MECNHANISMS OF CELL ADHESION AND TRAFFICKING IN EXPERIMENTAL ILEITIS

实验性回肠炎中细胞粘附和运输的机制

• 批准号: 7491474
• 负责人: Klaus F. Ley
• 金额: $ 19.22万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7491474
• 关键词: Address; Adhesions; Adoptive Transfer; Age; Antibodies; Area; B-Lymphocytes; Bone Marrow Transplantation; CD4 Positive T Lymphocytes; Cell Adhesion; Cell Adhesion Molecules; Cells; Crohn' s disease; Data; Development; Disease; Distal part of ileum; Endothelial Cells; Funding; Head; Home environment; Ileitis; Immunodeficient Mouse; Inflammation; Inflammatory; Integrins; Intercellular adhesion molecule 1; Intestines; L-Selectin; Lamina Propria; Leukocytes; Ligands; Lymphocyte; Lymphoid Cell; Mediating; Memory; Messenger RNA; Modeling; Monoclonal Antibodies; Mus; Myelogenous; Myeloid Cells; Nature; Onset of illness; P-Selectin; P-selectin ligand protein; PNAd; Pathway interactions; Patients; Phenotype; Play; Prevention; Progress Reports; Proteins; Research Design; Reverse Transcriptase Polymerase Chain Reaction; Role; SCID Mice; Severities; Severity of illness; Sorting - Cell Movement; Source; Speed; Submucosa; Surface; T memory cell; T-Lymphocyte; Testing; Therapeutic Studies; Thinking; Time; Tissues; Vascular Cell Adhesion Molecule-1; Week; base; congenic; design; ileum; laser capture microdissection; mouse model; mucosal addressin cell adhesion molecule-1; neutrophil; novel; null mutation; promoter; trafficking; venule

Project 4, headed by Dr. Klaus Ley, studies the mechanisms of intestinal T cell adhesion and inflammatory cell trafficking in SAMP1/YitFc (SAMP) mice. The original project was designed to test the hypothesis that: 1) SAMP mice express adhesion molecules relevant to the trafficking of T cells, neutrophils, and other leukocytes, 2) leukocytes and/or endothelial adhesion molecules are required for the development of ileitis in recipients of CD4+ T cells transferred from SAMP mice, and 3) CD4+ T cells use specific adhesion molecules to home to the terminal ileum of SAMP mice and cause disease. In the past four years, important progress has been made with respect to the discovery that the endothelial adhesion molecules VCAM-1, ICAM-1, MAdCAM-1, P-selectin, and PNAd are significantly upregulated in inflamed areas of the SAMP ileum. Therapeutic studies have shown that blocking alpha 4 integrins, a combination of VCAM-1 and ICAM-1, or a combination of MAdCAM-1 and L-selectin significantly ameliorates disease severity in the adoptive transfer model. The finding that L-selectin is important in promoting inflammation represented a novel and unexpected observation regarding this molecule, since L-selectin is thought to be expressed on naive T cells. However, L-selectin inhibition may limit the recruitment of inflammatory myeloid cells, as well as naive, memory, and regulatory T cells, or a combination thereof. In addition, we discovered that B cells play a pathogenic role in the SAMP model of ileitis. For the next funding period, Project 4 will focus on L-selectin and one of its ligands, PSGL-1, based on two recent discoveries: 1) demonstration of the importance of L-selectin in mediating ileitis, and 2) preliminary evidence that PSGL-1 is expressed in endothelial cells of lamina propria microvessels in the terminal ileum. Based on these discoveries, this project will first test whether the L-selectin ligand PSGL-1 is expressed in inflamed endothelial cells of the ileal lamina propria and submucosa using immunostaining, laser capture microdissection, and real-time RT-PCR. The functional role of the PSGL-1/L-selectin pathway of adhesion will be studied using monoclonal antibodies to block PSGL-1, as well as by crossing SAMP mice with existing PSGL-1 deficient mice using speed congenics. Finally, the nature of L-selectin expressing cells that contribute to ileitis severity in the SAMP adoptive transfer model will be studied. These studies are designed to understand the mechanisms of trafficking of pathogenic, naive and regulatory lymphocytes in the inflamed ileum of SAMP mice and to provide a rational basis for ameliorating disease severity by single or combined blockade of intestinal-specific adhesion molecules in patients with Crohn's disease.

项目 4 由 Klaus Ley 博士领导，研究 SAMP1/YitFc (SAMP) 小鼠肠道 T 细胞粘附和炎症细胞运输的机制。最初的项目旨在测试以下假设：1) SAMP 小鼠表达与 T 细胞、中性粒细胞和其他白细胞运输相关的粘附分子，2) 受体中发生回肠炎需要白细胞和/或内皮粘附分子从 SAMP 小鼠转移的 CD4+ T 细胞，3) CD4+ T 细胞使用特定的粘附分子归巢到 SAMP 小鼠的回肠末端并引起疾病。在过去的四年里，我们发现内皮粘附分子 VCAM-1、ICAM-1、MAdCAM-1、P-选择素和 PNAd 在 SAMP 回肠炎症区域显着上调，取得了重要进展。治疗研究表明，阻断 α4 整合素、VCAM-1 和 ICAM-1 的组合或 MAdCAM-1 和 L-选择素的组合可显着改善过继转移模型中的疾病严重程度。 L-选择素在促进炎症方面很重要的发现代表了关于该分子的新颖且意想不到的观察，因为L-选择素被认为在初始T细胞上表达。然而，L-选择素抑制可能会限制炎症性骨髓细胞以及初始、记忆和调节性 T 细胞或其组合的募集。此外，我们发现B细胞在回肠炎的SAMP模型中发挥致病作用。在下一个资助期内，项目 4 将重点关注 L-选择素及其配体之一 PSGL-1，基于最近的两项发现：1) 证明 L-选择素的重要性 介导回肠炎，2) 初步证据表明 PSGL-1 在内皮细胞中表达 回肠末端的固有层微血管。基于这些发现，该项目将首先使用免疫染色、激光捕获显微切割和实时RT-PCR来测试L-选择素配体PSGL-1是否在回肠固有层和粘膜下层的发炎内皮细胞中表达。 PSGL-1/L-选择素粘附途径的功能作用将使用单克隆抗体阻断 PSGL-1，以及使用速度同源性将 SAMP 小鼠与现有 PSGL-1 缺陷小鼠杂交来研究。最后，将研究 SAMP 过继转移模型中导致回肠炎严重程度的 L-选择素表达细胞的性质。这些研究旨在了解 SAMP 小鼠发炎回肠中致病性、幼稚性和调节性淋巴细胞的运输机制，并提供合理的治疗方法。 通过单一或联合阻断克罗恩病患者肠道特异性粘附分子来改善疾病严重程度的基础。