Regulation of Cutaneous Inflammation by local gd T Cells

描述（由申请人提供）：在鸡、小鼠和人等多种物种中，大量T细胞与体表上皮细胞（如肠道、泌尿生殖道和皮肤）组成性相关。这种上皮内淋巴细胞（IEL）通常富含T细胞受体（TCR）γ/δ +细胞，通常具有有限的组织相关抗原受体多样性;因此，小鼠皮肤中的大多数IEL，也称为树突状表皮T细胞（DETC），表达显著同质的V γ 5/Vdelta 1 TCR，其显著特点是缺乏连接（CDR 3区）多样性。不同TCRd-/-菌株的联合使用（敲除）小鼠和通过过继转移选择性重建这种小鼠的研究表明，V γ 5 + DETC，而不是其他γ/δ细胞，是几种生理相关的皮肤炎症反应的有效下调因子，包括局部的、遗传依赖性的、TCR α/β + T细胞依赖性的、环境依赖性的、与人类特应性皮炎有几个共同特征的慢性皮炎。该项目的长期目标是利用这个强大的实验模型来定义局部T细胞调节局部组织内全身免疫反应的作用的机制。该项目的具体目标是：1。为了详细表征通常由DETC下调的皮肤炎症，使用：a）免疫组织学、离体流式细胞术和微阵列分析; B）易感δ-/-小鼠与δ-/-小鼠的表型比较，所述δ-/-小鼠也通过用细胞因子拮抗剂或阻断抗体治疗或第二“敲除”遗传突变2而缺乏所选促炎细胞和/或分子。通过基因表达系列分析（SAGE）表征“静息”DETC和体外“活化”DETC表达的基因，通过定量RT-PCR对各种体内和体外活化状态下的DETC进行验证，并将此类基因表达模式与肠道相关γ/δ +和α/β + IEL以及系统性CD 8 + α/β +“幼稚”和“记忆”T细胞的基因表达模式进行比较。3.通过用缺乏候选抗炎分子的胎儿胸腺DETC前体重建δ-/-受体，研究选定的候选DETC抗炎细胞因子/效应分子。4.利用全基因组微卫星定位来鉴定控制某些d-/-小鼠（而非其他d-/-小鼠）发生自发性皮炎的易感性/抗性的遗传区间，随后进行额外研究（同源系的开发，该区间内所含基因的差异表达分析），旨在明确鉴定调节皮肤炎症的基因。

DESCRIPTION (provided by applicant): In species as diverse as chickens, mice, and humans, substantial numbers of T cells are constitutively associated with body surface epithelia, such as the gut, genitourinary tract, and the skin. Such intraepithelial lymphocytes (IELs) are commonly enriched in T cell receptor (TCR)gamma/delta+ cells, frequently with limited tissue associated antigen receptor diversity; thus, most IELs in mouse skin, also known as dendritic epidermal T cells (DETC), express strikingly homogeneous Vgamma5/Vdelta1 TCRs notable for their lack of junctional (CDR3 region) diversity. Combined use of different strains of TCRd-/- (knockout) mice and selective reconstitution of such mice via adoptive transfer has shown that Vgamma5+ DETC, but not other gamma/delta cells, are potent down-regulators of several physiologically relevant, cutaneous inflammatory responses, including a localized, genetically-dependent, TCRalpha/beta+ T cell-dependent environmentally-dependent, chronic dermatitis that shares several features of human atopic dermatitis. The long-term goal of this project is to utilize this powerful experimental model to define the mechanisms by which local T cells regulate the effects of systemic immune responses within local tissues. The specific aims of this project are: 1. To characterize in detail the cutaneous inflammation normally down-regulated by DETC) using: a) immunohistology, ex vivo flow cytometry, and microarray analysis; b) phenotypic comparisons of susceptible delta-/- mice with delta-/- mice also deficient in selected pro-inflammatory cells and/or molecules by virtue either of treatment with cytokine antagonists or blocking antibodies, or of a second "knockout" genetic mutation 2. To characterize the genes expressed by "resting" DETC and DETC "activated" in vitro by serial analysis of gene expression (SAGE), validate such analyses by quantitative RT-PCR of DETC in various in vivo and in vitro activation states, and compare such gene expression patterns with those both of gut-associated gamma/delta+ and alpha/beta+ IELs, and of systemic CD8+ alpha/beta+ "naive" and "memory" T cells. 3. To investigate selected candidate DETC anti-inflammatory cytokines/effector molecules by reconstituting delta-/- recipients with fetal thymic DETC precursors rendered deficient in candidate anti-inflammatory molecules. 4. To utilize genome-wide microsatellite mapping to identify the genetic interval(s) controlling susceptibility/resistance to the spontaneous dermatitis that develops in some, but not other d-/- mice, followed by additional studies (development of congenic lines, differential expression analyses of genes contained within this interval) directed at definitive identification of the gene(s) that regulate cutaneous inflammation.