Lymphocyte Function Associated Antigens

淋巴细胞功能相关抗原

基本信息

批准号：
9527750
负责人：
TIMOTHY A SPRINGER
金额：
$ 58.17万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
1981
资助国家：
美国
起止时间：
1981-07-01 至 2019-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9527750
关键词：
3-Dimensional Actins Address Adhesions Adhesiveness Adhesives Affect Affinity Agonist Anti-Inflammatory Agents Antigens Autoimmune Diseases Binding Binding Sites Blood Circulation Cell Adhesion Cell Adhesion Molecules Cell Communication Cell membrane Cell surface Cells Complex Crystallization Cytoplasmic Tail Cytoskeleton Development Disease Endothelial Cells Extracellular Domain Family Fluorescence Anisotropy Fluorescence Microscopy Fluorescence Polarization Fluorescence Resonance Energy Transfer Grant Health Hereditary Disease Hybrids ICAM1 gene ICAM2 gene ICAM3 gene Imaging Techniques Immune response Infection Inflammation Integrin beta Chains Integrins Intercellular Adhesion Molecules Lateral Leukocytes Ligand Binding Ligands Link Location Lymphocyte Lymphocyte Function Lymphoid Measurement Measures Mediating Methods Microbe Microscopy Modeling Molecular Molecular Conformation Motion Mutation Organ Patients Physiological Polarization Microscopy Positioning Attribute Pyrrolidonecarboxylic Acid Regulation Research Resolution Rhinovirus Role Signal Transduction Site Structure Techniques Testing Therapeutic Thermodynamics Traction Transplantation Work cell motility dimer drug development experimental study extracellular flexibility improved inhibitor/antagonist innovation interest lymphocyte function associated antigen member migration public health relevance sensor single molecule small molecule therapeutic target transmission process tumor

项目摘要

DESCRIPTION (provided by applicant): Lymphocyte function-associated (LFA) molecules and intercellular adhesion molecules (ICAMs) are important both in antigen-specific interactions in immune responses and in interactions with endothelial cells during leukocyte localization in inflammation. LFA1 is an αβ heterodimer and a member of the integrin family. It binds ICAMS, including ICAM1, ICAM2, ICAM3, and ICAM5 that are members of the Ig superfamily (IgSF). The physiologic importance of these molecules is demonstrated by effect of deficiency of LFA-1 in an inherited disease, LAD; and previous approval of an antagonist of LFA-1 to treat autoimmune disease in patients. Studies of the function of these molecules in health and disease, the regulation of adhesiveness through them, and the structure of their interaction sites is of great importance, and will lead to the development of further anti-inflammatory agents. LFA-1 transduces signals bidirectionally across the plasma membrane that regulate binding to extracellular ligands and intracellular signaling. The conformational changes in the extracellular and cytoplasmic domains and the mechanisms that couple them are of great interest. We will use crystal, SAXS, and EM structures to study how conformational change is relayed in the LFA-1 ectodomain to the headpiece, and between the hybrid, βI, and αI domains to activate binding of ICAM to the LFA-1 αI domain. Structures of allosteric small molecule and Fab antagonists and agonists bound to LFA-1, together with measurements of how conformational equilibria affect affinity, will provide information on affinity regulation and advance drug development. In cells, cytoplasmic domain regions will be tested for effect on LFA-1 affinity and LFA-1- dependent cell migration. How is integrin activation coordinated with the cytoskeleton to regulate directed lymphocyte migration? We hypothesize that inherent in LFA1 structural transitions is a mechanism for linking the high affinity, open conformation to engagement with ICAM1 and the cytoskeleton. We will test the innovative concept that a lateral pull on the integrin β cytoplasmic domain by the cytoskeleton, resisted by ICAM, is important in maturation of LFA-1 to high affinity. Multiple fluorescent microscopy techniques will examine the link between LFA-1 structure and function in migration of intact cells. These include measurements on single molecules and adhesive foci that correlate LFA-1 activation with actin cytoskeleton and cellular motion, dynamic FRET to measure integrin force transmission and two fluorescence polarization techniques to measure effects of the cytoskeleton on the dynamics and alignment of the LFA-1 headpiece. Uniting molecular and cellular studies, we will determine the orientation of LFA1 as it provides cellular traction by binding to ICAM1 and the cytoskeleton. The orientation of LFA-1 will be determined relative to actin retrograde flow, to test a key tenet of te traction (lateral) force model of integrin activation.

描述（由申请人提供）：淋巴细胞功能相关 (LFA) 分子和细胞间粘附分子 (ICAM) 在免疫反应中的抗原特异性相互作用以及炎症中白细胞定位期间与内皮细胞的相互作用中都很重要。它是整合素家族的成员，包括 ICAM1、ICAM2、ICAM3 和 ICAM5（Ig 成员）。 LFA-1 缺陷对 LAD 的影响以及先前批准的 LFA-1 拮抗剂用于治疗患者自身免疫性疾病的功能研究证明了这些分子的生理重要性。这些分子在健康和疾病中、通过它们调节粘附性及其相互作用位点的结构非常重要，并将导致 LFA-1 跨质膜双向转导信号的进一步开发。调节结合细胞外和细胞质结构域的构象变化以及它们的耦合机制非常令人感兴趣，我们将使用晶体、SAXS 和 EM 结构来研究构象变化如何在 LFA-1 胞外域中传递。头部，以及杂合体、βI 和 αI 结构域之间，以激活 ICAM 与 LFA-1 αI 结构域的结合。 LFA-1 与构象平衡如何影响亲和力的测量一起，将提供有关亲和力调节和推进药物开发的信息。在细胞中，将测试细胞质结构域区域对 LFA-1 亲和力和 LFA-1 依赖性细胞迁移的影响。整合素激活如何与细胞骨架协调来调节定向淋巴细胞迁移？我们勇敢地承认，LFA1 结构转变中固有的是一种将高亲和力、开放构象与 ICAM1 和细胞骨架连接起来的机制。测试创新概念，即细胞骨架对整合素 β 细胞质结构域的横向拉力（受 ICAM 抵抗）对于 LFA-1 成熟至高亲和力非常重要。多种荧光显微镜技术将检查 LFA-1 结构和功能之间的联系。这些包括对将 LFA-1 激活与肌动蛋白细胞骨架和细胞运动相关的单分子和粘附灶进行测量、测量整合素力传递的动态 FRET 以及两种荧光偏振技术为了测量细胞骨架对 LFA-1 头件的动力学和排列的影响，我们将结合分子和细胞研究来确定 LFA1 的方向，因为它通过与 ICAM1 和细胞骨架结合来提供细胞牵引力。将相对于肌动蛋白逆行流进行确定，以测试整合素激活的牵引（横向）力模型的关键原则。