The role of beta 2 integrins in macrophage fusion

β2整合素在巨噬细胞融合中的作用

基本信息

批准号：
10082459
负责人：
Tatiana P Ugarova
金额：
$ 47.97万
依托单位：
ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-07-01 至 2023-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10082459
关键词：
Actins Adherens Junction Adhesives Affect Artificial Implants Attenuated Binding Sites Biocompatible Materials Biological Biology CD18 Antigens CD47 gene Cell Survival Cell membrane Chronic Complex Data Defect Deposition Dissection E-Cadherin Endogenous Retroviruses Enzymes Epithelial Event Extracellular Space Failure Fibrin Fibrinogen Fluorescence Foreign Bodies Foreign-Body Reaction Gene Targeting Genes Giant Cells Goals Grant Granulation Tissue Imaging Techniques Immunoelectron Microscopy Implant In Vitro Inflammation Integrins Knock-out Knowledge Ligands Macrophage-1 Antigen Medical Device Microfluidic Microchips Microfluidics Microscopy Modeling Molecular Mus Myeloid Cells Nanotechnology Phenotype Plasma Proteins Property Prosthesis Implantation Proteins Proteomics Recording of previous events Research Resolution Role Structure Surface System Testing Thick Time Translating Vascular Graft Video Microscopy Wild Type Mouse adhesion receptor base biomaterial development experimental study high resolution imaging implantation in vitro Model in vivo knock-down live cell imaging macrophage mechanical properties mouse model nectin novel polymerization protein E receptor response syncytin technological innovation

项目摘要

PROJECT SUMMARY Macrophage fusion resulting in the formation of multinucleated giant cells (MGCs) accompanies a variety of maladies associated with chronic inflammation, including the foreign body response (FBR) elicited by implanted biomaterials. Despite the long history of research on FBR, the molecular and cellular mechanisms of macrophage fusion, an event central to the long-term failure of implanted prosthetic vascular grafts and other medical devices, remain poorly understood. In our preliminary studies using in vivo implantation model, we found that the formation of MGCs and granulation tissue, which develops around the implant and is a precursor of the undesirable fibrotic cap, was almost completely abolished in fibrinogen-deficient mice. Surprisingly, the number of MGCs formed on biomaterials implanted into Mac-1-deficient mice was greater than in wild-type mice and the thickness of granulation tissue was larger. We hypothesize that macrophage fusion on biomaterials critically depends on the deposited fibrin(ogen) matrix and the absence of Mac-1, through the alteration of adhesive properties of macrophages, exacerbates the FBR. Specific Aim 1 is to test this hypothesis. Using a mouse model of biomaterial implantation and gene-targeted mice, we will perform systematic analyses of the early and late stages of FBR and determine the M1/M2 phenotype of MGCs derived from wild-type and Mac-1-deficient macrophages. Using nanotechnology approaches we will characterize the adhesive and mechanical properties of fibrin(ogen) matrices deposited on biomaterials in wild-type and Mac-1-deficient mice. Specific Aim 2 will characterize previously unrecognized actin- based zipper-like structures (ZLS) that form between MGCs on implanted biomaterials. We developed an in vitro model that reproduces the formation of ZLS and demonstrated that the intercellular space within ZLS is filled with junctional proteins E-cadherin and nectin-2. We hypothesize that MGCs form epithelial-like junctions that aid the MGC survival. Taking advantage of technological innovations including a microfluidic chamber that allows the precise dissection of ZLS followed by proteomics analyses, high-resolution microscopy, live cell imaging and mice with myeloid cell-specific KO of E- cadherin and other components of junctions, we will determine the composition of ZLS and their role in the FBR. Specific Aim 3 is to determine the role of authentic fusogenic proteins syncytins in macrophage fusion. Based on our finding that macrophage fusion is initiated by an actin-based protrusion, we will use knockdown experiments, EM and video microscopy to test the hypothesis that a fusion-competent protrusion at the leading edge of a donor macrophage contains syncytins. Overalls, these studies will define the novel biology of macrophage fusion and characterize new mechanisms that have the potential to modulate the FBR.

项目摘要巨噬细胞融合导致形成多核巨细胞（MGC）的巨噬细胞融合伴随与慢性炎症有关的疾病种类，包括外国体内反应（FBR）由植入的生物材料引起。尽管有关于FBR的研究的悠久历史，但分子和巨噬细胞融合的细胞机制，这是植入长期失败的核心假肢血管移植物和其他医疗设备仍然了解不足。在我们的初步中使用体内植入模型的研究，我们发现MGC和肉芽组织的形成，植入物周围发展，并且是不良纤维帽的前体，几乎是在缺陷型小鼠中完全废除。令人惊讶的是，在上形成的MGC数量植入MAC-1缺陷小鼠中的生物材料大于野生型小鼠，厚度肉芽组织的较大。我们假设巨噬细胞在生物材料上进行批判性融合取决于沉积的纤维蛋白（OGEN）基质和Mac-1的不存在，通过改变巨噬细胞的粘附特性，加剧了FBR。具体目的1是检验该假设。使用生物材料植入和基因靶向小鼠的小鼠模型，我们将进行系统性分析FBR的早期和晚期阶段，并确定MGC的M1/M2表型来自野生型和Mac-1缺陷巨噬细胞。使用纳米技术方法，我们将表征沉积在生物材料上的纤维蛋白（OGEN）矩阵的粘合剂和机械性能在野生型和MAC-1缺陷小鼠中。特定的目标2将表征先前未识别的肌动蛋白 - 基于植入生物材料的MGC之间形成的基于拉链样结构（ZLS）。我们开发了一种体外模型，该模型再现了ZLS的形成并证明了细胞间空间 ZLS内部充满了连接蛋白E-钙粘着蛋白和Nectin-2。我们假设MGC形式有助于MGC存活的上皮状连接。利用技术创新包括一个微流体室，该腔室允许精确解剖ZLS，然后是蛋白质组学分析，高分辨率显微镜，活细胞成像和小鼠E-的髓样细胞特异性KO 钙粘蛋白和交界处的其他组成部分，我们将确定Zls的组成及其在 FBR。具体目的3是确定正宗融合蛋白合成蛋白在巨噬细胞融合。根据我们的发现，巨噬细胞融合是由基于肌动蛋白的突出，我们将使用敲低实验，EM和视频显微镜来检验以下假设。供体巨噬细胞前缘的融合能力突出包含合蛋白。工作服，这些研究将定义巨噬细胞融合的新生物学，并表征新机制有可能调节FBR。