Dynamic Strengths of Leukocyte Adhesion Bonds

白细胞粘附键的动态强度

• 批准号: 7195443
• 负责人: EVAN A EVANS
• 金额: $ 31.7万
• 依托单位: BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2011-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7195443
• 关键词: Adhesions; Adhesives; Affinity; Agonist; Amino Acid Sequence; Avidity; Back; Binding Sites; Biochemical Pathway; Cell membrane; Cell surface; Cell-Matrix Junction; Cells; Cellular Structures; Chemicals; Complex; Condition; Cytokine Activation; Cytoplasmic Tail; Cytoskeleton; Dependence; Dissociation; Divalent Cations; Emigrations; Event; F-Actin; Failure; Family; IL8 gene; Immunoglobulins; Individual; Inflammation; Injury; Integrin Binding; Integrin alpha4beta1; Integrins; Intercellular adhesion molecule 1; Kinetics; L-Selectin; Leukocytes; Ligands; Link; Measures; Mechanics; Mediating; Membrane; Methods; Microspheres; Modification; Molecular; Mucins; Mutation; Object Attachment; P-selectin ligand protein; Pathway interactions; Peptide Sequence Determination; Play; Process; Protein Family; Proteins; Rate; Recombinants; Reinforcing Factor; Research; Research Design; Research Personnel; Resolution; Role; Rupture; Selectins; Signal Transduction; Site; Stimulus; Stress; Tail; Talin; Techniques; Testing; Tissues; Vascular Cell Adhesion Molecule-1; chemokine; computerized data processing; cytokine; design; established cell line; ezrin; feeding; formyl peptide; in vivo; innovation; insight; intercellular cell adhesion molecule; migration; moesin; nanoscale; novel; novel strategies; optical traps; paxillin; programs; radixin protein; receptor; response; single molecule; trafficking

DESCRIPTION (provided by applicant): Our long-term objective is to develop a detailed biophysical understanding of leukocyte adhesion at the molecular level, relating adhesive bond strength to chemical interactions and establishing how adhesive bond stress is transmitted through the cell membrane to the interior connections between receptor tails and the cell cytostructure where it can impact specific biochemical pathways. Our current research has provided significant insight into the mechanical strengths of leukocyte adhesion bonds and their kinetics under force, (i) first for interactions between the sialo mucin ligand PSGL-1 and selectins that initiate leukocyte attachments to vessel walls, (ii) second for interactions between super immunoglobulin (Ig) family ligands and integrins that signal and stabilize leukocyte adhesion enabling emigration into tissues. We have developed novel methods to immobilize ligands on the tip of ultrasensitive force probes and test the mechanical strengths of individual bonds to receptors either immobilized on microspheres or expressed on cells. Exploiting an exciting new approach and established cell lines with strategic alterations in receptor- cytoskeletal interactions, the principal objective of this application is to "move inside the cell", first establishing the extent to which cytostructural proteins regulate the mechanical strength of an adhesion complex, and then determining the mechanical role that these linkages play in the leukocyte signalling processes important for recruitment to sites of inflammation and injury. The studies are designed to test three hypotheses. Hypothesis: leukocyte selectin and integrin interactions have function-specific mechanical designs that govern bond formation and release under conditions of low stress interior to a cell- surface contact, thereby impacting bond proliferation and determining the fate of the initial adhesion event. Hypothesis: mechanical strengths of molecular adhesion complexes are governed by the weakest link in entire sequence of protein interactions from the outside adhesive bond to the inside bonds that connect receptor-tail domains to the cell cytostructure. Hypothesis: the linkages that anchor an integrin adhesion complex to the cell structure are key mechanical effectors of "outside-in" and "inside-out" signaling in leukocytes and represent an important feed-back process to regulate adhesion strength.

描述（由申请人提供）：我们的长期目标是在分子水平上对白细胞粘附进行详细的生物物理了解，将粘附强度与化学相互作用联系起来，并确定粘附应力如何通过细胞膜传递到受体之间的内部连接尾部和细胞细胞结构，在那里它可以影响特定的生化途径。我们目前的研究提供了重要的洞察力的机械强度的白细胞粘附键和他们的动力学下的力量，（i）首先唾液酸粘蛋白配体PSGL-1和选择素之间的相互作用，启动白细胞附着到血管壁，（ii）第二超级免疫球蛋白（IG）家族配体和整合素之间的相互作用，信号和稳定的白细胞粘附，使移民到组织。我们已经开发了新的方法来识别超灵敏力探针尖端上的配体，并测试固定在微球上或表达在细胞上的受体的各个键的机械强度。利用激动人心的新方法和在受体-细胞骨架相互作用中具有战略性改变的已建立的细胞系，本申请的主要目的是“在细胞内移动”，首先建立细胞结构蛋白调节粘附复合物的机械强度的程度，然后确定这些连接在白细胞信号传导过程中所起的机械作用，该过程对于募集到炎症和损伤部位是重要的。这些研究旨在验证三个假设。假设：白细胞选择素和整联蛋白的相互作用具有功能特异性的机械设计，其在细胞-表面接触内部的低应力条件下控制键的形成和释放，从而影响键的增殖并决定初始粘附事件的命运。假设：分子粘附复合物的机械强度由从外部粘附键到内部键的整个蛋白质相互作用序列中的最弱连接控制，所述内部键将受体尾结构域连接到细胞细胞结构。假设：将整联蛋白粘附复合物锚到细胞结构上的键是白细胞中“由外向内”和“由内向外”信号传导的关键机械效应物，并且代表调节粘附强度的重要反馈过程。