Role of Toll-Like Receptors in Bacterial Keratitis

描述(由申请人提供)：铜绿假单胞菌是一种与细菌性角膜炎有关的常见微生物，尤其是在长期配戴隐形眼镜的用户中。在美国，每年微生物角膜炎的发病率为25,000-30,000例，治疗成本估计为1,500-3,000万美元，这使得这种疾病具有相当大的医疗和经济影响。在拟议的研究中，我们将检验总体假设，即Toll样受体/白细胞介素1受体(TLR/IL-IR)及其相关分子(如CD14)在角膜初始(天然)免疫反应中发挥关键作用，并导致B6和BALB/c小鼠感染铜绿假单胞菌的不同结局。没有其他实验室正在使用细菌性(非无菌)角膜炎模型来研究这一受体家族在眼睛中的作用。1)TLR/IL-1RS(TLR-4、-9、ST2和SIGIRR)及其相关分子(CD14、MD2)在正常和/或铜绿假单胞菌感染的BALB/c小鼠角膜上皮和基质中的表达水平/分布不同；2)细菌感染后敏感和耐药小鼠的TLR/IL1-R MyD88和TRIF信号通路优先激活；B6/BALB/c小鼠感染角膜中TLR/IL-1RS及其信号分子对获得性免疫(Th1/Th2应答)的调节作用不同。因此，这项研究的目的是阐明TLR/IL-1R在实验性铜绿假单胞菌角膜感染导致角膜穿孔(B6)与愈合(BALB/c)的先天和获得性免疫反应中的作用。在拟议的研究中，将使用多种方法，包括使用体内和体外模型来测试TLR的表达水平、分布、信号和免疫调节特性。预计这些发现将揭示早期干预和/或治疗铜绿假单胞菌角膜炎的潜在目标。

DESCRIPTION (provided by applicant): Pseudomonas aeruginosa (P. aeruginosa) is a common organism associated with bacterial keratitis, especially in extended wear contact lens users. In the United States, the incidence of microbial keratitis is 25,000-30,000 cases annually with cost of treatment estimated at $15-30 million, making the disease of considerable medical and economic impact. In the studies proposed, we will test the overall hypothesis that Toll-like receptor/interleukin-1 receptor (TLR/IL-IR) and their associated molecules (e.g., CD14) play a critical role in the initial (innate) immune response in the cornea and are responsible for the disparate outcome to P. aeruginosa infection of B6 and BALB/c mice. No other laboratory is studying the role of this family of receptors in the eye using a bacterial (non-sterile) keratitis model. Three aims are proposed that will test the hypotheses that: 1) expression levels/distribution of TLR/IL-1Rs (TLR-4, -9, ST2 and SIGIRR) and related molecules (CD14, MD2) in epithelium and stroma are disparate in B6 and BALB/c mice in normal and/or P. aeruginosa infected cornea; 2) the TLR/IL1-R MyD88 vs. TRIF signaling pathway is preferentially activated in susceptible vs. resistant mice after bacterial infection; and 3) adaptive immunity (Th1 vs. Th2 responsiveness) is regulated disparately by TLR/IL-1Rs and their signaling molecules in the infected cornea of B6 vs. BALB/c mice. Thus, the goal of the studies proposed in this application is to elucidate the role of TLR/IL-1R in the innate and adaptive immune response to experimental P. aeruginosa corneal infection resulting in corneal perforation (B6) vs. healing (BALB/c). In the proposed studies, multiple approaches will be used and include use of both in vivo and in vitro models to test TLR expression levels, distribution, signaling and immunoregulatory properties. It is expected that the findings will reveal potential targets for early intervention and/or treatment of P. aeruginosa keratitis.