites (PTMs), the presence of signal peptide, and transmembrane domains. Moreover, structural analysis for secondary and 3D model predictions were performed for all and stable proteins, respectively. Finally, human helper T lymphocyte (HTL) epitopes were predicted using HLA reference set of IEDB server and screened in terms of antigenicity, allergenicity, and IFN-γ induction as well as population coverage. Also, a multiserver B-cell epitope prediction was done with subsequent screening for antigenicity, allergenicity, and solubility. Altogether, these proteins showed appropriate antigenicity, abundant PTMs, and many B-cell and HTL epitopes, which could be directed for future vaccination studies in the context of multiepitope vaccine design.
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Bougouma EC, Palacpac NMQ, Tiono AB, Nebie I, Ouédraogo A, Houard S, Yagi M, Coulibaly SA, Diarra A, Tougan T, Ouedraogo AZ, Soulama I, Arisue N, Yaro JB, D’Alessio F, Leroy O, Cousens S, Horii T, Sirima SB. Safety and immunogenicity of BK-SE36 in a blinded, randomized, controlled, age de-escalating phase Ib clinical trial in Burkinabe children. Front Immunol 2022; 13:978591. [PMID: 36119062 PMCID: PMC9471861 DOI: 10.3389/fimmu.2022.978591] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Background A blood-stage vaccine targeting the erythrocytic-stages of the malaria parasite Plasmodium falciparum could play a role to protect against clinical disease. Antibodies against the P. falciparum serine repeat antigen 5 (SE47 and SE36 domains) correlate well with the absence of clinical symptoms in sero-epidemiological studies. A previous phase Ib trial of the recombinant SE36 antigen formulated with aluminum hydroxyl gel (BK-SE36) was promising. This is the first time the vaccine candidate was evaluated in young children below 5 years using two vaccination routes. Methods Safety and immunogenicity of BK-SE36 was assessed in a double-blind, randomized, controlled, age de-escalating phase Ib trial. Fifty-four Burkinabe children in each age cohort, 25–60 or 12–24 months, were randomized in a 1:1:1 ratio to receive three doses of BK-SE36 either by intramuscular (BK IM) or subcutaneous (BK SC) route on Day 0, Week 4, and 26; or the control vaccine, Synflorix®via IM route on Day 0, Week 26 (and physiological saline on Week 4). Safety data and samples for immunogenicity analyses were collected at various time-points. Results Of 108 subjects, 104 subjects (96.3%) (Cohort 1: 94.4%; Cohort 2: 98.1%) received all three scheduled vaccine doses. Local reactions, mostly mild or of moderate severity, occurred in 99 subjects (91.7%). The proportion of subjects that received three doses without experiencing Grade 3 adverse events was similar across BK-SE36 vaccines and control arms (Cohort 1: 100%, 89%, and 89%; and Cohort 2: 83%, 82%, and 83% for BK IM, BK SC, and control, respectively). BK-SE36 vaccine was immunogenic, inducing more than 2-fold change in antibody titers from pre-vaccination, with no difference between the two vaccination routes. Titers waned before the third dose but in both cohorts titers were boosted 6 months after the first vaccination. The younger cohort had 2-fold and 4-fold higher geometric mean titers compared to the 25- to 60-month-old cohort after 2 and 3 doses of BK-SE36, respectively. Conclusion BK-SE36 was well tolerated and immunogenic using either intramuscular or subcutaneous routes, with higher immune response in the younger cohort. Clinical Trial Registration https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=934, identifier PACTR201411000934120.
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Affiliation(s)
- Edith Christiane Bougouma
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Nirianne Marie Q. Palacpac
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Alfred B. Tiono
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Issa Nebie
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Alphonse Ouédraogo
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Sophie Houard
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Masanori Yagi
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Sam Aboubacar Coulibaly
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Amidou Diarra
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Takahiro Tougan
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Amidou Z. Ouedraogo
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Issiaka Soulama
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Nobuko Arisue
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Jean Baptiste Yaro
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
| | - Flavia D’Alessio
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Odile Leroy
- European Vaccine Initiative (EVI), Universitäts Klinikum Heidelberg, Heidelberg, Germany
| | - Simon Cousens
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom
| | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
- *Correspondence: Toshihiro Horii, ; Sodiomon B. Sirima,
| | - Sodiomon B. Sirima
- Groupe de Recherche Action en Santé, Ouagadougou (GRAS), Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme (CNRFP), Ouagadougou, Burkina Faso
- *Correspondence: Toshihiro Horii, ; Sodiomon B. Sirima,
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Abugri J, Ayariga J, Sunwiale SS, Wezena CA, Gyamfi JA, Adu-Frimpong M, Agongo G, Dongdem JT, Abugri D, Dinko B. Targeting the Plasmodium falciparum proteome and organelles for potential antimalarial drug candidates. Heliyon 2022; 8:e10390. [PMID: 36033316 PMCID: PMC9398786 DOI: 10.1016/j.heliyon.2022.e10390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 01/12/2022] [Accepted: 08/15/2022] [Indexed: 11/28/2022] Open
Abstract
There is an unmet need to unearth alternative treatment options for malaria, wherein this quest is more pressing in recent times due to high morbidity and mortality data arising mostly from the endemic countries coupled with partial diversion of attention from the disease in view of the SARS-Cov-2 pandemic. Available therapeutic options for malaria have been severely threatened with the emergence of resistance to almost all the antimalarial drugs by the Plasmodium falciparum parasite in humans, which is a worrying situation. Artemisinin combination therapies (ACT) that have so far been the mainstay of malaria have encountered resistance by malaria parasite in South East Asia, which is regarded as a notorious ground zero for the emergence of resistance to antimalarial drugs. This review analyzes a few key druggable targets for the parasite and the potential of specific inhibitors to mitigate the emerging antimalarial drug resistance problem by providing a concise assessment of the essential proteins of the malaria parasite that could serve as targets. Moreover, this work provides a summary of the advances made in malaria parasite biology and the potential to leverage these findings for antimalarial drug production.
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Affiliation(s)
- James Abugri
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Joseph Ayariga
- The Biomedical Engineering Programme, Alabama State University, Montgomery, AL, 36104, USA
| | - Samuel Sunyazi Sunwiale
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Cletus Adiyaga Wezena
- Department of Microbiology, School of Biosciences, University for Development Studies (UDS), Nyankpala Campus, Tamale, Ghana
| | - Julien Agyemang Gyamfi
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Michael Adu-Frimpong
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Godfred Agongo
- Department of Biochemistry and Forensic Sciences, School of Chemical and Biochemical Sciences, C. K. Tedam University of Technology and Applied Sciences (CKT-UTAS), Navrongo, Ghana
| | - Julius Tieroyaare Dongdem
- Department of Biochemistry and Molecular Medicine. School of Medicine. University for Development Studies (UDS), Tamale-Campus, Ghana
| | - Daniel Abugri
- Department of Biological Sciences, Microbiology PhD Programme, Laboratory of Ethnomedicine, Parasitology, and Drug Discovery, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, USA
| | - Bismarck Dinko
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho. Ghana
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Goodswen SJ, Kennedy PJ, Ellis JT. Compilation of parasitic immunogenic proteins from 30 years of published research using machine learning and natural language processing. Sci Rep 2022; 12:10349. [PMID: 35725870 PMCID: PMC9208253 DOI: 10.1038/s41598-022-13790-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 05/18/2022] [Indexed: 12/02/2022] Open
Abstract
The World Health Organisation reported in 2020 that six of the top 10 sources of death in low-income countries are parasites. Parasites are microorganisms in a relationship with a larger organism, the host. They acquire all benefits at the host’s expense. A disease develops if the parasitic infection disrupts normal functioning of the host. This disruption can range from mild to severe, including death. Humans and livestock continue to be challenged by established and emerging infectious disease threats. Vaccination is the most efficient tool for preventing current and future threats. Immunogenic proteins sourced from the disease-causing parasite are worthwhile vaccine components (subunits) due to reliable safety and manufacturing capacity. Publications with ‘subunit vaccine’ in their title have accumulated to thousands over the last three decades. However, there are possibly thousands more reporting immunogenicity results without mentioning ‘subunit’ and/or ‘vaccine’. The exact number is unclear given the non-standardised keywords in publications. The study aim is to identify parasite proteins that induce a protective response in an animal model as reported in the scientific literature within the last 30 years using machine learning and natural language processing. Source code to fulfil this aim and the vaccine candidate list obtained is made available.
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Affiliation(s)
- Stephen J Goodswen
- School of Life Sciences, University of Technology Sydney, 15 Broadway, Ultimo, NSW, 2007, Australia
| | - Paul J Kennedy
- School of Computer Science, Faculty of Engineering and Information Technology and the Australian Artificial Intelligence Institute, University of Technology Sydney, 15 Broadway, Ultimo, NSW, 2007, Australia
| | - John T Ellis
- School of Life Sciences, University of Technology Sydney, 15 Broadway, Ultimo, NSW, 2007, Australia.
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Vekemans J, Schellenberg D, Benns S, O'Brien K, Alonso P. Meeting report: WHO consultation on malaria vaccine development, Geneva, 15-16 July 2019. Vaccine 2021; 39:2907-2916. [PMID: 33931251 DOI: 10.1016/j.vaccine.2021.03.093] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 01/25/2023]
Abstract
Considerable progress has been made in malaria control in the last two decades, but progress has stalled in the last few years. New tools are needed to achieve public health goals in malaria control and elimination. A first generation vaccine, RTS,S/AS01, is currently being evaluated as it undergoes pilot implementation through routine health systems in parts of three African countries. The development of this vaccine took over 30 years and has been full of uncertainties. Even now, important unknowns remain as to its future role in public health. Lessons need to be learnt for second generation and future vaccines, including how to facilitate early planning of investments, streamlining of development, regulatory and policy pathways. A number of candidate vaccines populate the current development pipeline, some of which have the potential to contribute to burden reduction if efficacy is confirmed in conditions of natural exposure, and if they are amenable to affordable supply and programmatic implementation. New, innovative technologies will be needed if future malaria vaccines are to overcome important scientific hurdles and induce durable, high level protection. WHO convened a stakeholder consultation on the status of malaria vaccine research and development to inform the recently reconstituted Malaria Vaccine Advisory Committee (MALVAC) which will assist WHO in updating its current guidance and recommendations about priorities and product preferences for malaria vaccines.
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Affiliation(s)
- Johan Vekemans
- World Health Organization, 20 Av Appia, 1211 Geneva 27, Switzerland
| | | | | | - Kate O'Brien
- World Health Organization, 20 Av Appia, 1211 Geneva 27, Switzerland
| | - Pedro Alonso
- World Health Organization, 20 Av Appia, 1211 Geneva 27, Switzerland
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Arisue N, Chagaluka G, Palacpac NMQ, Johnston WT, Mutalima N, Peprah S, Bhatia K, Borgstein E, Liomba GN, Kamiza S, Mkandawire N, Mitambo C, Goedert JJ, Molyneux EM, Newton R, Horii T, Mbulaiteye SM. Assessment of Mixed Plasmodium falciparum sera5 Infection in Endemic Burkitt Lymphoma: A Case-Control Study in Malawi. Cancers (Basel) 2021; 13:1692. [PMID: 33918470 PMCID: PMC8038222 DOI: 10.3390/cancers13071692] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Endemic Burkitt lymphoma (eBL) is the most common childhood cancer in Africa and is linked to Plasmodium falciparum (Pf) malaria infection, one of the most common and deadly childhood infections in Africa; however, the role of Pf genetic diversity is unclear. A potential role of Pf genetic diversity in eBL has been suggested by a correlation of age-specific patterns of eBL with the complexity of Pf infection in Ghana, Uganda, and Tanzania, as well as a finding of significantly higher Pf genetic diversity, based on a sensitive molecular barcode assay, in eBL cases than matched controls in Malawi. We examined this hypothesis by measuring diversity in Pf-serine repeat antigen-5 (Pfsera5), an antigenic target of blood-stage immunity to malaria, among 200 eBL cases and 140 controls, all Pf polymerase chain reaction (PCR)-positive, in Malawi. METHODS We performed Pfsera5 PCR and sequencing (~3.3 kb over exons II-IV) to determine single or mixed PfSERA5 infection status. The patterns of Pfsera5 PCR positivity, mixed infection, sequence variants, and haplotypes among eBL cases, controls, and combined/pooled were analyzed using frequency tables. The association of mixed Pfsera5 infection with eBL was evaluated using logistic regression, controlling for age, sex, and previously measured Pf genetic diversity. RESULTS Pfsera5 PCR was positive in 108 eBL cases and 70 controls. Mixed PfSERA5 infection was detected in 41.7% of eBL cases versus 24.3% of controls; the odds ratio (OR) was 2.18, and the 95% confidence interval (CI) was 1.12-4.26, which remained significant in adjusted results (adjusted odds ratio [aOR] of 2.40, 95% CI of 1.11-5.17). A total of 29 nucleotide variations and 96 haplotypes were identified, but these were unrelated to eBL. CONCLUSIONS Our results increase the evidence supporting the hypothesis that infection with mixed Pf infection is increased with eBL and suggest that measuring Pf genetic diversity may provide new insights into the role of Pf infection in eBL.
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Affiliation(s)
- Nobuko Arisue
- Research Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan;
| | - George Chagaluka
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Private Bag 360, Chichiri, Blantyre 3, Malawi; (G.C.); (E.B.); (G.N.L.); (S.K.); (N.M.); (E.M.M.)
| | - Nirianne Marie Q. Palacpac
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; (N.M.Q.P.); (T.H.)
| | - W. Thomas Johnston
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York YO10 5DD, UK; (W.T.J.); (N.M.); (R.N.)
| | - Nora Mutalima
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York YO10 5DD, UK; (W.T.J.); (N.M.); (R.N.)
- Cancer Epidemiology Unit, University of Oxford, Oxford OX3 7LF, UK
| | - Sally Peprah
- Infections and Immunoepidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.P.); (K.B.); (J.J.G.)
| | - Kishor Bhatia
- Infections and Immunoepidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.P.); (K.B.); (J.J.G.)
| | - Eric Borgstein
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Private Bag 360, Chichiri, Blantyre 3, Malawi; (G.C.); (E.B.); (G.N.L.); (S.K.); (N.M.); (E.M.M.)
| | - George N. Liomba
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Private Bag 360, Chichiri, Blantyre 3, Malawi; (G.C.); (E.B.); (G.N.L.); (S.K.); (N.M.); (E.M.M.)
| | - Steve Kamiza
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Private Bag 360, Chichiri, Blantyre 3, Malawi; (G.C.); (E.B.); (G.N.L.); (S.K.); (N.M.); (E.M.M.)
| | - Nyengo Mkandawire
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Private Bag 360, Chichiri, Blantyre 3, Malawi; (G.C.); (E.B.); (G.N.L.); (S.K.); (N.M.); (E.M.M.)
| | - Collins Mitambo
- National Health Sciences Research Committee, Research Department, Ministry of Health, P.O. Box 30377, Capital City, Lilongwe 3, Malawi;
| | - James J. Goedert
- Infections and Immunoepidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.P.); (K.B.); (J.J.G.)
| | - Elizabeth M. Molyneux
- Departments of Pediatrics and Surgery, College of Medicine, University of Malawi, Private Bag 360, Chichiri, Blantyre 3, Malawi; (G.C.); (E.B.); (G.N.L.); (S.K.); (N.M.); (E.M.M.)
| | - Robert Newton
- Epidemiology and Cancer Statistics Group, Department of Health Sciences, University of York, York YO10 5DD, UK; (W.T.J.); (N.M.); (R.N.)
| | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; (N.M.Q.P.); (T.H.)
| | - Sam M. Mbulaiteye
- Infections and Immunoepidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.P.); (K.B.); (J.J.G.)
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10
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Arisue N, Palacpac NMQ, Tougan T, Horii T. Characteristic features of the SERA multigene family in the malaria parasite. Parasit Vectors 2020; 13:170. [PMID: 32252804 PMCID: PMC7132891 DOI: 10.1186/s13071-020-04044-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/27/2020] [Indexed: 02/28/2023] Open
Abstract
Serine repeat antigen (SERA) is conserved among species of the genus Plasmodium. Sera genes form a multigene family and are generally tandemly clustered on a single chromosome. Although all Plasmodium species encode multiple sera genes, the number varies between species. Among species, the members share similar sequences and gene organization. SERA possess a central papain-like cysteine protease domain, however, in some members, the active site cysteine residue is substituted with a serine. Recent studies implicate this gene family in a number of aspects in parasite biology and induction of protective immune response. This review summarizes the current understanding on this important gene family in several Plasmodium species. The Plasmodium falciparum (Pf)-sera family, for example, consists of nine gene members. Unlike other multigene families in Plasmodium species, Pf-sera genes do not exhibit antigenic variation. Pf-sera5 nucleotide diversity is also low. Moreover, although Pf-sera5 is highly transcribed during the blood stage of malaria infection, and a large amount is released into the host blood following schizont rupture, in malaria endemic countries the sero-positive rates for Pf-SERA5 are low, likely due to Pf-SERA5 binding of host proteins to avoid immune recognition. As an antigen, the N-terminal 47 kDa domain of Pf-SERA5 is a promising vaccine candidate currently undergoing clinical trials. Pf-SERA5 and Pf-SERA6, as well as P. berghei (Pb)-SERA3, and Pb-SERA5, have been investigated for their roles in parasite egress. Two P. yoelii SERA, which have a serine residue at the protease active center, are implicated in parasite virulence. Overall, these studies provide insight that during the evolution of the Plasmodium parasite, the sera gene family members have increased by gene duplication, and acquired various functions that enable the parasite to survive and successfully maintain infection in the host.![]()
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Affiliation(s)
- Nobuko Arisue
- Research Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, 565-0871, Japan.
| | - Nirianne M Q Palacpac
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Takahiro Tougan
- Research Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, 565-0871, Japan
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11
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Salamanca DR, Gómez M, Camargo A, Cuy-Chaparro L, Molina-Franky J, Reyes C, Patarroyo MA, Patarroyo ME. Plasmodium falciparum Blood Stage Antimalarial Vaccines: An Analysis of Ongoing Clinical Trials and New Perspectives Related to Synthetic Vaccines. Front Microbiol 2019; 10:2712. [PMID: 31849871 PMCID: PMC6901501 DOI: 10.3389/fmicb.2019.02712] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/08/2019] [Indexed: 01/10/2023] Open
Abstract
Plasmodium falciparum malaria is a disease causing high morbidity and mortality rates worldwide, mainly in sub-Saharan Africa. Candidates have been identified for vaccines targeting the parasite's blood stage; this stage is important in the development of symptoms and clinical complications. However, no vaccine that can directly affect morbidity and mortality rates is currently available. This review analyzes the formulation, methodological design, and results of active clinical trials for merozoite-stage vaccines, regarding their safety profile, immunological response (phase Ia/Ib), and protective efficacy levels (phase II). Most vaccine candidates are in phase I trials and have had an acceptable safety profile. GMZ2 has made the greatest progress in clinical trials; its efficacy has been 14% in children aged less than 5 years in a phase IIb trial. Most of the available candidates that have shown strong immunogenicity and that have been tested for their protective efficacy have provided good results when challenged with a homologous parasite strain; however, their efficacy has dropped when they have been exposed to a heterologous strain. In view of these vaccines' unpromising results, an alternative approach for selecting new candidates is needed; such line of work should be focused on how to increase an immune response induced against the highly conserved (i.e., common to all strains), functionally relevant, protein regions that the parasite uses to invade target cells. Despite binding regions tending to be conserved, they are usually poorly antigenic and/or immunogenic, being frequently discarded as vaccine candidates when the conventional immunological approach is followed. The Fundación Instituto de Inmunología de Colombia (FIDIC) has developed a logical and rational methodology based on including conserved high-activity binding peptides (cHABPs) from the main P. falciparum biologically functional proteins involved in red blood cell (RBC) invasion. Once appropriately modified (mHABPs), these minimal, subunit-based, chemically synthesized peptides can be used in a system covering the human immune system's main genetic variables (the human leukocyte antigen HLA-DR isotype) inducing a suitable, immunogenic, and protective immune response in most of the world's populations.
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Affiliation(s)
- David Ricardo Salamanca
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Marcela Gómez
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Anny Camargo
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Laura Cuy-Chaparro
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Jessica Molina-Franky
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - César Reyes
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Manuel Alfonso Patarroyo
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Manuel Elkin Patarroyo
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Department of Pathology, School of Medicine, Universidad Nacional de Colombia, Boyacá, Colombia
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12
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Iyer GR, Singh S, Kaur I, Agarwal S, Siddiqui MA, Bansal A, Kumar G, Saini E, Paul G, Mohmmed A, Chitnis CE, Malhotra P. Calcium-dependent phosphorylation of Plasmodium falciparum serine repeat antigen 5 triggers merozoite egress. J Biol Chem 2018; 293:9736-9746. [PMID: 29716996 DOI: 10.1074/jbc.ra117.001540] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/13/2018] [Indexed: 01/13/2023] Open
Abstract
The human malaria parasite Plasmodium falciparum proliferates in red blood cells following repeated cycles of invasion, multiplication, and egress. P. falciparum serine repeat antigen 5 (PfSERA5), a putative serine protease, plays an important role in merozoite egress. However, regulation of its activity leading to merozoite egress is poorly understood. In this study, we show that PfSERA5 undergoes phosphorylation prior to merozoite egress. Immunoprecipitation of parasite lysates using anti-PfSERA5 serum followed by MS analysis identified calcium-dependent protein kinase 1 (PfCDPK1) as an interacting kinase. Association of PfSERA5 with PfCDPK1 was corroborated by co-sedimentation, co-immunoprecipitation, and co-immunolocalization analyses. Interestingly, PfCDPK1 phosphorylated PfSERA5 in vitro in the presence of Ca2+ and enhanced its proteolytic activity. A PfCDPK1 inhibitor, purfalcamine, blocked the phosphorylation and activation of PfSERA5 both in vitroas well as in schizonts, which, in turn, blocked merozoite egress. Together, these results suggest that phosphorylation of PfSERA5 by PfCDPK1 following a rise in cytosolic Ca2+ levels activates its proteolytic activity to trigger merozoite egress.
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Affiliation(s)
- Gayatri R Iyer
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Shailja Singh
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and.,the Department of Parasites and Insect Vectors, Institut Pasteur, 25-28 rue du Doctor Roux, 75015 Paris, France
| | - Inderjeet Kaur
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Shalini Agarwal
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Mansoor A Siddiqui
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Abhisheka Bansal
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Gautam Kumar
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Ekta Saini
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Gourab Paul
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Asif Mohmmed
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
| | - Chetan E Chitnis
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and .,the Department of Parasites and Insect Vectors, Institut Pasteur, 25-28 rue du Doctor Roux, 75015 Paris, France
| | - Pawan Malhotra
- From the Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India and
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13
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Molecular Camouflage of Plasmodium falciparum Merozoites by Binding of Host Vitronectin to P47 Fragment of SERA5. Sci Rep 2018; 8:5052. [PMID: 29567995 PMCID: PMC5864917 DOI: 10.1038/s41598-018-23194-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/07/2018] [Indexed: 12/31/2022] Open
Abstract
The malaria parasite Plasmodium falciparum proliferates in the blood stream where the host immune system is most active. To escape from host immunity, P. falciparum has developed a number of evasion mechanisms. Serine repeat antigen 5 (SERA5) is a blood stage antigen highly expressed at late trophozoite and schizont stages. The P47 N-terminal domain of SERA5, the basis of SE36 antigen of the blood stage vaccine candidate under clinical trials, covers the merozoite surface. Exploring the role of the P47 domain, screening of serum proteins showed that vitronectin (VTN) directly binds to 20 residues in the C-terminal region of SE36. VTN co-localized with P47 domain in the schizont and merozoite stages. Phagocytosis assay using THP-1 cells demonstrated that VTN bound to SE36 prevented engulfment of SE36-beads. In addition, several serum proteins localized on the merozoite surface, suggesting that host proteins camouflage merozoites against host immunity via binding to VTN.
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14
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Stabilization of a chimeric malaria antigen in separation and purification through efficient inhibition of protease activity by imidazole. Process Biochem 2018. [DOI: 10.1016/j.procbio.2017.10.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Ntege EH, Takashima E, Morita M, Nagaoka H, Ishino T, Tsuboi T. Blood-stage malaria vaccines: post-genome strategies for the identification of novel vaccine candidates. Expert Rev Vaccines 2017; 16:769-779. [PMID: 28604122 DOI: 10.1080/14760584.2017.1341317] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION An efficacious malaria vaccine is necessary to advance the current control measures towards malaria elimination. To-date, only RTS,S/AS01, a leading pre-erythrocytic stage vaccine completed phase 3 trials, but with an efficacy of 28-36% in children, and 18-26% in infants, that waned over time. Blood-stage malaria vaccines protect against disease, and are considered effective targets for the logical design of next generation vaccines to improve the RTS,S field efficacy. Therefore, novel blood-stage vaccine candidate discovery efforts are critical, albeit with several challenges including, high polymorphisms in vaccine antigens, poor understanding of targets of naturally protective immunity, and difficulties in the expression of high AT-rich plasmodial proteins. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects of malaria vaccine research and development. We focused on post-genome vaccine candidate discovery, malaria vaccine development, sequence diversity, pre-clinical and clinical trials. Expert commentary: Post-genome high-throughput technologies using wheat germ cell-free protein synthesis technology and immuno-profiling with sera from malaria patients with clearly defined outcomes are highlighted to overcome current challenges of malaria vaccine candidate discovery.
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Affiliation(s)
- Edward H Ntege
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Eizo Takashima
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Masayuki Morita
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Hikaru Nagaoka
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Tomoko Ishino
- b Division of Molecular Parasitology , Proteo-Science Center, Ehime University , Toon , Ehime , Japan
| | - Takafumi Tsuboi
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
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16
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Lempereur L, Larcombe SD, Durrani Z, Karagenc T, Bilgic HB, Bakirci S, Hacilarlioglu S, Kinnaird J, Thompson J, Weir W, Shiels B. Identification of candidate transmission-blocking antigen genes in Theileria annulata and related vector-borne apicomplexan parasites. BMC Genomics 2017; 18:438. [PMID: 28583072 PMCID: PMC5460460 DOI: 10.1186/s12864-017-3788-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/11/2017] [Indexed: 01/11/2023] Open
Abstract
Background Vector-borne apicomplexan parasites are a major cause of mortality and morbidity to humans and livestock globally. The most important disease syndromes caused by these parasites are malaria, babesiosis and theileriosis. Strategies for control often target parasite stages in the mammalian host that cause disease, but this can result in reservoir infections that promote pathogen transmission and generate economic loss. Optimal control strategies should protect against clinical disease, block transmission and be applicable across related genera of parasites. We have used bioinformatics and transcriptomics to screen for transmission-blocking candidate antigens in the tick-borne apicomplexan parasite, Theileria annulata. Results A number of candidate antigen genes were identified which encoded amino acid domains that are conserved across vector-borne Apicomplexa (Babesia, Plasmodium and Theileria), including the Pfs48/45 6-cys domain and a novel cysteine-rich domain. Expression profiling confirmed that selected candidate genes are expressed by life cycle stages within infected ticks. Additionally, putative B cell epitopes were identified in the T. annulata gene sequences encoding the 6-cys and cysteine rich domains, in a gene encoding a putative papain-family cysteine peptidase, with similarity to the Plasmodium SERA family, and the gene encoding the T. annulata major merozoite/piroplasm surface antigen, Tams1. Conclusions Candidate genes were identified that encode proteins with similarity to known transmission blocking candidates in related parasites, while one is a novel candidate conserved across vector-borne apicomplexans and has a potential role in the sexual phase of the life cycle. The results indicate that a ‘One Health’ approach could be utilised to develop a transmission-blocking strategy effective against vector-borne apicomplexan parasites of animals and humans. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3788-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Laetitia Lempereur
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow, G61 1QH, Scotland, UK.,Present address: Laboratory of Parasitology and Parasitic Diseases, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium
| | - Stephen D Larcombe
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow, G61 1QH, Scotland, UK
| | - Zeeshan Durrani
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow, G61 1QH, Scotland, UK.,Present address: School of Veterinary Science, University of Liverpool, Chester High Road, Neston, CH64 7TE,, UK
| | - Tulin Karagenc
- Faculty of Veterinary Medicine, Department of Parasitology, Adnan Menderes University, Batı Kampus, Işıklı, Aydın, Turkey
| | - Huseyin Bilgin Bilgic
- Faculty of Veterinary Medicine, Department of Parasitology, Adnan Menderes University, Batı Kampus, Işıklı, Aydın, Turkey
| | - Serkan Bakirci
- Faculty of Veterinary Medicine, Department of Parasitology, Adnan Menderes University, Batı Kampus, Işıklı, Aydın, Turkey
| | - Selin Hacilarlioglu
- Faculty of Veterinary Medicine, Department of Parasitology, Adnan Menderes University, Batı Kampus, Işıklı, Aydın, Turkey
| | - Jane Kinnaird
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow, G61 1QH, Scotland, UK
| | - Joanne Thompson
- Institute of Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FL, UK
| | - William Weir
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow, G61 1QH, Scotland, UK
| | - Brian Shiels
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow, G61 1QH, Scotland, UK.
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17
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Paojinda P, Imprasittichai W, Krungkrai SR, Palacpac NMQ, Horii T, Krungkrai J. Bifunctional activity of fused Plasmodium falciparum orotate phosphoribosyltransferase and orotidine 5'-monophosphate decarboxylase. Parasitol Int 2017; 67:79-84. [PMID: 28389349 DOI: 10.1016/j.parint.2017.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 03/31/2017] [Accepted: 04/03/2017] [Indexed: 10/19/2022]
Abstract
Fusion of the last two enzymes in the pyrimidine biosynthetic pathway in the inversed order by having a COOH-terminal orotate phosphoribosyltransferase (OPRT) and an NH2-terminal orotidine 5'-monophosphate decarboxylase (OMPDC), as OMPDC-OPRT, are described in many organisms. Here, we produced gene fusions of Plasmodium falciparum OMPDC-OPRT and expressed the bifunctional protein in Escherichia coli. The enzyme was purified to homogeneity using affinity and anion-exchange chromatography, exhibited enzymatic activities and functioned as a dimer. The activities, although unstable, were stabilized by its substrate and product during purification and long-term storage. Furthermore, the enzyme expressed a perfect catalytic efficiency (kcat/Km). The kcat was selectively enhanced up to three orders of magnitude, while the Km was not much affected and remained at low μM levels when compared to the monofunctional enzymes. The fusion of the two enzymes, creating a "super-enzyme" with perfect catalytic power and more flexibility, reflects cryptic relationship of enzymatic reactivities and metabolic functions on molecular evolution.
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Affiliation(s)
- Patsarawadee Paojinda
- Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; Inter-Department Program of Biomedical Science, Faculty of Graduate School, Chulalongkorn University, Bangkok 10330, Thailand
| | - Waranya Imprasittichai
- Department of Basic Medical Science, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, Bangkok 10300, Thailand
| | - Sudaratana R Krungkrai
- Unit of Biochemistry, Department of Medical Science, Faculty of Science, Rangsit University, Patumthani 12000, Thailand
| | - Nirianne Marie Q Palacpac
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Jerapan Krungkrai
- Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
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Yagi M, Palacpac NMQ, Ito K, Oishi Y, Itagaki S, Balikagala B, Ntege EH, Yeka A, Kanoi BN, Katuro O, Shirai H, Fukushima W, Hirota Y, Egwang TG, Horii T. Antibody titres and boosting after natural malaria infection in BK-SE36 vaccine responders during a follow-up study in Uganda. Sci Rep 2016; 6:34363. [PMID: 27703240 PMCID: PMC5050508 DOI: 10.1038/srep34363] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 09/09/2016] [Indexed: 11/12/2022] Open
Abstract
The malaria vaccine BK-SE36 is a recombinant protein (SE36) based on the Honduras 1 serine repeat antigen-5 of Plasmodium falciparum, adsorbed to aluminium hydroxide gel. The phase Ib trial in Uganda demonstrated the safety and immunogenicity of BK-SE36. Ancillary analysis in the follow-up study of 6–20 year-old volunteers suggest significant differences in time to first episodes of clinical malaria in vaccinees compared to placebo/control group. Here, we aimed to get further insights into the association of anti-SE36 antibody titres and natural P. falciparum infection. Children who received BK-SE36 and whose antibody titres against SE36 increased by ≥1.92-fold after vaccination were categorised as responders. Most responders did not have or only had a single episode of natural P. falciparum infection. Notably, responders who did not experience infection had relatively high anti-SE36 antibody titres post-second vaccination compared to those who were infected. The anti-SE36 antibody titres of the responders who experienced malaria were boosted after infection and they had lower risk of reinfection. These findings show that anti-SE36 antibody titres induced by BK-SE36 vaccination offered protection against malaria. The vaccine is now being evaluated in a phase Ib trial in children less than 5 years old.
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Affiliation(s)
- Masanori Yagi
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Nirianne M Q Palacpac
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Kazuya Ito
- Department of Public Health, Faculty of Medicine, Osaka City University, Osaka 545-8585, Japan.,Sumida Hospital, Medical Co. Living Together Association (LTA) Clinical Pharmacology Center, Tokyo 130-0021 Japan
| | - Yuko Oishi
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Sawako Itagaki
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Betty Balikagala
- Med Biotech Laboratories, Plot 4-6 Bell Close, Port Bell Road Luzira, Kampala, Uganda
| | - Edward H Ntege
- Med Biotech Laboratories, Plot 4-6 Bell Close, Port Bell Road Luzira, Kampala, Uganda
| | - Adoke Yeka
- Med Biotech Laboratories, Plot 4-6 Bell Close, Port Bell Road Luzira, Kampala, Uganda.,Department of Disease Control and Environmental Health, School of Public Health, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
| | - Bernard N Kanoi
- Med Biotech Laboratories, Plot 4-6 Bell Close, Port Bell Road Luzira, Kampala, Uganda
| | - Osbert Katuro
- Med Biotech Laboratories, Plot 4-6 Bell Close, Port Bell Road Luzira, Kampala, Uganda
| | - Hiroki Shirai
- The Research Foundation for Microbial Diseases of Osaka University, 2-9-41 Yahata-cho, Kanonji, Kagawa 768-0061 Japan
| | - Wakaba Fukushima
- Department of Public Health, Faculty of Medicine, Osaka City University, Osaka 545-8585, Japan
| | - Yoshio Hirota
- Department of Public Health, Faculty of Medicine, Osaka City University, Osaka 545-8585, Japan
| | - Thomas G Egwang
- Med Biotech Laboratories, Plot 4-6 Bell Close, Port Bell Road Luzira, Kampala, Uganda
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871 Japan
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19
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Lee MSJ, Igari Y, Tsukui T, Ishii KJ, Coban C. Current status of synthetic hemozoin adjuvant: A preliminary safety evaluation. Vaccine 2016; 34:2055-61. [DOI: 10.1016/j.vaccine.2016.02.064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 02/09/2016] [Accepted: 02/24/2016] [Indexed: 12/21/2022]
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Abstract
Although it is more than a decade since the parasite genome information was obtained, standardized novel genome-wide selection/prioritization strategies for candidacy of malaria vaccine antigens are still sought. In the quest to systematically identify candidates, it is impossible to overemphasize the usefulness of wheat germ cell-free technology in expressing quality proteins for the post-genome vaccine candidate discovery.
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Affiliation(s)
- Eizo Takashima
- a Division of Malaria Research, Proteo-Science Center , Ehime University , Matsuyama , Ehime 790-8577 , Japan
| | - Masayuki Morita
- a Division of Malaria Research, Proteo-Science Center , Ehime University , Matsuyama , Ehime 790-8577 , Japan
| | - Takafumi Tsuboi
- a Division of Malaria Research, Proteo-Science Center , Ehime University , Matsuyama , Ehime 790-8577 , Japan
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21
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Draper SJ, Angov E, Horii T, Miller LH, Srinivasan P, Theisen M, Biswas S. Recent advances in recombinant protein-based malaria vaccines. Vaccine 2015; 33:7433-43. [PMID: 26458807 PMCID: PMC4687528 DOI: 10.1016/j.vaccine.2015.09.093] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 09/05/2015] [Accepted: 09/28/2015] [Indexed: 01/03/2023]
Abstract
Protein-based vaccines remain the cornerstone approach for B cell and antibody induction against leading target malaria antigens. Advances in antigen selection, immunogen design and epitope-focusing are advancing the field. New heterologous expression platforms are enabling cGMP production of next-generation protein vaccines. Next-generation antigens, protein-based immunogens and virus-like particle (VLP) delivery platforms are in clinical development. Protein-based vaccines will form part of a highly effective multi-component/multi-stage/multi-antigen subunit formulation against malaria.
Plasmodium parasites are the causative agent of human malaria, and the development of a highly effective vaccine against infection, disease and transmission remains a key priority. It is widely established that multiple stages of the parasite's complex lifecycle within the human host and mosquito vector are susceptible to vaccine-induced antibodies. The mainstay approach to antibody induction by subunit vaccination has been the delivery of protein antigen formulated in adjuvant. Extensive efforts have been made in this endeavor with respect to malaria vaccine development, especially with regard to target antigen discovery, protein expression platforms, adjuvant testing, and development of soluble and virus-like particle (VLP) delivery platforms. The breadth of approaches to protein-based vaccines is continuing to expand as innovative new concepts in next-generation subunit design are explored, with the prospects for the development of a highly effective multi-component/multi-stage/multi-antigen formulation seeming ever more likely. This review will focus on recent progress in protein vaccine design, development and/or clinical testing for a number of leading malaria antigens from the sporozoite-, merozoite- and sexual-stages of the parasite's lifecycle–including PfCelTOS, PfMSP1, PfAMA1, PfRH5, PfSERA5, PfGLURP, PfMSP3, Pfs48/45 and Pfs25. Future prospects and challenges for the development, production, human delivery and assessment of protein-based malaria vaccines are discussed.
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Affiliation(s)
- Simon J Draper
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK.
| | - Evelina Angov
- Walter Reed Army Institute of Research, U. S. Military Malaria Research Program, Malaria Vaccine Branch, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 561-873, Japan
| | - Louis H Miller
- Malaria Cell Biology Section, Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Prakash Srinivasan
- Malaria Cell Biology Section, Laboratory of Malaria and Vector Research, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark; Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology and Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Sumi Biswas
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, UK
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Abstract
The development of a highly effective malaria vaccine remains a key goal to aid in the control and eventual eradication of this devastating parasitic disease. The field has made huge strides in recent years, with the first-generation vaccine RTS,S showing modest efficacy in a Phase III clinical trial. The updated 2030 Malaria Vaccine Technology Roadmap calls for a second generation vaccine to achieve 75% efficacy over two years for both Plasmodium falciparum and Plasmodium vivax, and for a vaccine that can prevent malaria transmission. Whole-parasite immunisation approaches and combinations of pre-erythrocytic subunit vaccines are now reporting high-level efficacy, whilst exciting new approaches to the development of blood-stage and transmission-blocking vaccine subunit components are entering clinical development. The development of a highly effective multi-component multi-stage subunit vaccine now appears to be a realistic ambition. This review will cover these recent developments in malaria vaccinology.
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23
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Finney OC, Danziger SA, Molina DM, Vignali M, Takagi A, Ji M, Stanisic DI, Siba PM, Liang X, Aitchison JD, Mueller I, Gardner MJ, Wang R. Predicting antidisease immunity using proteome arrays and sera from children naturally exposed to malaria. Mol Cell Proteomics 2014; 13:2646-60. [PMID: 25023128 DOI: 10.1074/mcp.m113.036632] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Malaria remains one of the most prevalent and lethal human infectious diseases worldwide. A comprehensive characterization of antibody responses to blood stage malaria is essential to support the development of future vaccines, sero-diagnostic tests, and sero-surveillance methods. We constructed a proteome array containing 4441 recombinant proteins expressed by the blood stages of the two most common human malaria parasites, P. falciparum (Pf) and P. vivax (Pv), and used this array to screen sera of Papua New Guinea children infected with Pf, Pv, or both (Pf/Pv) that were either symptomatic (febrile), or asymptomatic but had parasitemia detectable via microscopy or PCR. We hypothesized that asymptomatic children would develop antigen-specific antibody profiles associated with antidisease immunity, as compared with symptomatic children. The sera from these children recognized hundreds of the arrayed recombinant Pf and Pv proteins. In general, responses in asymptomatic children were highest in those with high parasitemia, suggesting that antibody levels are associated with parasite burden. In contrast, symptomatic children carried fewer antibodies than asymptomatic children with infections detectable by microscopy, particularly in Pv and Pf/Pv groups, suggesting that antibody production may be impaired during symptomatic infections. We used machine-learning algorithms to investigate the relationship between antibody responses and symptoms, and we identified antibody responses to sets of Plasmodium proteins that could predict clinical status of the donors. Several of these antibody responses were identified by multiple comparisons, including those against members of the serine enriched repeat antigen family and merozoite protein 4. Interestingly, both P. falciparum serine enriched repeat antigen-5 and merozoite protein 4 have been previously investigated for use in vaccines. This machine learning approach, never previously applied to proteome arrays, can be used to generate a list of potential seroprotective and/or diagnostic antigens candidates that can be further evaluated in longitudinal studies.
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Affiliation(s)
- Olivia C Finney
- From the ‡Seattle Biomedical Research Institute, 307 Westlake Ave N., Suite 500, Seattle, WA 98109 USA
| | - Samuel A Danziger
- From the ‡Seattle Biomedical Research Institute, 307 Westlake Ave N., Suite 500, Seattle, WA 98109 USA; §Institute for Systems Biology, 401 Terry Ave N, Seattle, WA 98109 USA
| | - Douglas M Molina
- ¶Antigen Discovery Inc. (ADi), 1 Technology Dr E, Irvine, CA 92618 USA
| | - Marissa Vignali
- From the ‡Seattle Biomedical Research Institute, 307 Westlake Ave N., Suite 500, Seattle, WA 98109 USA
| | - Aki Takagi
- From the ‡Seattle Biomedical Research Institute, 307 Westlake Ave N., Suite 500, Seattle, WA 98109 USA
| | - Ming Ji
- ‖Division of Epidemiology/Biostatistics, Graduate School of Public Health, San Diego State University, Hardy Tower 119, 5500 Campanile Drive, San Diego, CA 92182
| | - Danielle I Stanisic
- **Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea; ‡‡Walter & Eliza Hall Institute, 1G Royal Parade, Parkville Victoria 3052, Australia
| | - Peter M Siba
- **Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Xiawu Liang
- ¶Antigen Discovery Inc. (ADi), 1 Technology Dr E, Irvine, CA 92618 USA
| | - John D Aitchison
- From the ‡Seattle Biomedical Research Institute, 307 Westlake Ave N., Suite 500, Seattle, WA 98109 USA; §Institute for Systems Biology, 401 Terry Ave N, Seattle, WA 98109 USA
| | - Ivo Mueller
- **Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea; ‡‡Walter & Eliza Hall Institute, 1G Royal Parade, Parkville Victoria 3052, Australia; §§Barcelona Centre for International Health Research, Carrer Roselló 132, 08036 Barcelona, Spain
| | - Malcolm J Gardner
- From the ‡Seattle Biomedical Research Institute, 307 Westlake Ave N., Suite 500, Seattle, WA 98109 USA
| | - Ruobing Wang
- From the ‡Seattle Biomedical Research Institute, 307 Westlake Ave N., Suite 500, Seattle, WA 98109 USA;
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24
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Protective epitopes of the Plasmodium falciparum SERA5 malaria vaccine reside in intrinsically unstructured N-terminal repetitive sequences. PLoS One 2014; 9:e98460. [PMID: 24886718 PMCID: PMC4041889 DOI: 10.1371/journal.pone.0098460] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 05/04/2014] [Indexed: 01/27/2023] Open
Abstract
The malaria vaccine candidate antigen, SE36, is based on the N-terminal 47 kDa domain of Plasmodium falciparum serine repeat antigen 5 (SERA5). In epidemiological studies, we have previously shown the inhibitory effects of SE36 specific antibodies on in vitro parasite growth and the negative correlation between antibody level and malaria symptoms. A phase 1 b trial of the BK-SE36 vaccine in Uganda elicited 72% protective efficacy against symptomatic malaria in children aged 6–20 years during the follow-up period 130–365 days post–second vaccination. Here, we performed epitope mapping with synthetic peptides covering the whole sequence of SE36 to identify and map dominant epitopes in Ugandan adult serum presumed to have clinical immunity to P. falciparum malaria. High titer sera from the Ugandan adults predominantly reacted with peptides corresponding to two successive N-terminal regions of SERA5 containing octamer repeats and serine rich sequences, regions of SERA5 that were previously reported to have limited polymorphism. Affinity purified antibodies specifically recognizing the octamer repeats and serine rich sequences exhibited a high antibody-dependent cellular inhibition (ADCI) activity that inhibited parasite growth. Furthermore, protein structure predictions and structural analysis of SE36 using spectroscopic methods indicated that N-terminal regions possessing inhibitory epitopes are intrinsically unstructured. Collectively, these results suggest that strict tertiary structure of SE36 epitopes is not required to elicit protective antibodies in naturally immune Ugandan adults.
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25
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Kanodia S, Kumar G, Rizzi L, Pedretti A, Hodder AN, Romeo S, Malhotra P. Synthetic peptides derived from the C-terminal 6kDa region of Plasmodium falciparum SERA5 inhibit the enzyme activity and malaria parasite development. Biochim Biophys Acta Gen Subj 2014; 1840:2765-75. [PMID: 24769454 DOI: 10.1016/j.bbagen.2014.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 03/21/2014] [Accepted: 04/15/2014] [Indexed: 11/27/2022]
Abstract
BACKGROUND Plasmodium falciparum serine repeat antigen 5 (PfSERA5) is an abundant blood stage protein that plays an essential role in merozoite egress and invasion. The native protein undergoes extensive proteolytic cleavage that appears to be tightly regulated. PfSERA5 N-terminal fragment is being developed as vaccine candidate antigen. Although PfSERA5 belongs to papain-like cysteine protease family, its catalytic domain has a serine in place of cysteine at the active site. METHODS In the present study, we synthesized a number of peptides from the N- and C-terminal regions of PfSERA5 active domain and evaluated their inhibitory potential. RESULTS The final proteolytic step of PfSERA5 involves removal of a C-terminal ~6kDa fragment that results in the generation of a catalytically active ~50kDa enzyme. In the present study, we demonstrate that two of the peptides derived from the C-terminal ~6kDa region inhibit the parasite growth and also cause a delay in the parasite development. These peptides reduced the enzyme activity of the recombinant protein and co-localized with the PfSERA5 protein within the parasite, thereby indicating the specific inhibition of PfSERA5 activity. Molecular docking studies revealed that the inhibitory peptides interact with the active site of the protein. Interestingly, the peptides did not have an effect on the processing of PfSERA5. CONCLUSIONS Our observations indicate the temporal regulation of the final proteolytic cleavage step that occurs just prior to egress. GENERAL SIGNIFICANCE These results reinforce the role of PfSERA5 for the intra-erythrocytic development of malaria parasite and show the role of carboxy terminal ~6kDa fragments in the regulation of PfSERA5 activity. The results also suggest that final cleavage step of PfSERA5 can be targeted for the development of new anti-malarials.
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Affiliation(s)
- Shivani Kanodia
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Gautam Kumar
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Luca Rizzi
- Dipartimento di Scienze Farmaceutiche, Facoltà di Scienze del Farmaco, Università degli Studi di Milano, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Alessandro Pedretti
- Dipartimento di Scienze Farmaceutiche, Facoltà di Scienze del Farmaco, Università degli Studi di Milano, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Anthony N Hodder
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia
| | - Sergio Romeo
- Dipartimento di Scienze Farmaceutiche, Facoltà di Scienze del Farmaco, Università degli Studi di Milano, Via L. Mangiagalli 25, 20133 Milan, Italy
| | - Pawan Malhotra
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
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Tougan T, J. Ishii K, Horii T. Development and Application of Next Generation SE36 Malaria Vaccine Formulated with a Novel Adjuvant: Approach to Travelers' Vaccine. YAKUGAKU ZASSHI 2013; 133:1153-7. [DOI: 10.1248/yakushi.13-00212-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Takahiro Tougan
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University
| | - Ken J. Ishii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University
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27
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Aka P, Vila MC, Jariwala A, Nkrumah F, Emmanuel B, Yagi M, Palacpac NMQ, Periago MV, Neequaye J, Kiruthu C, Tougan T, Levine PH, Biggar RJ, Pfeiffer RM, Bhatia K, Horii T, Bethony JM, Mbulaiteye SM. Endemic Burkitt lymphoma is associated with strength and diversity of Plasmodium falciparum malaria stage-specific antigen antibody response. Blood 2013; 122:629-35. [PMID: 23645841 PMCID: PMC3731925 DOI: 10.1182/blood-2012-12-475665] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 04/25/2013] [Indexed: 11/20/2022] Open
Abstract
Endemic Burkitt lymphoma (eBL) is linked to Plasmodium falciparum (Pf) infection geographically, but evidence from individual-level studies is limited. We investigated this issue among 354 childhood eBL cases and 384 age-, sex-, and location-matched controls enrolled in Ghana from 1965 to 1994. Immunoglobulin G1 (IgG1) and immunoglobulin G3 (IgG3) antibodies to antigens diagnostic of recent infection Pf histidine-rich protein-II (HRP-II) and 6NANP, Pf-vaccine candidates SE36 and 42-kDa region of the 3D7 Pf merozoite surface protein-1 (MSP-1), and tetanus toxoid were measured by indirect enzyme-linked immunoassay. Odds ratios (ORs) and 95% confidence intervals (CIs) for association with eBL were estimated using unconditional logistic regression. After adjustments, eBL was positively associated with HRP-IIIgG3 seropositivity (adjusted OR: 1.60; 95% CI 1.08-2.36) and inversely associated with SE36IgG1 seropositivity (adjusted OR: 0.37; 95% CI 0.21-0.64) and with tetanus toxoidIgG3 levels equal or higher than the mean (adjusted OR: 0.46; 95% CI 0.32-0.66). Anti-MSP-1IgG3 and anti-6NANPIgG3 were indeterminate. eBL risk was potentially 21 times higher (95% CI 5.8-74) in HRP-IIIgG3-seropositive and SE36IgG1-seronegative responders compared with HRP-IIIgG3-seronegative and SE36IgG1-seropositive responders. Our results suggest that recent malaria may be associated with risk of eBL but long-term infection may be protective.
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Affiliation(s)
- Peter Aka
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20892, USA
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28
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Association of naturally acquired IgG antibodies against Plasmodium falciparum serine repeat antigen-5 with reduced placental parasitemia and normal birth weight in pregnant Ugandan women: A pilot study. Parasitol Int 2013; 62:237-9. [DOI: 10.1016/j.parint.2013.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 01/10/2013] [Accepted: 01/30/2013] [Indexed: 01/06/2023]
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29
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Palacpac NMQ, Ntege E, Yeka A, Balikagala B, Suzuki N, Shirai H, Yagi M, Ito K, Fukushima W, Hirota Y, Nsereko C, Okada T, Kanoi BN, Tetsutani K, Arisue N, Itagaki S, Tougan T, Ishii KJ, Ueda S, Egwang TG, Horii T. Phase 1b randomized trial and follow-up study in Uganda of the blood-stage malaria vaccine candidate BK-SE36. PLoS One 2013; 8:e64073. [PMID: 23724021 PMCID: PMC3665850 DOI: 10.1371/journal.pone.0064073] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 04/05/2013] [Indexed: 01/31/2023] Open
Abstract
Background Up to now a malaria vaccine remains elusive. The Plasmodium falciparum serine repeat antigen-5 formulated with aluminum hydroxyl gel (BK-SE36) is a blood-stage malaria vaccine candidate that has undergone phase 1a trial in malaria-naive Japanese adults. We have now assessed the safety and immunogenicity of BK-SE36 in a malaria endemic area in Northern Uganda. Methods We performed a two-stage, randomized, single-blinded, placebo-controlled phase 1b trial (Current Controlled trials ISRCTN71619711). A computer-generated sequence randomized healthy subjects for 2 subcutaneous injections at 21-day intervals in Stage1 (21–40 year-olds) to 1-mL BK-SE36 (BKSE1.0) (n = 36) or saline (n = 20) and in Stage2 (6–20 year-olds) to BKSE1.0 (n = 33), 0.5-mL BK-SE36 (BKSE0.5) (n = 33), or saline (n = 18). Subjects and laboratory personnel were blinded. Safety and antibody responses 21-days post-second vaccination (Day42) were assessed. Post-trial, to compare the risk of malaria episodes 130–365 days post-second vaccination, Stage2 subjects were age-matched to 50 control individuals. Results Nearly all subjects who received BK-SE36 had induration (Stage1, n = 33, 92%; Stage2, n = 63, 96%) as a local adverse event. No serious adverse event related to BK-SE36 was reported. Pre-existing anti-SE36 antibody titers negatively correlated with vaccination-induced antibody response. At Day42, change in antibody titers was significant for seronegative adults (1.95-fold higher than baseline [95% CI, 1.56–2.43], p = 0.004) and 6–10 year-olds (5.71-fold [95% CI, 2.38–13.72], p = 0.002) vaccinated with BKSE1.0. Immunogenicity response to BKSE0.5 was low and not significant (1.55-fold [95% CI, 1.24–1.94], p = 0.75). In the ancillary analysis, cumulative incidence of first malaria episodes with ≥5000 parasites/µL was 7 cases/33 subjects in BKSE1.0 and 10 cases/33 subjects in BKSE0.5 vs. 29 cases/66 subjects in the control group. Risk ratio for BKSE1.0 was 0.48 (95% CI, 0.24–0.98; p = 0.04). Conclusion BK-SE36 is safe and immunogenic. The promising potential of BK-SE36, observed in the follow-up study, warrants a double-blind phase 1/2b trial in children under 5 years. Trial Registration Controlled-Trials.com ISRCTN71619711 ISRCTN71619711
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Affiliation(s)
- Nirianne Marie Q. Palacpac
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- The Research Foundation for Microbial Diseases of Osaka University, Suita, Osaka, Japan
| | | | - Adoke Yeka
- Med Biotech Laboratories, Kampala, Uganda
- Makerere University School of Public Health, Kampala, Uganda
| | | | - Nahoko Suzuki
- The Research Foundation for Microbial Diseases of Osaka University, Kanonji, Kagawa, Japan
| | - Hiroki Shirai
- The Research Foundation for Microbial Diseases of Osaka University, Kanonji, Kagawa, Japan
| | - Masanori Yagi
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Kazuya Ito
- Department of Public Health, Faculty of Medicine, Osaka City University, Osaka, Japan
- Sumida Hospital, Medical Co. Living Together Association (LTA) Clinical Pharmacology Center, Tokyo, Japan
| | - Wakaba Fukushima
- Department of Public Health, Faculty of Medicine, Osaka City University, Osaka, Japan
| | - Yoshio Hirota
- Department of Public Health, Faculty of Medicine, Osaka City University, Osaka, Japan
| | | | - Takuya Okada
- The Research Foundation for Microbial Diseases of Osaka University, Kanonji, Kagawa, Japan
| | | | - Kohhei Tetsutani
- The Research Foundation for Microbial Diseases of Osaka University, Suita, Osaka, Japan
- Laboratory of Adjuvant Innovation, National Institute of Biomedical Innovation, Ibaraki City, Osaka, Japan
| | - Nobuko Arisue
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Sawako Itagaki
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Takahiro Tougan
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Ken J. Ishii
- Laboratory of Adjuvant Innovation, National Institute of Biomedical Innovation, Ibaraki City, Osaka, Japan
- Laboratory of Vaccine Science, Immunology Frontier Research Center, World Premier Institute for Immunology, Osaka University, Suita, Osaka, Japan
| | - Shigeharu Ueda
- The Research Foundation for Microbial Diseases of Osaka University, Suita, Osaka, Japan
| | | | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- * E-mail:
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Tougan T, Aoshi T, Coban C, Katakai Y, Kai C, Yasutomi Y, Ishii KJ, Horii T. TLR9 adjuvants enhance immunogenicity and protective efficacy of the SE36/AHG malaria vaccine in nonhuman primate models. Hum Vaccin Immunother 2013; 9:283-90. [PMID: 23291928 DOI: 10.4161/hv.22950] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The SE36 antigen, derived from serine repeat antigen 5 (SERA5) of Plasmodium falciparum, is a promising blood stage malaria vaccine candidate. Ongoing clinical trials suggest the efficacy of the SE36 vaccine could be increased by the incorporation of more effective adjuvants into the vaccine formulation. In this study, we assessed the safety, immunogenicity and protective efficacy of SE36/AHG formulated with TLR9 ligand adjuvants K3 CpG oligodeoxyribonucleotides (CpG ODNs) (K3 ODN), D3 ODN or synthetic hemozoin, in two non-human primate models. SE36/AHG with or without each adjuvant was administrated to cynomolgus monkeys. A combination of TLR9 ligand adjuvant with SE36/AHG induced higher humoral and cellular immune response compared with SE36/AHG alone. Administration of a crude extract of P. falciparum parasite resulted in the induction of more SE36-specific IgG antibodies in monkeys vaccinated with a combination of SE36/AHG and adjuvant, as opposed to vaccination with SE36/AHG alone. The most effective TLR9 ligand, K3 ODN, was chosen for further vaccine trials in squirrel monkeys, in combination with SE36/AHG. All monkeys immunized with the combined SE36/AHG and K3 ODN formulation effectively suppressed parasitemia and symptoms of malaria following challenge infections. Furthermore, no serious adverse events were observed. Our results show that the novel vaccine formulation of K3 ODN with SE36/AHG demonstrates safety, potent immunogenicity and efficacy in nonhuman primates, and this vaccine formulation may form the basis of a more effective malaria vaccine.
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Affiliation(s)
- Takahiro Tougan
- Department of Molecular Protozoology; Research Institute for Microbial Diseases; Osaka University at Suita; Osaka, Japan
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31
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Pluschke G, Tamborrini M. Development of a virosomal malaria vaccine candidate: from synthetic peptide design to clinical concept validation. Future Virol 2012. [DOI: 10.2217/fvl.12.74] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An ideal malaria vaccine would prevent disease and reduce transmission by targeting several developmental stages of human malaria parasites. To be cost-effective, a modular antigen delivery technology is required for the development of such a multivalent subunit vaccine. In this review, we summarize and discuss a strategy to develop synthetic peptidomimetics of key malaria target antigens for inclusion in a multivalent malaria subunit vaccine based on immunopotentiating reconstituted influenza virosomes. Clinical testing of a bivalent virosomal formulation incorporating two structurally optimized peptidomimetics has demonstrated safety, immunogenicity and pilot efficacy. While this clinical validation supports the concept of using peptide-loaded virosomes for vaccination in humans, it is assumed that additional antigens will have to be added to the bivalent formulation to generate a highly effective malaria vaccine.
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Affiliation(s)
- Gerd Pluschke
- Swiss Tropical & Public Health Institute, Socinstr. 57, 4002 Basel, Switzerland
| | - Marco Tamborrini
- Swiss Tropical & Public Health Institute, Socinstr. 57, 4002 Basel, Switzerland
- University of Basel, Petersplatz 1, 4003 Basel, Switzerland
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32
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Tanabe K, Arisue N, Palacpac NMQ, Yagi M, Tougan T, Honma H, Ferreira MU, Färnert A, Björkman A, Kaneko A, Nakamura M, Hirayama K, Mita T, Horii T. Geographic differentiation of polymorphism in the Plasmodium falciparum malaria vaccine candidate gene SERA5. Vaccine 2012; 30:1583-93. [PMID: 22230587 DOI: 10.1016/j.vaccine.2011.12.124] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 12/20/2011] [Accepted: 12/23/2011] [Indexed: 11/26/2022]
Abstract
SERA5 is regarded as a promising malaria vaccine candidate of the most virulent human malaria parasite Plasmodium falciparum. SERA5 is a 120 kDa abundantly expressed blood-stage protein containing a papain-like protease. Since substantial polymorphism in blood-stage vaccine candidates may potentially limit their efficacy, it is imperative to fully investigate polymorphism of the SERA5 gene (sera5). In this study, we performed evolutionary and population genetic analysis of sera5. The level of inter-species divergence (kS=0.076) between P. falciparum and Plasmodium reichenowi, a closely related chimpanzee malaria parasite is comparable to that of housekeeping protein genes. A signature of purifying selection was detected in the proenzyme and enzyme domains. Analysis of 445 near full-length P. falciparum sera5 sequences from nine countries in Africa, Southeast Asia, Oceania and South America revealed extensive variations in the number of octamer repeat (OR) and serine repeat (SR) regions as well as substantial level of single nucleotide polymorphism (SNP) in non-repeat regions (2562 bp). Remarkably, a 14 amino acid sequence of SERA5 (amino acids 59-72) that is known to be the in vitro target of parasite growth inhibitory antibodies was found to be perfectly conserved in all 445 worldwide isolates of P. falciparum evaluated. Unlike other major vaccine target antigen genes such as merozoite surface protein-1, apical membrane antigen-1 or circumsporozoite protein, no strong evidence for positive selection was detected for SNPs in the non-repeat regions of sera5. A biased geographical distribution was observed in SNPs as well as in the haplotypes of the sera5 OR and SR regions. In Africa, OR- and SR-haplotypes with low frequency (<5%) and SNPs with minor allele frequency (<5%) were abundant and were mostly continent-specific. Consistently, significant genetic differentiation, assessed by the Wright's fixation index (Fst) of inter-population variance in allele frequencies, was detected for SNPs and both OR- and SR-haplotypes among almost all parasite populations. The exception was parasite populations between Tanzania and Ghana, suggesting frequent gene flow in Africa. The present study points to the importance of investigating whether biased geographical distribution for SNPs and repeat variants in the OR and SR regions affect the reactivity of human serum antibodies to variants.
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Affiliation(s)
- Kazuyuki Tanabe
- Laboratory of Malariology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan.
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Yildiz Zeyrek F, Palacpac N, Yuksel F, Yagi M, Honjo K, Fujita Y, Arisue N, Takeo S, Tanabe K, Horii T, Tsuboi T, Ishii KJ, Coban C. Serologic markers in relation to parasite exposure history help to estimate transmission dynamics of Plasmodium vivax. PLoS One 2011; 6:e28126. [PMID: 22140521 PMCID: PMC3226671 DOI: 10.1371/journal.pone.0028126] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 11/01/2011] [Indexed: 11/18/2022] Open
Abstract
Plasmodium vivax infection has been gaining attention because of its re-emergence in several parts of the world. Southeastern Turkey is one of the places in which persistent focal malaria caused exclusively by P. vivax parasites occurs. Although control and elimination studies have been underway for many years, no detailed study has been conducted to understand the mechanisms underlying the ineffective control of malaria in this region. Here, for the first time, using serologic markers we try to extract as much information as possible in this region to get a glimpse of P. vivax transmission. We conducted a sero-immunological study, evaluating antibody responses of individuals living in Sanliurfa to four different P. vivax antigens; three blood-stage antigens (PvMSP1₁₉, PvAMA1-ecto, and PvSERA4) and one pre-erythrocytic stage antigen (PvCSP). The results suggest that a prior history of malaria infection and age can be determining factors for the levels and sustainability of naturally acquired antibodies. Significantly higher antibody responses to all the studied antigens were observed in blood smear-negative individuals with a prior history of malaria infection. Moreover, these individuals were significantly older than blood smear-negative individuals with no prior history of infection. These data from an area of sole P. vivax-endemic region may have important implications for the global malaria control/elimination programs and vaccine design.
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Affiliation(s)
- Fadile Yildiz Zeyrek
- Laboratory of Malaria Immunology, Immunology Frontier Research Center, Osaka University, Osaka, Japan
- Department of Microbiology, Harran University School of Medicine, Sanliurfa, Turkey
| | - Nirianne Palacpac
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Fehmi Yuksel
- Department of Microbiology, Harran University School of Medicine, Sanliurfa, Turkey
| | - Masanori Yagi
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Kaori Honjo
- Global Collaboration Center, Osaka University, Osaka, Japan
| | - Yukiko Fujita
- Laboratory of Malaria Immunology, Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Nobuko Arisue
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Satoru Takeo
- Cell-Free Science and Technology Research Center, Ehime University, Ehime, Japan
| | - Kazuyuki Tanabe
- Laboratory of Malariology, International Research Center of Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Takafumi Tsuboi
- Cell-Free Science and Technology Research Center, Ehime University, Ehime, Japan
| | - Ken J. Ishii
- Laboratory of Vaccine Science, Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Cevayir Coban
- Laboratory of Malaria Immunology, Immunology Frontier Research Center, Osaka University, Osaka, Japan
- * E-mail:
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