弓形虫与疟原虫入侵引起宿主细胞骨架重组相关GTP酶不同定位的观察

Observation on different localization of GTPases related to host cytoskeleton reorganization triggered by Toxoplasma gondii and Plasmodium falciparum infection

目的方法,结果,结论弓形虫与疟原虫均是顶复门(Phylum Apicomplexa),孢子纲(Class Sporozoea),真球虫目(Order Eucoccidiida)的细胞内寄生原虫,入侵宿主细胞后均寄生于纳虫泡内进行发育增殖。细胞内寄生原虫的入侵均需要宿主细胞的细胞骨架发生重组,RhoGTP酶是哺乳动物细胞(有核细胞及红细胞)调节细胞骨架重组的重要酶类。我们在研究中发现宿主细胞的RhoA及Rac1GTP酶在弓形虫速殖子侵染后被纳入了纳虫泡膜(Parasitophorous Vacuole Membrane,PVM)上并高丰度聚集,然而在疟原虫裂殖子侵染的红细胞内却没有发现这两种GTP酶在纳虫泡膜上聚集的现象。宿主细胞RhoA及Rac1GTP酶在弓形虫及疟原虫感染宿主细胞后的不同分布,显示这两种原虫感染引起宿主细胞骨架重组的途径是不同的。

Both Toxoplasma gondii and Plasmodium spp.belong to the intracellular protozoa in Order Eucoccidiida,Class Sporozoea,and Phylum Apicomplexa.They dwell in the parasitophorous vacuole for parasitism,development and multiplication after recruitment.The invasion of these intracellular protozoans into host cells requires the cytoskeleton reorganization of the host cell.Rho GTPases are the important enzymes in regulation of cytoskeleton reorganization in mammalian cells including nucleated cells and erythrocytes.We found in our research that host cell RhoA and Rac1 GTPase were recruited to the parasitophorous vacuole membrane（PVM） of T.gondii and showed a high accumulation on the PVM after T.gondii tachyzoite invading the host cell.On the other hand,this accumulation of the Rho GTPases on the PVM was not observed after Plasmodium falciparum merozoites invading erythrocytes.The different distribution of RhoA and Rac1GTPase in the host cell after the invasion of T.gondii tachyzoites and Plasmodium falciparum merozoites indicated the different way for the regulation of cytoskeleton reorganization in host cells upon the parasites invasion.