CCR9 and TECK in Intestinal Lymphocyte Trafficking

描述：(申请者摘要)：趋化因子与 淋巴细胞转运和微环境定位的控制 正常的淋巴细胞再循环，以及在免疫反应期间。这项建议 重点了解新的趋化因子受体CCR9及其受体的作用 肠道免疫中的趋化配体Teck。调查员已经 显示CCR9由循环A4J37+的离散子集表示 “肠道”记忆T细胞，以及几乎所有固有层和 小肠上皮内淋巴细胞；其配体Teck 由小肠上皮细胞优先表达。这里, 研究人员将探索这种受体-配体对的假设 在靶向小肠免疫细胞方面起着基础性作用，有助于 将粘膜与系统免疫反应方式隔离(并可能 甚至是来自大肠免疫反应的小病毒)。1)表型和 人类CCR9+淋巴细胞亚群的功能特性将被表征 通过流式细胞仪和细胞因子分析，以及CCR9和Teck参与 小鼠肠道淋巴细胞对全身淋巴细胞的趋化反应 在Transwell趋化试验中进行评估。2)Teck mRNA的细胞定位 表达将通过原位杂交来定义，并且分布 TECK在蛋白质水平上将通过免疫组织化学在 肠道和其他组织。3)调查员应确定CCR9+ 细胞由循环记忆和/或肠道回忆效应细胞组成 抗原，利用对轮状病毒的免疫反应，很好地表征了小分子 肠道病原体，作为模型。T细胞记忆反应的体外分析， B细胞抗原结合试验和小鼠体内免疫试验， 将用于表征轮状病毒特异性B和T淋巴细胞并评估 CCR9的表达。4)CCR9和TECK在生理学中的作用 淋巴细胞向肠道的转运将通过原位检测进行评估 视频显微镜，重点是他们假想的跨内皮细胞参与 渗出症。拟议的研究将批判性地界定CCR9的重要性 及其配体Teck使淋巴细胞归巢至小肠板 它们在分离肠道免疫反应中的作用，以及它们的 有可能成为炎症性肠病的治疗靶点。

DESCRIPTION: (Applicant's Abstract): Chemokines have been implicated in the control of lymphocyte trafficking and microenvironmental positioning during normal lymphocyte recirculation, and during immune responses. This proposal focuses on understanding the role of the novel chemokine receptor CCR9 and its chemoattractant ligand TECK in the intestinal immunity. The investigator has shown that CCR9 is expressed by a discrete subset of circulating a4J37 + "intestinal" memory T cells, and by almost all lamina propria and intraepithelial lymphocytes in the small intestines; and that its ligand TECK is preferentially expressed by epithelial cells of the small intestines. Here, the investigator shall explore the hypothesis that this receptor-ligand pair plays a fundamental role in targeting small intestinal immune cells, helping to segregate mucosal from systemic immune response modalities (and potentially even small from large intestinal immune responses). 1) The phenotype and functional properties of CCR9+ lymphocyte subsets in man will be characterized by flow cytometric and cytokine assays; and the involvement of CCR9 and TECK in the chemotactic responses of intestinal vs. systemic lymphocytes in mice will be assessed in transwell chemotaxis assays. 2) The cellular sites of TECK mRNA expression will be defined by in situ hybridization, and the distribution of TECK at the protein level will be explored by immunohistochemistry in intestines and other tissues. 3) The investigator shall determine whether CCR9+ cells comprise circulating memory and/or effector cells for intestinal recall antigens, using the immune response to rotavirus, a well characterized small intestinal pathogen, as a model. In vitro assays of T cell memory responses, antigen-binding assays of B cells, and in vivo assays of immunity in the mouse, will be used to characterize rotavirus-specific B and T lymphocytes and assess their expression of CCR9. 4) Finally, the role of CCR9 and TECK in physiologic lymphocyte trafficking to the intestines will be evaluated by in situ videomicroscopy, focusing on their hypothesized involvement in transendothelial diapedesis. The studies proposed will define critically the importance of CCR9 and its ligand TECK for homing of lymphocytes to the small intestinal lamina propria, their role in segregating intestinal immune responses, and their potential as therapeutic targets in inflammatory bowel diseases.