IMMUNOBIOLOGY OF MURINE DENDRITIC EPIDERMAL T-CELLS

这项建议的目标是了解免疫生物学的相关性 O一种独特的T细胞亚群(称为树突状表皮T细胞，或DETC) 它们存在于所有正常小鼠的皮肤中，并了解它们的 (S)与正常人和疾病皮肤中存在的T细胞的关系。 DETC的独特特征(如V-Gamma5/V-Delta1+的同质性 T细胞受体(TCR)，成年小鼠对皮肤的明显限制， 以及识别在应激的表皮细胞上表达的配体的能力)， 导致了一种假设，即它们在皮肤中扮演着不同的角色 免疫监测和/或免疫调节；假设(但未经证实) 作用包括对细胞内感染的早期反应，消除 改变/应激细胞，下调由以下途径介导的反应 传统的TCRα-β细胞，甚至可能启动 自身免疫力。该方案的具体目的包括：1)体内 对DETC在体内潜在相关生物学作用的研究 皮肤免疫和/或免疫病理学 选择性缺失V-Gamma5+DETC的重组小鼠 这种DETC缺陷小鼠在几个模型系统中，包括诱导和 皮肤肿瘤的生长、过敏性接触性皮炎和实验性 皮肤自身免疫性疾病。2)影响因素的定义 DETC在皮肤中的定位/增殖。战略包括 尝试用类DETC重建DETC缺陷小鼠的皮肤 新生肝脏细胞及生长期毛发作用的研究(S) 用DETC密度/异质性分析卵泡在这些过程中的作用 不同毛发突变小鼠的皮肤和荧光素定位- 标记的胎儿胸腺细胞。3)表征激活DETC的配体 以及参与这种激活的分子。战略包括 对广泛的正常和转化的细胞/系进行分析 各种组织刺激DETC增殖和 体外分泌IL-2，使用α-热休克蛋白单抗或单抗 由DETC表达的各种黏附/辅助分子(如CD45，CD8， LFA-1，CD28)试图阻断这种反应，并准备一种 针对DETC V-Gamma5/V-Delta1+TCR配体的单抗 应激表皮细胞以提纯相关刺激物 分子(S)。4)DETC的功能异构性分析。 策略包括检测辅助分子在DETC上的表达 不同的激活状态(新分离的与保持的品系/克隆 在不同的培养条件下)，并将这些模式与DETC相关联 增殖、淋巴因子分泌和细胞毒谱以及 检测新鲜分离的和细胞毒性的淋巴因子和细胞毒谱 培养的正常和IL-2缺陷小鼠的DETC(同源重组体 或HSV-胸苷激酶转基因)与IL-2等细胞因子培养， IL-4或IL-7。这样的研究应该会促进对伽马三角洲的理解 生理和病理条件下的细胞/皮肤相互作用 老鼠和人类都是如此。

The goals of this proposal are to understand the immunobiologic relevance o a unique subset of T cells (called dendritic epidermal T cells, or DETC) which populate the skin of all normal mice, and to understand their relationship(s) to the T cells present in normal and diseased human skin. The unique features of DETC (e.g., homogeneity of their V-gamma5/V-delta1+ T cell receptors (TCRs), apparent restriction in adult mice to the skin, and capacity to recognize a ligand expressed on stressed epidermal cells), have led to the hypothesis that they play distinctive roles in cutaneous immune surveillance and/or immunoregulation; postulated (but unproven) roles include early responses to intracellular infection, elimination of altered/stressed cells, down-regulation of responses mediated by conventional TCRalpha-beta cells, and perhaps even initiation of autoimmunity. The specific aims of this proposal include: 1) In vivo examination of such potentially relevant biologic roles of DETC in cutaneous immunity and/or immunopathology by developing homologous recombinant mice selectively deficient in V-gamma5+ DETC and then testing such DETC-deficient mice in several model systems, including induction and growth of skin tumors, allergic contact dermatitis, and experimental cutaneous autoimmune disease. 2) Definition of factors affecting the localization/proliferation of DETC in the skin. Strategies include attempts to reconstitute the skin of DETC-deficient mice with DETC-like cells from newborn liver, and studies of the role(s) of anagen hair follicles in these processes by analysis of DETC density/heterogeneity in the skin of various hair mutant mice and by localization of fluorescein- labeled fetal thymocytes. 3) Characterize the ligands which activate DETC and the molecules involved in such activation. Strategies include analysis of a broad range of normal and transformed cells/lines from various tissues for their abilities to stimulate DETC proliferation and IL-2 secretion in vitro, use of alpha-heat shock protein Abs or Abs to various adhesion/accessory molecules expressed by DETC (such as CD45, CD8, LFA-1, CD28) to try to block such responses, and preparation of a monoclonal Ab directed against the DETC V-gamma5/V-delta1+ TCR ligand on stressed epidermal cells in order to purify the relevant stimulatory molecule(s). 4) Analysis of the functional heterogeneity of DETC. Strategies include examining accessory molecule expression on DETC in different activation states (freshly isolated vs lines/clones maintained under distinct culture condition) and correlating these patterns with DETC proliferation, lymphokine secretion and cytotoxicity profiles, as well as examining the lymphokine and cytotoxicity profiles of freshly isolated and cultured DETC from normal and IL-2-deficient mice (homologous recombinants or HSV-thymidine kinase transgenics) cultured with such cytokines as IL-2, IL-4 or IL-7. Such studies should advance understanding of gamma-delta cell/skin interactions under physiologic and pathologic circumstances in mice and in man.