Hydrodynamic Interactions and Cell Deformation in Neutrophil Adhesion

项目5的中心目标是了解流体剪应力、细胞形态和 L-选择素在中性粒细胞内皮细胞系留滚动动力学中的表达。我们将使用 结合最新的计算模拟的受体介导的细胞黏附在流动，在 分离的人中性粒细胞和中性粒细胞样细胞系在充气流体剪切中的体外实验 环境，以及与其他项目的协作投资。多粒子粘合动力学 由PI开发的模拟，使以前未解决的问题，如 非球形对白细胞滚动物理的影响及计算和实验 L-选择素脱落与机械传感的研究。众多的物理决定因素结合在一起 控制中性粒细胞炎症募集，包括受体表达、激活状态、细胞形态、局部 流动环境和细胞-细胞碰撞是高度复杂和非线性的，所以我们采取了 系统集成的工程学方法来解释这些行为。建议的工作是有组织的 围绕三个具体目标。目的1：Selecfin介导的激活的白细胞的拴系和滚动 目的利用多粒子黏附动力学模拟被激活的细胞形态，并对其进行详细的分析。 活体观察活化细胞滚动，研究非球形细胞黏附动力学。目标2： 轧制过程中L选择的机械传递和剥离机理。这一目标将探索 中性粒细胞和中性粒细胞在流室实验中机械脱落的分子机制 一种改变的中性粒细胞样细胞系。目的3：化学诱导剂诱导的抗剪切性 GPCRs。在这个目标中，我们将研究剪应力依赖的gpr介导的量子动力学。 中性粒细胞对fMLP和血小板激活因子(PAF)的反应。总之，拟议的研究将 确定第一个FIME非球形白细胞的物理形状，以及机械响应 中性粒细胞受体在单分子水平上，影响细胞系留和滚动的动力学 生理血流状态下的血管内皮细胞选择素。

The central goal of Project 5 is to understand the interplay between fluid shear stress, cell morphology, and L-selectin expression on the dynamics of neutrophil tethering and rolling on the endothelium. We will use a combination of state-of-the-art computational simulations of receptor-mediated cell adhesion under flow, in vitro experiments with isolated human neutrophils and neutrophil-like cell lines in well-deflned fluid shear environments, and collaborative invesfigafion with other projects. The mulfiparticle adhesive dynamics simulafion developed by the PI, enables the invesfigafion of previously unaddressed problems such as the influence of non-spherical shape on the physics of leukocyte rolling, and computational and experimental study of L-selecfin shedding and mechanosensing. The multitude of physical determinants combining to control neutrophil inflammatory recruitment, including receptor expression, activation state, cell shape, local flow environment, and cell-cell collisions are highly complex and nonlinear and so we have taken a systematic integrated engineering approach to elucidate these behaviors. The proposed work is organized around three specific aims. Aim 1: Selecfin-Mediated Tethering and Rolling of Activated Leukocytes: In this aim we will use mulfiparticle adhesive dynamics simulafions of acfivated cell shapes, and detailed analysis of in vivo observations of activated cell rolling, to study the dynamics of non-spherical cell adhesion. Aim 2: Mechanisms of L-Selecfin Mechanotransducfion and Shedding During Rolling. This aim will explore the molecular mechanisms of mechanical shedding in flow chamber experiments with primary neutrophils and an altered neutrophil-like cell line. Aim 3: Shear-Induced Resistance to Activation via Chemoattractant GPCRs. In this aim, we will study the quantitafive dynamics of the shear stress-dependent GPCR-mediated response of neutrophils to fMLP and platelet activating factor (PAF). Together, the proposed research will determine for the first fime how the physics of nonspherical leukocyte shape, and the mechanical response of neutrophil receptors at the single molecule level, influence the dynamics of cell tethering and rolling to selecfin-presenfing endothelium under physiological flow.