弓形虫入侵的宿主细胞骨架重塑触发线粒体重新分布

Cytoskeleton rearrangement and mitochondria re-distribution of host cells in Toxoplasma gondii invasion

目的探讨宿主细胞骨架重塑在弓形虫侵入HFF细胞以及触发细胞线粒体重新分布中的作用。方法体外培养HFF细胞,预先用1μg/mL细胞松驰素D(CD)处理30min,接种弓形虫速殖子分别培养1h和20h,Western blotting检测弓形虫表面抗原(surface antigen,SAG)1蛋白表达。同时用MitoTrackerRed CMXRos荧光探针标记细胞线粒体,激光共聚焦显微镜下观察HFF细胞线粒体在弓形虫侵入前后和CD处理前后聚集和分布情况。结果感染后1h,CD处理组HFF细胞内虫体量与CD未处理组差异不大,20h时CD未处理组细胞内虫体量显著多于CD处理组。此时可见HFF细胞线粒体明显聚集成明亮点状且分布于纳虫泡周围,而未感染组细胞线粒体未见明显聚集分布。CD可以显著抑制弓形虫侵入HFF细胞后引起的线粒体聚集。结论触发宿主细胞骨架重塑是弓形虫侵入宿主细胞并引起细胞线粒体向纳虫泡聚集所必须的。

We explored the role of host cell cytoskeleton rearrangement in mitochondria re-distribution during Toxoplasma gondii invasion. HFF cells were treated with cytochalasin D （CD） for 30 min, and T, gondii tachzyoites were co-cultured with HFF cells for 1 h and 20 h, respectively. After co-culture, the tachyzoite SAG1 protein was determined by Western blotting. The HFF cell mitochondria were labeled by MitoTracker Red CMXRos fluorescence probe. The HFF cell mitochondria distri- bution was observed by Confocal microscope in T. gondii infected group and CD treated group. After infection for 1 h, the number of T. gondii tachyzoites had no significant difference between CD treated group and normal group. After infected for 20 h, the number of T. gondii tachyzoites in normal group was much more than that in CD treated group. After 20 h^s infection, the bright point type of mitochondria gathered beside parasitophorous vacuoles （PVs） in infected group. In normal group, we did not observe the mitochondria aggregation. However, HFF cell mitochondria rearrangement triggered by T. gondii could be suppressed by cytochalasin D. Triggering of host cell cytoskeleton rearrangement is necessary for T. gondii prolifera- tion and host cell mitochondria rearrangement to PVs.