The mechanochemical control of T-cell directional migration under flow

流动下T细胞定向迁移的机械化学控制

• 批准号: 9752590
• 负责人: Daniel A Hammer
• 金额: $ 43.31万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9752590
• 关键词: Actins; Address; Adhesions; Adhesives; Automobile Driving; Cell Adhesion Molecules; Cell Line; Cell Therapy; Cells; Communicable Diseases; Communication; Coupling; Cytoskeleton; Dependence; Engineering; Event; Exhibits; Exposure to; Generations; Goals; Homing; Human; Immune; Immune system; Inflammation; Inflammatory; Integrin alpha4beta1; Integrins; Intercellular adhesion molecule 1; Lead; Ligands; Ligation; Lymph; Lymphoid; Malignant Neoplasms; Measures; Mechanics; Memory; Methods; Microfabrication; Molecular; Motion; Organ; Pharmacological Treatment; Process; Proteins; Research Personnel; Salmon; Signal Pathway; Signal Transduction; Site; Surface; Swimming; System; T cell response; T cell therapy; T-Lymphocyte; Testing; Time; Vascular Cell Adhesion Molecule-1; Very Late Antigen Receptors; Work; adaptive immune response; biophysical tools; cell motility; chimeric antigen receptor; detector; differential expression; directional cell; fascinate; imaging modality; improved; lymph flow; migration; mucosal addressin cell adhesion molecule-1; novel; novel therapeutic intervention; polydimethylsiloxane; polymerization; receptor; response; therapeutic development; tool; trafficking

The mechanochemical control of T-cell directional migration under flow Daniel A. Hammer (PI) and Janis K. Burkhardt (co-Investigator) Project Summary T-lymphocytes are key players in the adaptive immune response, and motility is critical to their function. T- cells are equipped with multiple different adhesion molecules that interact with ligands that are expressed differentially throughout the immune system. Furthermore, T-cells often must act under an imposed flow field as they traffic through the vasculature and lymphic system. Our goal is to understand how T-cells respond to the different adhesion ligands and shear rates they encounter to effectively migrate to sites of inflammation and immune communication. Understanding this process at the molecular level is important for development of therapeutic strategies to treat inflammatory and infectious diseases, and cancer Recently, we have discovered that directional T-cell migration varies as a function of the type of ligand they encounter and the shear rate to which they are exposed. When placed on a surface bearing vascular cell adhesion molecule-1 (VCAM-1), which engages the 1-integrin receptor VLA-4, T-cells crawl downstream under flow (in the direction of flow). However, when placed on a surface bearing intercellular adhesion molecule-1 (ICAM-1), which engages the 2-receptor LFA-1, T-cells crawl against the direction of flow, like a salmon swims upstream. The magnitude of upstream migration depends on shear rate, with T-cells more committed to upstream migration as the shear rate increases. On surfaces in which adhesion molecules are mixed, any amount of ICAM-1 supports upstream migration. When the flow is removed, T-cells exhibit migrational memory, but only if they have been exposed to both ICAM-1 and VCAM-1. This observation points to a novel mechanism of crosstalk between two distinct integrin receptors. We propose to investigate the mechanisms that drive the upstream migration of T-cells under flow on ICAM-1, and the origins of migrational memory. We hypothesize that upstream migration is caused by 2 integrin forming a catch bond, which holds the cell in place while signals generated by integrin ligation strengthen adhesive interactions and spur the polymerization of actin at the leading edge, driving forward migration. To test this, we will use molecular engineering, flow chambers, micropatterned surfaces, and microfabricated post array detectors (mPADs) to measure forces exerted by the migrating cell. We have preliminary evidence that other motile amoeboid cells such as the immortalized KG1a cell line display the same phenomenon, facilitating our use of molecular engineering tools and imaging methods to identify the relevant molecules. By dissecting the mechanisms that underlie this fascinating phenomenon, we expect to elucidate key features of integrin-dependent T cell trafficking. Our aims in this work are to: 1. Measure the dynamics of T-cell and KG1a directional motion and migrational memory; 2. Identify the signals and clutch molecules responsible for the differential migration under flow in response to 1 and 2 integrin ligands; and 3. Measure the mechanisms of force generation when T-cells spread and crawl directionally on integrin ligands.

流动下T细胞定向迁移的机械化学控制 Daniel A. Hammer (PI) 和 Janis K. Burkhardt（联合研究员） 项目概要 T 淋巴细胞是适应性免疫反应的关键参与者，其运动性对其功能至关重要。 T- 细胞配备有多种不同的粘附分子，可与表达的配体相互作用 整个免疫系统存在差异。此外，T 细胞通常必须在强加的流场下发挥作用 当它们穿过脉管系统和淋巴系统时。我们的目标是了解 T 细胞如何响应 它们遇到的不同粘附配体和剪切速率有效地迁移到炎症部位 免疫通讯。在分子水平上理解这一过程对于开发 治疗炎症和传染病以及癌症的治疗策略 最近，我们发现定向 T 细胞迁移随其配体类型的变化而变化。 接触和它们所承受的剪切速率。当放置在带有血管细胞的表面上时 粘附分子-1 (VCAM-1)，与 1-整合素受体 VLA-4 结合，T 细胞向下游爬行 处于流动状态（沿流动方向）。然而，当放置在具有细胞间粘附的表面上时 分子 1 (ICAM-1) 与 2 受体 LFA-1 结合，T 细胞逆着流动方向爬行，就像 鲑鱼逆流而上。上游迁移的幅度取决于剪切速率，T 细胞更多 随着剪切速率的增加，致力于向上游迁移。在有粘附分子的表面 混合，任意数量的 ICAM-1 支持上游迁移。当流动被移除时，T细胞表现出 迁移记忆，但前提是它们同时暴露于 ICAM-1 和 VCAM-1。这个观察点 两个不同的整合素受体之间串扰的新机制。 我们建议研究驱动 T 细胞在流动下向上游迁移的机制。 ICAM-1，和迁移记忆的起源。我们假设上游迁移是由 2 引起的 整合素形成捕获键，将细胞固定在适当的位置，同时整合素连接产生信号 加强粘附相互作用并刺激前沿肌动蛋白的聚合，推动前进 迁移。为了测试这一点，我们将使用分子工程、流动室、微图案表面和 微型柱阵列探测器（mPAD）用于测量迁移细胞施加的力。我们有 初步证据表明其他运动变形虫细胞（例如永生化 KG1a 细胞系）显示出 同样的现象，有助于我们使用分子工程工具和成像方法来识别 相关分子。通过剖析这一令人着迷的现象背后的机制，我们期望 阐明整合素依赖性 T 细胞运输的关键特征。我们这项工作的目标是： 1. 衡量 T 细胞和 KG1a 定向运动和迁移记忆的动力学； 2. 识别信号和离合器 负责响应 1 和 2 整合素配体的流动下差异迁移的分子；和 3. 测量 T 细胞在整合素配体上定向扩散和爬行时产生力的机制。