Cardoso Rita, Wang Junhua, Müller Joachim, Rupp Sebastian, Leitão Alexandre, Hemphill Andrew
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, 3012, Switzerland; Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal.
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, 3012, Switzerland.
Exp Parasitol. 2018 Apr;187:75-85. doi: 10.1016/j.exppara.2018.02.008. Epub 2018 Feb 27.
Like most intracellular pathogens, the apicomplexan parasites Besnoitia besnoiti, Toxoplasma gondii and Neospora caninum scavenge metabolites from their host cells. Recruitment of the Golgi complex to the vicinity of the parasitophorous vacuole (PV) is likely to aid in this process. In this work, we comparatively assessed B. besnoiti, T. gondii and N. caninum infected human retinal pigmented epithelial (hTERT-RPE-1) cells at 24 h post-infection and used antibodies to confirm Golgi ribbon compaction in B. besnoiti, and Golgi ribbon dispersion in T. gondii, while no alteration in Golgi morphology was seen in N. caninum infected cells. In either case, the Golgi stacks of infected cells contained both cis- (GM130) and trans- (TGN46) Golgi proteins. The localization of Rab9A, an important regulator of endosomal trafficking, was also studied. GFP-tagged Rab9A was recruited to the vicinity of the PV of all three parasites. Toxoplasma-infected cells exhibited increased expression of Rab9A in comparison to non-infected cells. However, Rab9A expression levels remained unaltered upon infection with N. caninum and B. besnoiti tachyzoites. In contrast to Rab9A, a GFP-tagged dominant negative mutant form of Rab9A (Rab9A DN), was not recruited to the PV, and the expression of Rab9A DN did not affect host cell invasion nor replication by all three parasites. Thus, B. besnoiti, T. gondii and N. caninum show similarities but also differences in how they affect constituents of the endosomal/secretory pathways.
与大多数细胞内病原体一样，顶复门寄生虫贝氏贝诺孢子虫、刚地弓形虫和犬新孢子虫会从宿主细胞中清除代谢产物。高尔基体复合体向寄生泡（PV）附近募集可能有助于这一过程。在本研究中，我们比较评估了感染贝氏贝诺孢子虫、刚地弓形虫和犬新孢子虫24小时后的人视网膜色素上皮（hTERT-RPE-1）细胞，并使用抗体证实了贝氏贝诺孢子虫感染细胞中高尔基体带的压缩，以及刚地弓形虫感染细胞中高尔基体带的分散，而在犬新孢子虫感染的细胞中未观察到高尔基体形态的改变。在这两种情况下，感染细胞的高尔基体堆叠中都含有顺面（GM130）和反面（TGN46）高尔基体蛋白。我们还研究了内体运输的重要调节因子Rab9A的定位。绿色荧光蛋白标记的Rab9A被募集到所有三种寄生虫寄生泡的附近。与未感染细胞相比，弓形虫感染的细胞中Rab9A的表达增加。然而，犬新孢子虫和贝氏贝诺孢子虫速殖子感染后，Rab9A的表达水平保持不变。与Rab9A相反，绿色荧光蛋白标记的Rab9A显性负突变体形式（Rab9A DN）未被募集到寄生泡，Rab9A DN的表达也不影响所有三种寄生虫对宿主细胞的入侵和复制。因此，贝氏贝诺孢子虫、刚地弓形虫和犬新孢子虫在影响内体/分泌途径成分方面既有相似之处，也有不同之处。
