Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA.
Infect Immun. 2012 May;80(5):1753-8. doi: 10.1128/IAI.05862-11. Epub 2012 Feb 21.
Cryptosporidium parvum is an opportunistic pathogen in AIDS patients. It is an intracellular but extracytoplasmic parasite residing in a host cell-derived parasitophorous vacuole. It is still poorly understood how this parasite interacts with host cells. We observed that expression of the integrin α2 (ITGA2) gene in host cells was significantly upregulated upon C. parvum infection, and a higher level of ITGA2 protein was present in the parasite infection sites. The infection could be reduced by the treatment of antibodies against ITGA2 and integrin β1 (ITGB1) subunits, as well as by type I collagen (an integrin α2β1 ligand). We also generated stable knockdown of ITGA2 gene expression in HCT-8 cells and observed consistent reduction of parasite infection in these knockdown cells. Collectively, our evidence indicates that host cell ITGA2 might be involved in interacting with Cryptosporidium during infection, probably acting as part of the regulatory elements upstream of the reported recruiting and reorganization of F actin at the infection sites.
微小隐孢子虫是 AIDS 患者中的机会性病原体。它是一种存在于宿主细胞来源的吞噬小泡中的细胞内但细胞外寄生虫。目前人们对这种寄生虫如何与宿主细胞相互作用还知之甚少。我们观察到，微小隐孢子虫感染后宿主细胞中整合素 α2（ITGA2）基因的表达显著上调，并且寄生虫感染部位存在更高水平的 ITGA2 蛋白。用针对整合素 α2β1 亚基的 ITGA2 和 ITGB1 抗体以及 I 型胶原（整合素 α2β1 配体）处理可以减少感染。我们还在 HCT-8 细胞中稳定敲低 ITGA2 基因的表达，观察到这些敲低细胞中寄生虫感染的一致减少。总的来说，我们的证据表明，宿主细胞 ITGA2 可能参与感染期间与隐孢子虫的相互作用，可能作为报告的在感染部位招募和重组 F 肌动蛋白的上游调节元件的一部分发挥作用。
