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Zhang B, Feng H, Zhao Y, Zhang D, Yu X, Li Y, Zeng Y, Thongpoon S, Roobsoong W, Wu Y, Liu F, Sattabongkot J, Min H, Cui L, Cao Y. Evaluation of transmission-blocking potential of PvPSOP25 using transgenic murine malaria parasite and clinical isolates. PLoS Negl Trop Dis 2024; 18:e0012231. [PMID: 38865344 PMCID: PMC11168624 DOI: 10.1371/journal.pntd.0012231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Accepted: 05/21/2024] [Indexed: 06/14/2024] Open
Abstract
BACKGROUND Malaria transmission-blocking vaccines (TBVs) aim to inhibit malaria parasite development in mosquitoes and prevent further transmission to the human host. The putative-secreted ookinete protein 25 (PSOP25), highly conserved in Plasmodium spp., is a promising TBV target. Here, we investigated PvPSOP25 from P. vivax as a TBV candidate using transgenic murine parasite P. berghei and clinical P. vivax isolates. METHODS AND FINDINGS A transgenic P. berghei line expressing PvPSOP25 (TrPvPSOP25Pb) was generated. Full-length PvPSOP25 was expressed in the yeast Pichia pastoris and used to immunize mice to obtain anti-rPvPSOP25 sera. The transmission-blocking activity of the anti-rPvPSOP25 sera was evaluated through in vitro assays and mosquito-feeding experiments. The antisera generated by immunization with rPvPSOP25 specifically recognized the native PvPSOP25 antigen expressed in TrPvPSOP25Pb ookinetes. In vitro assays showed that the immune sera significantly inhibited exflagellation and ookinete formation of the TrPvPSOP25Pb parasite. Mosquitoes feeding on mice infected with the transgenic parasite and passively transferred with the anti-rPvPSOP25 sera showed a 70.7% reduction in oocyst density compared to the control group. In a direct membrane feeding assay conducted with five clinical P. vivax isolates, the mouse anti-rPvPSOP25 antibodies significantly reduced the oocyst density while showing a negligible influence on mosquito infection prevalence. CONCLUSIONS This study supported the feasibility of transgenic murine malaria parasites expressing P. vivax antigens as a useful tool for evaluating P. vivax TBV candidates. Meanwhile, the moderate transmission-reducing activity of the generated anti-rPvPSOP25 sera necessitates further research to optimize its efficacy.
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Affiliation(s)
- Biying Zhang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Hao Feng
- Department of Ophthalmology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Yan Zhao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Di Zhang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Xinxin Yu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Yusi Li
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Ying Zeng
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Sataporn Thongpoon
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Wanlapa Roobsoong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Yudi Wu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Fei Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Hui Min
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
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Thongpoon S, Roobsoong W, Nguitragool W, Chotirat S, Tsuboi T, Takashima E, Cui L, Ishino T, Tachibana M, Miura K, Sattabongkot J. Naturally Acquired Transmission-Blocking Immunity Against Different Strains of Plasmodium vivax in a Malaria-Endemic Area in Thailand. J Infect Dis 2024; 229:567-575. [PMID: 37943633 PMCID: PMC10873188 DOI: 10.1093/infdis/jiad469] [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: 04/27/2023] [Revised: 09/30/2023] [Accepted: 11/04/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Human immunity triggered by natural malaria infections impedes parasite transmission from humans to mosquitoes, leading to interest in transmission-blocking vaccines. However, immunity characteristics, especially strain specificity, remain largely unexplored. We investigated naturally acquired transmission-blocking immunity (TBI) against Plasmodium vivax, a major malaria parasite. METHODS Using the direct membrane-feeding assay, we assessed TBI in plasma samples and examined the role of antibodies by removing immunoglobulins through protein G/L adsorption before mosquito feeding. Strain specificity was evaluated by conducting a direct membrane-feeding assay with plasma exchange. RESULTS Blood samples from 47 patients with P vivax were evaluated, with 37 plasma samples successfully infecting mosquitoes. Among these, 26 showed inhibition before immunoglobulin depletion. Despite substantial immunoglobulin removal, 4 samples still exhibited notable inhibition, while 22 had reduced blocking activity. Testing against heterologous strains revealed some plasma samples with broad TBI and others with strain-specific TBI. CONCLUSIONS Our findings indicate that naturally acquired TBI is mainly mediated by antibodies, with possible contributions from other serum factors. The transmission-blocking activity of plasma samples varied by the tested parasite strain, suggesting single polymorphic or multiple targets for naturally acquired TBI. These observations improve understanding of immunity against P vivax and hold implications for transmission-blocking vaccine development.
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Affiliation(s)
| | | | - Wang Nguitragool
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Tomoko Ishino
- Department of Parasitology and Tropical Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Mayumi Tachibana
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
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