2020 Fiscal Year Annual Research Report

Comprehensive analysis of antibody responses to Plasmodium falciparum repetitive interspersed family (RIFIN) proteins

Research Project

Project/Area Number	19K16630
Research Institution	Ehime University
Principal Investigator	Nganga KanoiBernard 愛媛大学, プロテオサイエンスセンター, 特定研究員 (30824817)
Project Period (FY)	2019-04-01 – 2021-03-31
Keywords	Malaria / Immunity / Falciparum
Outline of Annual Research Achievements	This study aimed at assessing the the specific proteins that are targets of naturally acquired immunity against Plasmodium falciparum clinical malaria in individuals residing in a malaria endemic region in Uganda. In the initial phase, we observed that >98% of assayed proteins were immunogenic in malaria-exposed individuals in Uganda. Children with high levels of antibodies to four RIFINs a STEVOR, and SURFIN 1.2 displayed reduced the risk of developing clinical malaria. Subsequently, we observed that antibodies to a potential vaccine antigen, PF3D7_0801000 which localizes in merozoites, inhibit P. falciparum parasite growth in in vitro culture. The protein is strongly immunoreactive with serum obtained from a malaria-exposed Ugandan population, with antibody acquisition increasing with age. The selected proteins need further evaluation as asexual blood-stage vaccine candidate antigens. These and other findings were summarized in Kanoi et al (2021). Leveraging the wheat germ cell-free protein synthesis system to accelerate malaria vaccine development. Parasitol Int 80, 102224, doi:10.1016/j.parint.2020.102224.