Keratinocyte TLR in Cutaneous Immunity

描述（由申请人提供）：表皮是皮肤抵御微生物感染的第一道防线。我们最近报道了人类角膜上皮细胞以及人和小鼠角质形成细胞能够表达一个最近描述的受体家族，称为toll样受体（TLRs）。迄今为止，大多数已发表的研究都研究了TLR在白细胞中的表达和功能。对TLR在非白细胞如角质形成细胞中的作用知之甚少。在本应用中，我们将利用体外和体内小鼠模型系统来验证以下假设：1)角质细胞TLR2和TLR4在宿主皮肤防御革兰氏（+）和革兰氏（-）病原体金黄色葡萄球菌和铜绿假单胞菌中发挥重要作用。2)这些保护性抗菌反应是由金黄色葡萄球菌和铜绿假单胞菌的特定成分激活角质形成细胞TLR2和TLR4介导的，这些成分启动了强效抗菌先天免疫效应蛋白的局部表达和产生。3)角质形成细胞TLR2和TLR4的表达或功能缺陷会导致表皮对金黄色葡萄球菌和铜绿假单胞菌的先天免疫保护反应改变，可能导致进行性皮肤感染过程，导致这些细菌病原体的全身传播导致发病率增加甚至死亡。这些假设将在以下特定目标中得到验证：特定目标#1：检测培养的小鼠角质形成细胞中TLR2和TLR4的表达和功能对革兰氏（+）和革兰氏（-）细菌、源自这些细菌的结构成分以及选定的促炎和免疫抑制剂的反应。特异性目标#2：评估在培养的小鼠角质形成细胞中，TLR2和TLR4介导的先天免疫反应对致病性革兰氏（+）和革兰氏（-）细菌和源自这些细菌的结构成分的反应。特异性目的#3：确定小鼠角化细胞TLR2和TLR4在介导宿主对革兰氏（+）和革兰氏（-）细菌感染和细菌衍生成分的保护性表皮先天免疫反应中的体内作用。小鼠角质形成细胞对致病菌的反应将与对皮肤共生细菌的反应进行比较，并在人类角质形成细胞中得到证实。我们相信，我们的研究将导致新的见解皮肤先天免疫和管理范围广泛的炎症和传染性疾病的皮肤。

DESCRIPTION (provided by applicant): The epidermis is the first line of defense against microbial infections of the skin. We recently reported that human corneal epithelial cells as well as human and murine keratinocytes are capable of expressing a family of recently described receptors termed Toll-like receptors (TLRs). To date, most published studies have examined the expression and function of TLR in leukocytes. Much less is known about the role of TLR in non-leukocytes such as keratinocytes. In this application we will utilize both an in vitro and in vivo murine model system to test the following hypotheses : 1) Keratinocyte TLR2 and TLR4 play an essential role in host cutaneous defenses to the gram (+) and gram (-) pathogens Staphylococcus aureus and Pseudomonas aeruginosa. 2) These protective anti-bacterial responses are mediated by activation of keratinocyte TLR2 and TLR4 by specific components of Staphylococcus aureus and Pseudomonas aeruginosa that initiate the local expression and production of potent antimicrobial innate immune effector proteins. 3) Defects in the expression or function of keratinocyte TLR2 and TLR4 will result in altered epidermal innate immune protective responses to S. aureus and P. aeruginosa that may lead to a progressive cutaneous infectious process causing increased morbidity and even death as a result of systemic spread of these bacterial pathogens. These hypotheses will be tested in the following specific aims: Specific Aim #1: To examine the expression and function of TLR2 and TLR4 in cultured murine keratinocytes in response to gram (+) and gram (-) bacteria, structural components derived from these bacteria, as well as selected proinflammatory and immunosuppressive agents. Specific Aim #2: To assess selected TLR2 and TLR4 mediated innate immune responses in cultured murine keratinocytes in response to pathogenic gram (+) and gram (-) bacteria and structural components derived from these bacteria. Specific Aim #3: To determine the in vivo role of murine keratinocyte TLR2 and TLR4 in mediating host protective epidermal innate immune responses to gram (+) and gram (-) bacterial infection and bacterial-derived components. Murine keratinocyte responses to pathogenic bacteria will be compared to responses to cutaneous commensal bacteria and confirmed in human keratinocytes. We believe that our studies will lead to novel insights into cutaneous innate immunity and the management of a wide range of inflammatory and infectious diseases in the skin.