Integrative Experimental and Theoretical Studies of the Mechanics of Phagocytosis

吞噬作用机制的综合实验和理论研究

• 批准号: 7572896
• 负责人: Volkmar Heinrich
• 金额: $ 33.36万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-15 至 2012-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7572896
• 关键词: Adhesions; Affect; Antibodies; Behavior; Biological Assay; Biological Models; Cells; Cellular Morphology; Characteristics; Coccidioides; Communicable Diseases; Complement; Computer Simulation; Custom; Data Analyses; Dependence; Development; Dictyostelium; Disease; Elements; Exhibits; Experimental Models; Failure; Figs - dietary; Germ Cells; Health; Human; Image; Immune; Immune response; Immunity; Immunofluorescence Immunologic; Individual; Infection; Infectious Agent; Knock-out; Leukocytes; Measurement; Measures; Mechanics; Mediating; Methods; Modeling; Molecular; Molecular Motors; Monitor; Morphology; Motor; Motor Activity; Movement; Mus; Myosin ATPase; Nature; Pathway interactions; Phagocytes; Phagocytosis; Pharmaceutical Preparations; Phenotype; Play; Positioning Attribute; Process; Property; Published Comment; Recovery; Research Personnel; Role; Solid; Stress; Structure; System; Testing; Theoretical Studies; Theoretical model; Time; United States; Validation; Variant; Video Microscopy; Work; base; cell motility; fungus; immune function; macrophage; mechanical behavior; monocyte; nanoscale; neutrophil; pathogen; physical model; programs; research study; response; success; theories; virtual

DESCRIPTION (provided by applicant): The phagocytic neutralization of pathogens plays a central role in host protection against, and recovery from infection. The proposed project aims to expose the major mechanical determinants of phagocytosis by firmly integrating single-cell experiments with advanced theoretical models of "virtual immune cells". This interdisciplinary effort ties closely into the long-term objective of establishing a solid quantitative understanding of autonomous cell motility and its role in the innate immune response. An integrative experimental/theoretical approach will first be used to establish a baseline of key models of phagocytosis (Aim 1) and of different phagocytic pathways (Aim 2). It will then be applied to genetically altered model systems in order to elucidate the mechanical roles of major molecular components for normal phagocytic function (Aim 3). The method's relevance as a valuable single-cell assay in studies of the innate immune function will be validated by examining the phagocytosis of infectious pathogens (Aim 4). The experimental configuration most suitable for close integration with theoretical models consists of an initially spherical cell that engulfs a spherical bead. Single-cell phagocytosis of spherical targets will be monitored using a custom-built videomicroscopy/micropipette-manipulation setup. Data analysis will provide the time courses of cellular morphology, cortical tension, and bead movement for each experiment. These quantitative measurements will serve as standards for the validation of finite-element computer models that are based on physically realistic and biologically plausible rules. The models' success in reproducing the observations will place strong constraints on the forces at play in phagocytosis. The changes in parameter values that are required to accommodate genetically altered or diseased states will noninvasively expose the impact of the affected nanoscale structures on molecular motor activity and cytoskeletal properties. The focus on a standardized single cell/single target configuration that is highly reproducible and simple enough to be quantitatively analyzed presents a unique viewpoint on the phagocytic phenotype. The integration of experiment and theory reveals in detail how the immune phagocytic response fails or succeeds depending on the nature of both phagocyte and pathogen. This is a determining element for the recovery from infectious challenges in human health.

描述（由申请方提供）：病原体的吞噬细胞中和作用在宿主抵抗感染和从感染中恢复中起着重要作用。该拟议项目旨在通过将单细胞实验与“虚拟免疫细胞”的先进理论模型紧密结合，揭示吞噬作用的主要机械决定因素。这一跨学科的努力与建立对自主细胞运动及其在先天免疫反应中的作用的可靠定量理解的长期目标密切相关。一个综合的实验/理论方法将首先用于建立一个基线的关键模型的吞噬作用（目标1）和不同的吞噬途径（目标2）。然后将其应用于遗传改变的模型系统，以阐明正常吞噬功能的主要分子组分的机械作用（目的3）。该方法作为先天免疫功能研究中有价值的单细胞测定的相关性将通过检查感染性病原体的吞噬作用来验证（目的4）。最适合与理论模型紧密结合的实验配置包括一个最初的球形细胞，吞噬一个球形珠。将使用定制的视频显微镜/微量移液器操作装置监测球形靶标的单细胞吞噬作用。数据分析将提供每个实验的细胞形态、皮质张力和珠运动的时间过程。这些定量测量将作为验证有限元计算机模型的标准，这些模型是基于物理现实和生物学上合理的规则。这些模型在再现观察结果方面的成功将对吞噬作用中起作用的力量产生强有力的限制。适应遗传改变或疾病状态所需的参数值的变化将非侵入性地暴露受影响的纳米级结构对分子运动活性和细胞骨架性质的影响。对标准化的单细胞/单靶配置的关注是高度可重复的，并且足够简单以进行定量分析，这提出了关于吞噬细胞表型的独特观点。实验和理论的结合详细揭示了免疫吞噬反应的失败或成功取决于吞噬细胞和病原体的性质。这是从人类健康的传染病挑战中恢复过来的一个决定性因素。