Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil.
The University of Queensland Diamantina Institute, Faculty of Medicine, The University of Queensland, Woolloongabba, QLD, Australia.
J Eukaryot Microbiol. 2022 May;69(3):e12903. doi: 10.1111/jeu.12903. Epub 2022 Mar 31.
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.
克氏锥虫循环型和组织培养型锥鞭毛体入侵宿主细胞是一个复杂的过程，涉及到宿主-寄生虫细胞和分子的相互作用。特别是，宿主细胞肌动蛋白细胞骨架在锥鞭毛体入侵过程中的参与作用还没有得到充分的研究，而且结果仍然存在争议。在本工作中，我们同时比较了这两种锥鞭毛体形式，并采用了最先进的活细胞成像技术，首次显示了宿主细胞肌动蛋白细胞骨架在 MT 和 TCT 入侵部位的动态动员。此外，细胞松弛素 D、拉曲库林 B 和 jasplakinolide 预处理细胞抑制了 MT 和 TCT 的入侵。此外，我们的结果表明，RhoA、Rac1 和 Cdc-42 GTPase 耗尽的细胞中 TCT 的入侵减少，而只有 Cdc42 和 RhoA 耗尽的细胞中 MT 的入侵减少。有趣的是，这三种研究的 GTPase 的耗竭诱导溶酶体在整个细胞质中分散分布。这些观察结果表明，尽管溶酶体扩散在锥鞭毛体入侵中很重要，但 GTPase 的耗竭足以损害寄生虫的入侵。总之，我们的结果表明，宿主细胞肌动蛋白细胞骨架在 TCT 和 MT 入侵过程中发挥直接作用。
