Very Late Antigen Integrin Activity on T Cells

T 细胞上的极晚期抗原整合素活性

基本信息

批准号：
7193444
负责人：
YOJI SHIMIZU
金额：
$ 31.89万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
1991
资助国家：
美国
起止时间：
1991-04-01 至 2011-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7193444
关键词：
Adhesions Adoptive Transfer Amino Acids Animals Antigen-Presenting Cells Antigens CD18 Antigens Cell Adhesion Cell physiology Cell surface Cells Complex Couples Cytoplasmic Tail Development Disruption Exons Extracellular Matrix Extracellular Matrix Proteins Family Funding Gene Targeting Gene Transfer Techniques Guanine Nucleotide-Releasing Factor 2 Immune response Immune system In Vitro Integrins Laboratories Localized Mediating Membrane Molecular Conformation Monomeric GTP-Binding Proteins Mus Numbers Phorbol Esters Phosphotransferases Play Process Protein Kinase Protein Kinase C Proteins RNA Interference Receptor Signaling Regulation Research Personnel Role Serine Signal Pathway Signal Transduction System T-Cell Activation T-Cell Receptor T-Lymphocyte Tail Technology Testing Tetradecanoylphorbol Acetate Threonine Tissues Transgenic Mice Transgenic Organisms adapter protein adenoviral-mediated adhesion receptor antigen challenge base in vivo member novel pathogen programs protein function protein kinase C kinase receptor response trafficking

项目摘要

DESCRIPTION (provided by applicant): Integrin adhesion receptors play a vital role in cell function and development by mediating the adhesion of cells to other cells and to extracellular matrix proteins. In the immune system, the functional activity of integrins expressed on T lymphocytes is dynamically regulated by the activation state of the T cell in order to promote transient periods of adhesion that facilitate T cell trafficking and antigen recognition in tissue. Stimulation of the antigen-specific CD3/T cell receptor (TCP) complex initiates a signaling cascade that results in a rapid increase in the functional activity of beta l and beta 2 integrins without increases in integrin levels on the cell surface. TCR-mediated integrin activation can be mimicked by phorbol esters such as PMA, implicating effectors downstream of protein kinase C (PKC) in this process. During the prior funding period, we identified a novel adapter protein function for the PKC effector protein kinase D1 (PKD1) in PMA- and TCR-mediated enhancement of beta l integrin function that is associated with increased beta l integrin clustering and activation of the small GTPase Rap1. We propose that the carboxy-terminal end of the beta l integrin cytoplasmic domain regulates integrin function in response to T cell activation by nucleating the formation of a membrane-localized complex consisting of PKD1, Rap1 and the Rap1 guanine nucleotide exchange factor C3G that controls Rap1 activation and subsequent integrin clustering. We propose the use of novel in vitro cell systems and genetically modified mice in order to test this hypothesis and its relevance to T cell function during immune responses in intact animals. In Aim 1, we will define the structural basis for interactions between the beta l integrin cytoplasmic domain and the PKD1/Rap1/C3G complex and determine if the beta l integrin tail is sufficient to control Rap1 activity. In Aim 2, we will use conditional gene targeting and adoptive transfer approaches to define the function of beta l integrin expression in controlling integrin- dependent responses of T cells to antigen challenge in mice. We will specifically determine if beta2 integrin function is dependent on expression of a beta l integrin subunit that couples effectively to PKD1 and Rap1. In Aim 3, we will use RNA interference and adenoviral-mediated gene transfer techniques to elucidate the function of PKD1 in regulating integrin function in vitro and T cell activation responses to antigen in vivo. Together, these studies will define a novel function for both PKD1 and the beta l integrin cytoplasmic domain in regulating integrin function in T cells and will enhance our ability to develop novel therapies that can specifically modulate T cell immune responses.

描述（由申请人提供）：整联蛋白粘附受体通过介导细胞与其他细胞和细胞外基质蛋白的粘附，在细胞功能和发育中发挥重要作用。在免疫系统中，T 淋巴细胞上表达的整合素的功能活性由 T 细胞的激活状态动态调节，以促进短暂的粘附期，从而促进 T 细胞在组织中的运输和抗原识别。刺激抗原特异性 CD3/T 细胞受体 (TCP) 复合物会引发信号级联，导致 β1 和 β2 整合素的功能活性快速增加，而细胞表面的整合素水平不会增加。 TCR 介导的整合素激活可以通过佛波酯（例如 PMA）来模拟，这表明该过程中存在蛋白激酶 C (PKC) 下游的效应子。在之前的资助期间，我们在 PMA 和 TCR 介导的 β l 整合素功能增强中发现了 PKC 效应蛋白激酶 D1 (PKD1) 的一种新的接头蛋白功能，该功能与 β l 整合素聚集的增加和小GTP 酶 Rap1。我们提出，βl 整合素胞质结构域的羧基末端通过成核形成由 PKD1、Rap1 和控制 Rap1 的 Rap1 鸟嘌呤核苷酸交换因子 C3G 组成的膜定位复合物来调节整合素功能，以响应 T 细胞激活激活和随后的整合素聚类。我们建议使用新型体外细胞系统和转基因小鼠来测试这一假设及其与完整动物免疫反应期间 T 细胞功能的相关性。在目标 1 中，我们将定义 βl 整合素胞质结构域与 PKD1/Rap1/C3G 复合物之间相互作用的结构基础，并确定 βl 整合素尾部是否足以控制 Rap1 活性。在目标 2 中，我们将使用条件基因靶向和过继转移方法来定义 β1 整合素表达在控制小鼠 T 细胞对抗原攻击的整合素依赖性反应中的功能。我们将具体确定 beta2 整合素功能是否依赖于与 PKD1 和 Rap1 有效偶联的 β1 整合素亚基的表达。在目标3中，我们将利用RNA干扰和腺病毒介导的基因转移技术来阐明PKD1在体外调节整合素功能和体内T细胞激活对抗原反应的功能。总之，这些研究将定义 PKD1 和 β1 整合素胞质结构域在调节 T 细胞整合素功能中的新功能，并将增强我们开发可特异性调节 T 细胞免疫反应的新疗法的能力。