克氏锥虫的细胞侵袭是一个复杂的过程,涉及宿主-寄生虫的细胞和分子相互作用。特别是,在锥虫侵袭过程中,宿主细胞肌动蛋白细胞骨架的参与研究甚少,而且仍然,结果是有争议的。在目前的工作中,我们并排比较了两种锥虫形式,并采用了最新的活细胞成像技术,首次显示了宿主细胞肌动蛋白细胞骨架向MT和TCT侵袭位点的动态动员。此外,细胞松弛素D,latrunculinB,茉莉酚预处理细胞抑制MT和TCT侵袭。此外,我们的结果表明,TCT侵袭在RhoA中减少,Rac1和Cdc-42GTP酶耗竭细胞,而MT侵袭仅在Cdc42和RhoA耗竭细胞中减少。有趣的是,所研究的三种GTP酶的消耗诱导了整个细胞质中分散的溶酶体分布。这些观察结果表明,尽管溶酶体在锥虫入侵中传播很重要,但GTP酶的消耗足以削弱寄生虫的入侵。一起,我们的结果表明,宿主细胞肌动蛋白细胞骨架在TCT和MT侵袭中起直接作用。
Cellular invasion by Trypanosoma cruzi metacyclic trypomastigotes (MTs) or tissue culture trypomastigotes (TCTs) is a complex process involving host-parasite cellular and molecular interactions. Particularly, the involvement of host cell actin cytoskeleton during trypomastigote invasion is poorly investigated, and still, the results are controversial. In the present work, we compare side by side both trypomastigote forms and employ state-of-the-art live-cell imaging showing for the first time the dynamic mobilization of host cell actin cytoskeleton to MT and TCT invasion sites. Moreover, cytochalasin D, latrunculin B, and jasplakinolide-pretreated cells inhibited MT and TCT invasion. Furthermore, our results demonstrated that TCT invasion decreased in RhoA, Rac1, and Cdc-42 GTPase-depleted cells, whereas MT invasion decreased only in Cdc42-and RhoA-depleted cells. Interestingly, depletion of the three studied GTPases induced a scattered lysosomal distribution throughout the cytosol. These observations indicate that GTPase depletion is sufficient to impair parasite invasion despite the importance of lysosome spread in trypomastigote invasion. Together, our results demonstrate that the host cell actin cytoskeleton plays a direct role during TCT and MT invasion.