Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
Department of Entomology and Nematology, University of Florida, Gainesville, Florida, USA.
J Infect Dis. 2021 Aug 2;224(3):544-553. doi: 10.1093/infdis/jiaa759.
Malaria begins when Plasmodium-infected Anopheles mosquitoes take a blood meal on a vertebrate. During the initial probing process, mosquitoes inject saliva and sporozoites into the host skin. Components of mosquito saliva have the potential to influence sporozoite functionality. Sporozoite-associated mosquito saliva protein 1 (SAMSP1; AGAP013726) was among several proteins identified when sporozoites were isolated from saliva, suggesting it may have an effect on Plasmodium. Recombinant SAMSP1 enhanced sporozoite gliding and cell traversal activity in vitro. Moreover, SAMSP1 decreased neutrophil chemotaxis in vivo and in vitro, thereby also exerting an influence on the host environment in which the sporozoites reside. Active or passive immunization of mice with SAMSP1 or SAMSP1 antiserum diminished the initial Plasmodium burden after infection. Passive immunization of mice with SAMSP1 antiserum also added to the protective effect of a circumsporozoite protein monoclonal antibody. SAMSP1 is, therefore, a mosquito saliva protein that can influence sporozoite infectivity in the vertebrate host.
疟疾始于感染疟原虫的疟蚊叮咬脊椎动物。在最初的探测过程中，蚊子会向宿主皮肤注入唾液和孢子。蚊子唾液中的成分有可能影响孢子的功能。当从唾液中分离出孢子时，发现了几种蛋白质，其中包括与孢子相关的蚊子唾液蛋白 1（SAMSP1；AGAP013726），这表明它可能对疟原虫有影响。重组 SAMSP1 增强了孢子在体外的滑行和细胞穿透活性。此外，SAMSP1 减少了体内和体外的中性粒细胞趋化性，从而对孢子所在的宿主环境也产生了影响。用 SAMSP1 或 SAMSP1 抗血清对小鼠进行主动或被动免疫，可减少感染后的初始疟原虫负担。用 SAMSP1 抗血清对小鼠进行被动免疫也增加了对环子孢子蛋白单克隆抗体的保护作用。因此，SAMSP1 是一种可以影响脊椎动物宿主中孢子感染力的蚊子唾液蛋白。
