The Effect of IL-4 Receptor Singaling on Inflammation and Skin Barrier Function i

特应性皮炎的发生是由于对皮肤中常见元素的不适当免疫反应。 环境辅助性T细胞II型（Th2）淋巴细胞是病理性炎症反应的关键因素。 在这些患者中观察到的反应。例如，特应性皮炎的特征在于， Th2细胞因子，IL-4和IL-13，在皮肤中。当角质形成细胞与IL-4或IL-13一起培养时， 通过产生多种促炎介质来响应，并且它们失去了丝聚蛋白的表达， 兜甲蛋白和外皮蛋白，它们是维持皮肤屏障功能的重要蛋白质。然而， 尚未进行研究来测试IL-4和IL-13直接作用于角质形成细胞的体内相关性， 与特应性皮炎相关的病理学。IL-4和IL-13通过连接共同的受体IL-13来传递信号。 4Ra。我们的假设是，角质形成细胞中特异性的IL-4Ra信号传导有助于炎症， 特应性皮炎小鼠模型中皮肤屏障功能的失效。主要目标是确定 在皮肤病理学发展中对IL-4Ra的角质形成细胞特异性表达的体内需求 与实验性特应性皮炎有关我们将通过完成两个具体的目标来实现这一目标。 目标。具体目的1：为了产生仅在哺乳动物中缺乏IL-4Ra的突变小鼠品系， 角质形成细胞我们将用我们的IL-4Ra flox/flox小鼠繁殖市售的K14-Cre小鼠。K14- Cre小鼠仅在角质形成细胞中表达Cre重组酶（Cre）。IL-4Ra flox/flox小鼠具有Crebinding IL-4Ra基因外显子7 - 9侧翼的loxP序列。当这两个品系的小鼠繁殖时， 双突变小鼠仅在角质形成细胞中表达Cre，导致角质形成细胞特异性缺失 IL-4Ra基因。除此之外，这些小鼠在其他细胞类型中具有正常的IL-4和IL-13信号传导。 具体目的2：确定在小鼠中对IL-4Rct的角质形成细胞特异性表达的体内需求。 与实验性特应性皮炎相关的皮肤病理学的发展。我们预计， 角质形成细胞特异性IL-4Ra缺失将免受炎症和皮肤屏障功能失效的影响 如在特应性皮炎的良好表征的小鼠模型中所引起的。

Atopic dermatitis occurs as a result of inappropriate immune responses to common elements in the environment. The T-helper type II (Th2) lymphocyte is a critical contributor to the pathologic inflammatory responses observed in these patients. For example, atopic dermatitis is characterized by increased levels of the Th2 cytokines, IL-4 and IL-13, in the skin. When keratinocytes are cultured with either IL-4 or IL-13 they respond by producing a variety of pro-inflammatory mediators and they lose expression of filaggrin as well as loricrin and involucrin, which are important proteins that maintain skin barrier function. However, there have been no studies performed to test the in vivo relevance of IL-4 and IL-13 acting directly on keratinocytes in the pathologies associated with atopic dermatitis. IL-4 and IL-13 signal by ligation of a common receptor, IL- 4Ra. Our hypothesis is that IL-4Ra signaling specifically in keratinocytes contributes to inflammation and failure of skin barrier function in a murine model of atopic dermatitis. The main objective is to determine the in vivo requirement for keratinocyte-specific expression of IL-4Ra in the development of skin pathologies associated with experimental atopic dermatitis. We will accomplish this objective by completing two specific aims. Specific Aim 1: To generate a mutant mouse strain that is deficient in IL-4Ra exclusively in keratinocytes. We will breed commercially available K14-Cre mice with our IL-4Ra flox/flox mice. The K14- Cre mice have expression of Cre-recombinase (Cre) only in keratinocytes. IL-4Ra flox/flox mice have Crebinding loxP sequences that flank exons 7 -9 of the IL-4Ra gene. When the two strains of mice are bred, the double mutant mice have expression of Cre only in keratinocytes causing keratinocyte-specific deletion of the IL-4Ra gene. Otherwise, these mice have normal IL-4 and IL-13 signaling in every other cell type. Specific Aim 2: To determine the in vivo requirement for keratinocyte-specific expression of IL-4Rct in the development of skin pathology associated with experimental atopic dermatitis. We anticipate that mice with keratinocyte-specific IL-4Ra deletion will be protected from inflammation and failure of skin barrier function as elicited in a well-characterized mouse model of atopic dermatitis.