Development of experimental model for surface antigens of human malaria parasite

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K19434
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 49:Pathology, infection/immunology, and related fields
• Research Institution: Osaka University
• Principal Investigator: IWANAGA SHIROH 大阪大学, 微生物病研究所, 教授 (20314510)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: マラリア原虫 / 感染赤血球表面抗原 / 動物モデル

Outline of Final Research Achievements

Among human malaria parasites, Plasmodium falciparum is the most virulent, causing severe symptoms such as fever, splenomegaly, and cerebral malaria　a serious condition characterized by coma due to specific brain dysfunction. The parasite's genome contains numerous red blood cell surface antigen molecules (approximately 60 types of PfEMP1, about 200 types of RIFIN, and around 30 types of STEVOR), which the parasite uses to evade and suppress the host's immune system and to exhibit pathogenicity. However, because Plasmodium falciparum infects only humans, there is an urgent need to develop effective animal models. In this study, we successfully expressed RIFIN on the surface of red blood cells infected with rodent malaria parasites. The development of an animal model using this system is anticipated in the future.

Free Research Field

寄生虫学

Academic Significance and Societal Importance of the Research Achievements

本研究では熱帯熱マラリア研究の動物モデルを開発することを目標とし、熱帯熱マラリア原虫の感染赤血球表面抗原の一つであるRIFINをネズミマラリア原虫の感染赤血球表面に発現することを試みた。具体的にはネズミマラリア原虫の感染赤血球膜に局在するPbEMAP1にRIFINを融合発現する組換え原虫を作製した。最終的に2種類のRIFINについて、これらを感染赤血球表面に発現する原虫を作製した。この成果によってこれまで不可能であった熱帯熱マラリア原虫の感染赤血球表面抗原のin vivo研究が可能となり、ワクチン開発の重要な研究ツールとなると考えられた。