Role of L-selectin and its Ligands in Chronic Murine Ileitis

L-选择素及其配体在小鼠慢性回肠炎中的作用

基本信息

批准号：
7493974
负责人：
Jesus Rivera-Nieves
金额：
$ 13.63万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-09-01 至 2009-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7493974
关键词：
Address Adhesions Adhesives Adoptive Transfer Animal Model Antibodies Appearance Arthritis Asses Attenuated Binding Biological Assay Biological Response Modifier Therapy Breeding Budgets C-Type Lectins CCL21 gene CD4 Positive T Lymphocytes Canada Cell Adhesion Molecules Cells Chronic Collaborations Colon Colorado Crohn&apos s disease Data Deposition Development Disease Distal part of ileum Enzymes Epitopes Figs - dietary Funding Genotype Genus Cola Glycoproteins Goals Hematopoietic High Endothelial Venule Homing Human Ileitis Immunohistochemistry Inbred AKR Mice Inflammation Inflammatory Inflammatory Bowel Diseases Institutes Integrin alpha4beta1 Intestines Journals L-Selectin Label Laboratories Lamina Propria Large Intestine Leukocyte Rolling Leukocytes Ligands Light Localized Lymphocyte Lymphocyte Subset Lymphoid Lymphoid Follicle Maintenance Manuscripts Mediating Medicine Microscopy Modeling Modification Molecular Molecular Target Mouse Strains Mus Organ P-selectin ligand protein PNAd Pathogenesis Pathway interactions Peripheral Play Process Publishing Rattus Research Design Reverse Transcriptase Polymerase Chain Reaction Rheumatoid Arthritis Role SCID Mice Severities Signal Transduction Site Small Intestines Source Submucosa T memory cell T-Lymphocyte T-Lymphocyte Subsets Techniques Terminal Ileitis Testing Therapeutic Effect Therapeutic Studies Time Tumor Necrosis Factor-alpha Ulcerative Colitis Universities Virginia Work base chemokine chemokine receptor concept human TNF protein human disease integrin alpha4beta7 intestinal villi intravital microscopy lipoprotein lipase migration mouse model mucosal addressin cell adhesion molecule-1 novel research study sulfotransferase therapeutic target trafficking

项目摘要

DESCRIPTION (provided by applicant): T cells are central to the pathogenesis of the inflammatory bowel diseases, which include ulcerative colitis (UC) and Crohn's disease (CD). While UC involves strictly the large intestine; CD involves predominantly the small bowel. Therefore the recirculating lymphocyte pool must express a defined repertoire of adhesion molecules and chemokine receptors that allows recognition of these 2 intestinal segments. Our understanding of the specific molecules that mediate differential trafficking to small or large bowels is limited, in part due to the lack of animal models that develop inflammation specifically in the small intestine. Our long-term goal is to dissect the adhesive pathways responsible for lymphocyte trafficking to the chronically inflamed small bowel using a novel murine model (i.e. SAMP1/Yit). Our specific hypothesis is that chronic inflammation induces inappropriate expression of adhesion molecules, supporting continuous dysregulated recruitment of pathogenic T cells to the small bowel. Our recent findings shed light on 2 concepts that appear pivotal to our understanding of small intestinal trafficking. First, effector T cells coexpress not only the gut-homing integrin alpha4beta7, abut also the peripheral homing integrin alpha4beta1 and L-selectin. These L- selectin(positive) cells are important producers of TNF-alpha and targeted immunoblockade of this molecule attenuated ileitis. Based on these observations our experimental focus is on L-selectin-mediated lymphocyte recruitment to the small bowel. Our specific aims will: 1. Determine whether effector CD4+ T cells re-express L-selectin to recirculate to the small intestinal lamina propria (LP). We will (i) assess whether CD4+ T cells reexpress L-selectin using fluorescent cell homing assays. (ii) Functionally assess the capacity of L-selectin(negative) compared to L-selectin(positive) T cells to adoptively transfer ileitis via T cell transfer and histological assessment of the severity of ileitis. 2. Define the small intestinal endothelial ligands responsible for the therapeutic effect of L-selectin immunoblockade in chronic murine ileitis. We will perform therapeutic studies designed to assess the contributions of i) MAdCAM-1and ii) PNAd as specific endothelial ligands for L-selectin in the chronically inflamed small bowel. 3. Identify the cellular and molecular mechanisms responsible for the efficacy of L-selectin/MAdCAM-1 blockade as therapeutic targets in chronic ileitis. We will (i) define the role of L-selectin, alpha4beta1, alpha4beta7 integrins and MAdCAM-1 along the adhesion cascade using intravital microscopy. ii) Determine the time course of HEC-6 sulfotransferase induction through adoptive T cell transfer, Immunohistochemistry and real time RT-PCR. Given the similarities between the small intestinal-specific disease of the SAMP1/Yit model and human CD, our studies may shed light on the mechanisms that determine trafficking of effector T cells specifically to the small bowel and potentially identify new molecular targets for the treatment of CD.

描述（由申请人提供）： T细胞是炎症性肠病的发病机理的核心，包括溃疡性结肠炎（UC）和克罗恩病（CD）。 UC严格涉及大肠； CD主要涉及小肠。因此，循环淋巴细胞池必须表达粘附分子和趋化因子受体的定义曲目，该曲目允许识别这两个肠片段。我们对介导差异运输到小肠的特定分子的理解受到限制，部分原因是缺乏动物模型在小肠中特别发炎。我们的长期目标是使用新型的鼠模型（即SAMP1/YIT）剖析导致淋巴细胞运输的粘合剂途径。我们的具体假设是，慢性炎症会诱导粘附分子的不当表达，从而支持致病性T细胞对小肠的连续失调募集。我们最近的发现阐明了两个对我们对小肠贩运的理解至关重要的概念。首先，效应T细胞不仅共表达了肠道含素整合素α4Beta7，还可以共表达外周的归巢整合素alpha4beta1和l-链蛋白。这些L-选择蛋白（阳性）细胞是TNF-α的重要产生者，并且该分子的靶向免疫阻滞减弱了。基于这些观察结果，我们的实验重点是L-选择素介导的淋巴细胞募集到小肠。我们的具体目标将： 1。确定效应CD4+ T细胞是否重新表达L-选择素以再循环到小肠道层（LP）。我们将（i）使用荧光细胞归巢测定法评估CD4+ T细胞是否重新表达L-选择素。（ii）与L-选择蛋白（阳性）T细胞相比，L-选择素（阴性）的能力通过T细胞转移和对回肠炎的严重程度的组织学评估相比。 2。定义负责L-选择蛋白免疫阻滞在慢性鼠回肠炎中的治疗作用的小肠内皮配体。我们将进行旨在评估i）madcam-1和ii）pNAD的贡献的治疗研究，作为在长期发炎的小肠中作为L-选择素的特定内皮配体。 3。确定负责L-选择蛋白/MADCAM-1阻断功效的细胞和分子机制作为慢性回肠炎的治疗靶标。我们将（i）使用弹性显微镜沿粘附级联反应来定义L-选择素，alpha4beta1，alpha4beta1和madcam-1的作用。 ii）确定通过过继的T细胞转移，免疫组织化学和实时RT-PCR来确定HEC-6硫代转移酶诱导的时间过程。鉴于SAMP1/YIT模型的小肠特异性疾病与人CD之间的相似性，我们的研究可能阐明了确定效应T细胞专门针对小肠的运输的机制，并有可能识别出新的分子靶标，以治疗用于治疗的治疗光盘。