Mechano-dynamics of the Transition to Firm Adhesion and MoIotility in Neutrophils

中性粒细胞向牢固粘附和运动性转变的机械动力学

• 批准号: 8006825
• 负责人: Daniel A Hammer
• 金额: $ 23.69万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8006825
• 关键词: Adhesions; Adhesives; Affect; Antibodies; Atomic Force Microscopy; Behavior; Biological Assay; Blood; Boston; Cell Adhesion Molecules; Cell Polarity; Cell surface; Cells; Cellular Stress; Chemicals; Chemotactic Factors; Collaborations; Complex; Computing Methodologies; Cues; Data; Defect; Disease; Endothelial Cells; Endothelium; Engineering; Environment; Extravasation; GTP-Binding Proteins; Generations; Goals; HL-60 Cells; Health Sciences; Homing; Image; Inflammation; Inflammatory; Inflammatory Response; Integrin Binding; Integrins; Intervention; Kinetics; Knockout Mice; Laboratories; Lead; Learning; Leukocytes; Location; Macrophage-1 Antigen; Malignant Neoplasms; Measurable; Measures; Mechanics; Mediating; Methods; Microfluidics; Modeling; Molecular; Molecular Probes; Motion; Neutrophil Activation; Pharmacologic Substance; Property; Reaction; Research; Role; Shapes; Signal Transduction; Simulate; Small Interfering RNA; Source; Speed; Stress; System; Techniques; Technology; Testing; Time; Tissues; Traction; Transfection; Universities; Work; adhesion process; adhesion receptor; base; cell motility; chemokine; density; inhibitor/antagonist; insight; migration; neutrophil; research study; response; role model; simulation; therapy design; tool

Neutrophils are the first line of defense in the cellular inflammatory response, and studying their behavior can lead to strategies for treating inflammatory disorders. Using quantitative tools and assays, we propose to investigate the fundamental mechano-chemical processes of adhesion and motility that control neutrophil extravasation from blood into tissue. In aim 1, we will simulate integrin-mediated firm adhesion of a neutrophil by merging Adhesive Dynamics - a mechanically accurate method for modeling adhesion - with a stochastic simulation of inside-out signal transduction. These models will predict how the rate and extent of neutrophil firm adhesion are controlled by a neutrophil's internal molecular machinery. Furthermore, we will use stochastic signaling methods to analyze experiments performed in Project 3 in which a neutrophil held in a pipette is stimulated by impingement with a moleculariy-coated bead. In aim 2, we will test predictions from the modeling in aim 1 by performing flow chamber adhesion experiments in which external and internal variables are systematically varied, to confirm that our quantitative understanding of the molecular control of adhesion is correct. Working closely with Projects 2 and 5, we will use pharmacological intervention, antibodies, and sIRNA technology to adjust neutrophil components and examine their effect on the transition to firm adhesion. In aim 3, we will work with Core C and use traction force microscopy to examine the motility of neutrophils in well-defined gradients of chemoattractant. We have built a chamber that combines microfluidics, to impose well-defined chemoattractant gradients across cells, with traction force microscopy. The goal is to understand how speed and direction in neutrophil motility is related to force generation, and to understand how the molecular components in neutrophils control contractility. Previous work has shown that neutrophil directional motion is accompanied by strong loci of contractile traction stress in the uropod. Using pharmacological inhibition, antibodies and sIRNA technology, we will measure how key molecular players affect neutrophil polarity, the generation of traction stresses, and cell motion. In summary, our work will provide fundamental insights as to how molecular components control neutrophil function in inflammation.

中性粒细胞是细胞炎症反应的第一道防线，研究它们的行为可以 导致治疗炎症性疾病的策略。使用定量工具和分析，我们建议 研究控制中性粒细胞的粘附和运动的基本机械化学过程 从血液外渗到组织中。在目标 1 中，我们将模拟整合素介导的牢固粘附 通过将 Adhesive Dynamics（一种模拟粘附的机械精确方法）与 由内而外信号转导的随机模拟。这些模型将预测 中性粒细胞的牢固粘附是由中性粒细胞的内部分子机制控制的。此外，我们将 使用随机信号方法来分析项目 3 中进行的实验，其中中性粒细胞保持 在移液管中，通过分子涂覆的珠子的撞击来刺激。在目标 2 中，我们将测试预测 根据目标 1 中的建模，通过执行流动室粘附实验，其中外部和内部 变量是系统变化的，以确认我们对分子控制的定量理解 附着力正确。与项目 2 和 5 密切合作，我们将使用药物干预， 抗体和 sIRNA 技术来调整中性粒细胞成分并检查它们对转变的影响 以牢固粘合。在目标 3 中，我们将与 Core C 合作并使用牵引力显微镜来检查 中性粒细胞在明确的化学引诱剂梯度中的运动。我们建造了一个结合了 微流体，通过牵引力显微镜在细胞之间施加明确的化学引诱剂梯度。 目标是了解中性粒细胞运动的速度和方向如何与力的产生相关，并 了解中性粒细胞中的分子成分如何控制收缩性。之前的工作表明 中性粒细胞的定向运动伴随着尾足中强烈的收缩牵引应力位点。使用 药理抑制、抗体和 sIRNA 技术，我们将衡量关键分子参与者 影响中性粒细胞极性、牵引应力的产生和细胞运动。总而言之，我们的工作将 提供关于分子成分如何控制炎症中中性粒细胞功能的基本见解。