West African Center for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Legon, Accra.
Department of Biochemistry, Kogi State University, Anyigba, Nigeria.
J Infect Dis. 2018 Jul 24;218(5):778-790. doi: 10.1093/infdis/jiy222.
Plasmodium falciparum erythrocyte invasion is a multistep process that involves a spectrum of interactions that are not well characterized. We have characterized a 113-kDa immunogenic protein, PF3D7_1431400 (PF14_0293), that possesses coiled-coil structures. The protein is localized on the surfaces of both merozoites and gametocytes, hence the name Plasmodium falciparum surface-related antigen (PfSRA). The processed 32-kDa fragment of PfSRA binds normal human erythrocytes with different sensitivities to enzyme treatments. Temporal imaging from initial attachment to internalization of viable merozoites revealed that a fragment of PfSRA, along with PfMSP119, is internalized after invasion. Moreover, parasite growth inhibition assays showed that PfSRA P1 antibodies potently inhibited erythrocyte invasion of both sialic acid-dependent and -independent parasite strains. Also, immunoepidemiological studies show that malaria-infected populations have naturally acquired antibodies against PfSRA. Overall, the results demonstrate that PfSRA has the structural and functional characteristics of a very promising target for vaccine development.
恶性疟原虫红细胞入侵是一个多步骤的过程，涉及一系列尚未很好描述的相互作用。我们已经鉴定了一种 113kDa 的免疫原性蛋白，PF3D7_1431400（PF14_0293），它具有卷曲螺旋结构。该蛋白定位于裂殖子和配子体的表面，因此被称为恶性疟原虫表面相关抗原（PfSRA）。PfSRA 的加工后 32kDa 片段与正常人类红细胞结合，对酶处理的敏感性不同。从初始附着到有活力的裂殖子内化的时间成像显示，PfSRA 的一个片段与 PfMSP119 一起在入侵后被内化。此外，寄生虫生长抑制测定表明，PfSRA P1 抗体强烈抑制依赖唾液酸和不依赖唾液酸的寄生虫株的红细胞入侵。同样，免疫流行病学研究表明，疟疾感染人群自然获得了针对 PfSRA 的抗体。总的来说，这些结果表明 PfSRA 具有结构和功能特征，是疫苗开发的一个很有前途的目标。
