Payne T Matthew, Lund Peder J, Knoll Laura J
Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States.
Mol Biochem Parasitol. 2011 Oct;179(2):107-10. doi: 10.1016/j.molbiopara.2011.05.008. Epub 2011 Jun 2.
To identify Toxoplasma gondii genes important in the establishment of a persistent infection, we previously used signature-tagged mutagenesis to identify mutants with reduced cyst numbers in the brains of mice. One of the mutants, 95C5, has an insertion within a predicted six transmembrane domain protein, which localizes to the parasite pellicle, thus we named it transmembrane pellicle protein 1 (TgTPP1). Although the 95C5 mutant was found be reduced in its ability to form brain cysts, it is defective during acute infection. Addition of TgTPP1 expressed from its endogenous promoter restored the acute lethality of the 95C5 mutant to parental levels. The 95C5 mutant does not have a growth defect in standard tissue culture conditions; however, we found a significant defect in host cell penetration after extracellular stress. Overall, TgTPP1 may function during acute infection by enhancing the parasites ability to invade after extracellular stress.
为了鉴定在建立持续性感染中起重要作用的刚地弓形虫基因，我们之前利用签名标签诱变技术来鉴定在小鼠脑中包囊数量减少的突变体。其中一个突变体95C5，在一个预测的六跨膜结构域蛋白内有插入，该蛋白定位于寄生虫表膜，因此我们将其命名为跨膜表膜蛋白1（TgTPP1）。尽管发现95C5突变体形成脑包囊的能力降低，但其在急性感染期间存在缺陷。从其内源启动子表达的TgTPP1的添加将95C5突变体的急性致死率恢复到亲本水平。95C5突变体在标准组织培养条件下没有生长缺陷；然而，我们发现在细胞外应激后宿主细胞穿透存在显著缺陷。总体而言，TgTPP1可能在急性感染期间通过增强寄生虫在细胞外应激后入侵的能力发挥作用。
