The Phagosensor Technique: Quantifying the force fields generated during phagocytosis using deformable microcapsules

Phagosensor 技术：使用可变形微胶囊量化吞噬过程中产生的力场

• 批准号: 0848797
• 负责人: Jennifer Curtis
• 金额: $ 24.29万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0848797&HistoricalAwards=false
• 关键词: Phagosensor; Technique; Quantifying; force; fields

In this project the PI will introduce a new quantitative technique that permits systematic studies of several fundamental areas in biological physics, including phagocytosis, the actin cytoskeleton and its coupling to membrane, and mechanotransduction. The approach, called the PhagoSensor Technique, uses mechanically characterized, deformable particles as the phagocytotic target. During phagocytosis, the soft particle experiences spatially and time-dependent deformations which reflect the transient forces exerted by the advancing cell extensions (pseudopodia) around the particle. High resolution imaging of the particle deformations combined with simultaneous imaging of the pseudopodia will provide unprecedented data regarding cell dynamics and mechanics during phagocytosis. The cell-generated force field that deforms the particle will be extracted via image processing and application of elastic shell theory. This work addresses three aspects of phagocytosis. First, the robustness and reproducibility of the mechanical signature of phagocytosis will be characterized. Second, the measured force dynamics will be correlated with the most prominent model of phagocytosis, which claims that there are three phases with at least two different and independent sources of contractile force. Last, the mechanosensitivity of macrophage cells by varying the elastic moduli of the PhagoSensors used during experimentation will be investigated. The fascinating and dramatic aspects of the biophysical studies, such as the visually stimulating process of one cell eating another or the holographic optical tweezers will be used to: (1) captivate 4-5th graders once a month in a hands-on after school Science Club; (2) to inspire undergraduates in universities like Florida International University (FIU) to pursue a career in quantitative biophysics; and (3) to extensively train undergraduates at Georgia Tech in a challenging interdisciplinary environment.

在该项目中，PI将引入一种新的定量技术，该技术允许对生物物理学的几个基本区域进行系统研究，包括吞噬作用，肌动蛋白细胞骨架及其与膜的偶联以及机械传递。该方法称为吞噬器技术，使用机械表征的可变形颗粒作为吞噬靶标。在吞噬作用期间，软粒子在空间上经历和时间依赖性变形，这些变形反映了粒子周围前进的细胞延伸（伪足）所施加的瞬态力。颗粒变形的高分辨率成像结合了伪虫的同时成像，将在吞噬细胞增多症期间提供有关细胞动力学和力学的前所未有的数据。变形粒子的细胞生成的力场将通过弹性壳理论的图像处理和应用提取。这项工作涉及吞噬作用的三个方面。首先，将表征吞噬作用的机械特征的鲁棒性和可重复性。其次，测得的力动力学将与最突出的吞噬作用模型相关，该模型声称有三个阶段至少具有两个不同且独立的收缩力来源。最后，将研究通过改变实验过程中使用的吞噬器的弹性模量来改变巨噬细胞的机械效应。生物物理研究的引人入胜且引人注目的方面，例如一个食用另一个细胞的视觉刺激过程或全息光学镊子将使用：（1）吸引每月4-5年级的4-5年级学生在校后的科学毕业后的一家动手。 （2）激发佛罗里达国际大学（FIU）等大学的大学生，从事定量生物物理学的职业； （3）在充满挑战的跨学科环境中，在佐治亚理工学院进行广泛培训本科生。