Toll样受体介导的信号通路及其与真菌性角膜炎的关系

Signal transduction pathways mediated by Toll.like receptors and their relations with fungal keratitis

Toll样受体是一类跨膜受体，它如同天然免疫的“眼睛”，监视与识别各种不同的病原体相关分子，作为联系天然免疫与获得性免疫系统的桥梁，在识别和抵御各种病原体及其产物的过程中发挥重要作用。已经报告角膜上皮细胞、基质细胞和内皮细胞内表达多种TLR。TLR胞外区识别真菌病原体相关结构后，信号经过TLR跨膜结构传入细胞内，由胞内区的TIR域启动下游信号转导，从而在真菌性角膜炎的天然免疫和获得性免疫中发挥作用。因此了解TLR信号转导通路将为真菌性角膜炎的预防和治疗提供很多特异性的新靶点。

Toll-like receptors （TLRs） were identified as transmembrane signal transduction proteins in recent years. As a group of pattern recognition receptors （ PRRs）, TLRs play important roles in the innate immunity by recognizing pathogen-associated molecular patterns （PAMPs）. Activated innate immunity subsequently leads to effective adaptive immunity. It, thereby, activites not only innate but ultimately also adaptive immunity. It has been reported that some kinds of TLRs expressed in corneal epithelial cells, stroma cells and endotheliaJ ceils. In addition to their recognition function, TLR activation triggers a complex signal transduction cascade that induces the production of inflammatory eytokines and eo-stimulatory molecules, thus initiating innate and adaptive immunity. And TLRs play an important role in innate and adaptive immunity of fungal keratitis. In summary, further studies on the regulation of intracellular signaling transduction will contribute significantly to our understanding of immunoregulation of fungal keratitis, eventually provide some way to cure the fungal infection.