IN VIVO STUDIES OF VCAM-1 IN IMMUNITY

VCAM-1 免疫作用的体内研究

基本信息

批准号：
6893409
负责人：
Pandelakis Andreas Koni
金额：
$ 28.7万
依托单位：
AUGUSTA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-07-01 至 2007-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6893409
关键词：
apoptosis autoimmunity cell cell interaction cell differentiation dendritic cells genetically modified animals helper T lymphocyte laboratory mouse protein structure function tissue /cell culture vascular cell adhesion molecule

项目摘要

DESCRIPTION (provided by applicant): Vascular cell adhesion molecule-1 (VCAM-1) expression is increased on activated endothelium, where its ability to facilitate leukocyte adherence and subsequent transmigration into tissues is associated with several diseases. VCAM-1 is also expressed by antigen-presenting cells (e.g. macrophages, dendritic cells) where it might play a role in T cell response. Indeed, several in vitro studies by others show VCAM-1 to have an impact on the magnitude of T cell activation, and on activation-induced death of chronically-stimulated T cells. Also, others have shown anti VCAM-1 antibody to reduce disease without gross reduction of leukocyte infiltration of the target tissue. Thus, we hypothesize that VCAM-1 mediates critical interactions between dendritic cells and T cells during T cell differentiation and in processes of T cell regulation. We will test our hypothesis using 'VCAM-1 -deficient' mice. Others have attempted to further investigate the in vivo roles of VCAM-1 by generating conventional VCAM-I deficient mice. Unfortunately, these efforts met with limited success due to embryonic lethality resulting from VCAM-1-deficiency, revealing an essential requirement for VCAM-l in fetal placentation. This has been overcome here by generating VCAM-1 'knock-in' mice using the Cre recombinase/loxP system. These mice express normal levels of VCAM-1 but allow deletion of the VCAM-1 gene when intercrossed with a 'TIE2Cre' Cre recombinase transgene. These conditional 'VCAM-l-deficient' mice show virtually complete loss of VCAM-1 on hematopoietic cells (including dendritic cells) and endothelial cells. These mice will be employed in studies of T cell response to antigen and T cell peripheral self-tolerance. Thus, the specific aims here are to determine the role of VCAM-1 on dendritic cells with respect to CD4+ T helper cell development, T cell activation-induced cell death and T cell peripheral self-tolerance.

描述（申请人提供）：血管细胞粘附分子-1（VCAM-1）表达在活化的内皮上增加，其能力促进白细胞粘附并随后迁移到组织中与多种疾病有关。 VCAM-1也表达为抗原呈递细胞（例如巨噬细胞、树突状细胞）在T细胞反应中发挥作用。事实上，其他人的几项体外研究表明 VCAM-1 对 T 细胞激活的程度有影响，长期刺激的 T 细胞活化诱导死亡。另外，其他人也有显示抗 VCAM-1 抗体可减少疾病，但不会总体减少靶组织白细胞浸润。因此，我们假设 VCAM-1 在 T 过程中介导树突状细胞和 T 细胞之间的关键相互作用细胞分化和 T 细胞调节过程。我们将测试我们的使用“VCAM-1 缺陷”小鼠的假设。其他人则试图进一步通过生成常规 VCAM-I 研究 VCAM-1 的体内作用缺乏的老鼠。不幸的是，由于以下原因，这些努力收效有限： VCAM-1 缺陷导致胚胎致死，揭示了一个重要因素胎儿胎盘形成过程中对 VCAM-1 的需求。在这里已经克服了这个问题使用 Cre 重组酶/loxP 系统生成 VCAM-1“敲入”小鼠。这些小鼠表达正常水平的 VCAM-1，但在以下情况下允许删除 VCAM-1 基因：与“TIE2Cre”Cre 重组酶转基因杂交。这些有条件的 “VCAM-1 缺陷”小鼠的造血功能几乎完全丧失 VCAM-1 细胞（包括树突状细胞）和内皮细胞。这些老鼠将用于研究 T 细胞对抗原的反应和 T 细胞外周血自我宽容。因此，这里的具体目标是确定树突状细胞上的 VCAM-1 与 CD4+ T 辅助细胞发育、T 细胞活化诱导的细胞死亡和 T 细胞外周自身耐受。