Lymphocyte Homing Mechanisms in Normal & Inflamed Colon

描述（由申请人提供）： 虽然在白细胞在正常和炎症组织如皮肤和小肠中的运输领域已经做了大量的工作，但结肠相对未被探索。我们假设粘附分子表达的选择性组合识别优先归巢结肠的T细胞亚群。这一假说得到以下发现的支持：淋巴细胞亚群通过表达粘附分子的独特组合，表现出差异组织定位。此外，我们推测，改变粘附分子的表达，在一定程度上，解释了大量的T细胞流入结肠炎症过程中看到的。基于这些假设，我的建议的具体目标是： 目标1.表征慢性自发性小鼠结肠炎模型（角蛋白-8缺陷（K8 -/-）小鼠）中的炎症。在这个目标中，我们将表征与K8 -/-结肠炎相关的免疫应答。虽然K8是小肠和大肠中的主要角蛋白，但结肠是K8 -/-小鼠中炎症的主要靶点。我们发现，K8 -/-结肠炎与Th 2细胞因子的产生，这是服从抗生素治疗。 目标2.在正常和炎症条件下，使用K8 +/+和K8 -/-小鼠比较结肠和小肠固有层内T细胞和内皮细胞中的粘附和运输分子表达。在这里，我们将使用流式细胞术和免疫组织化学来确定差异粘附和运输分子表达的结肠内皮细胞和T细胞相比，其他组织，包括小肠。 目标3：确定目标2中鉴定的分子是否介导正常和炎症结肠中结肠固有层淋巴细胞的体内募集。在这里，我们将研究各种粘附分子的作用，通过进行过继细胞转移和使用阻断抗体在短期归巢测定。 K8 -/-小鼠是炎症性肠病（IBD）的独特模型，因为它代表了原发性上皮细胞缺陷，并为研究炎症和归巢结肠提供了大量细胞。这项拟议的研究应该提高我们对免疫细胞运输到结肠的理解，提供对可能的IBD致病机制的见解，并可能为IBD提供新的治疗靶点

DESCRIPTION (provided by applicant): Although extensive work has been done in the area of leukocyte trafficking in normal and inflamed tissues such as the skin and small intestine, the colon is relatively unexplored. We hypothesize that selective combinations of adhesion molecule expression identifies subsets of T cells that preferentially home to the colon. This hypothesis is supported by findings that subsets of lymphocytes, via their expression of unique combination of adhesion molecules, manifest differential tissue localization. Furthermore, we postulate that altered adhesion molecule expression, in part, explains the massive influx of T cells seen during colonic inflammation. Based on these hypotheses, the specific aims of my proposal are: Aim 1. Characterize the inflammation in a chronic spontaneous mouse colitis model, the keratin-8 deficient (K8 -/-) mice. In this aim we will characterize the immune response associated with the K8 -/- colitis. Although K8 is a major keratin in the small and large intestine, the colon is the primary target of inflammation in K8 -/- mice. We find that K8 -/- colitis is associated with Th2 cytokine production which is amenable to antibiotic treatment. Aim 2. Compare adhesion and trafficking molecule expression in T and endothelial cells within lamina propria of the colon and small intestine, under normal and inflammatory conditions, using K8 +/+ and K8 -/- mice. Here we will use flow cytometry and immunohistochemistry to determine differential adhesion and trafficking molecule expression by colon endothelial and T cells as compared with other tissues, including the small intestine. Aim 3. Determine whether molecules identified in aim 2 mediate recruitment of colon lamina propria lymphocytes in vivo in normal and inflamed colons. Here we will study the role of various adhesion molecules, by perfoming adoptive cell transfers and using blocking antibodies in short-term homing assays. The K8 -/- mouse is a unique model of inflammatory bowel disease (IBD) in that it represents a primary epithelial cell defect, and provides significant cell number to study inflammation and homing to the colon. The proposed study should improve our understanding of immune cell trafficking to the colon, offer insights into possible IBD pathogenic mechanisms, and potentially unfold new therapeutic targets to consider for IBD