Neutrophil chemotaxis in autoinflammation

描述（由申请人提供）：中性粒细胞介导的炎症有助于许多疾病的发病机制，包括自身炎症综合征，心脏病，哮喘，风湿病和炎症性肠病。炎症反应的关键早期步骤是中性粒细胞向炎症部位的定向迁移。本提案的总体目标是了解体内调节中性粒细胞趋化的基本分子机制，并以斑马鱼为模型系统了解这些机制如何促进慢性炎症的发展。该建议的优势在于利用我们开发的新型转基因斑马鱼系来研究体内中性粒细胞趋化性和炎症。利用这些工具，我们观察到斑马鱼中性粒细胞在组织和脉管系统之间表现出双向迁移，而中性粒细胞的反向迁移有助于消除炎症反应。指导本研究的假设是，g蛋白偶联受体（GPCR）、磷酸肌肽信号和接头蛋白PSTPIP1介导的中性粒细胞趋化作用调节了体内组织和血管之间的中性粒细胞双向运输和炎症的发生。我们现在有了独特的定位，改进了在斑马鱼中性粒细胞中高效瞬时表达转基因或生物传感器探针的方法，以剖析调节中性粒细胞趋化性和体内双向迁移的分子机制。据此，我们提出以下具体目标：阐明磷酸肌苷信号如何调节斑马鱼的双向中性粒细胞运输和炎症。2. 2 .阐明GPCR信号通过CXCR4调控斑马鱼中性粒细胞双向转运和炎症的机制；以斑马鱼为模型系统，在体内研究自身炎症性疾病中性粒细胞趋化性。这项研究不仅将阐明调节中性粒细胞趋化的分子机制，而且还可能为慢性炎症的发病机制和控制疾病状态的新疗法的发展提供见解，其中炎症是发病机制的核心。公共卫生相关性：拟议的研究通过增加我们对以斑马鱼为模型系统调节白细胞运动、伤口愈合和炎症的分子机制的理解，有助于人类健康。了解体内调节中性粒细胞趋化的基本机制应该有助于确定自身炎症综合征和其他疾病状态的治疗靶点，其中炎症是发病机制的核心，包括心脏病、哮喘、关节炎和炎症性肠病。

DESCRIPTION (provided by applicant): Neutrophil-mediated inflammation contributes to the pathogenesis of many diseases including autoinflammatory syndromes, heart disease, asthma, rheumatic disease and inflammatory bowel disease. A key early step in the inflammatory response is the directional migration of neutrophils to sites of inflammation. The overall goal of this proposal is to understand the basic molecular mechanisms that regulate neutrophil chemotaxis in vivo, and to understand how these mechanisms contribute to the development of chronic inflammation using zebrafish as a model system. The strength of this proposal lies in the use of novel transgenic zebrafish lines that we have developed to study neutrophil chemotaxis and inflammation in vivo. Using these tools we have made the observation that zebrafish neutrophils exhibit bidirectional migration between tissues and the vasculature, and reverse neutrophil migration contributes to resolution of the inflammatory response. The hypothesis that guides this research is that neutrophil chemotaxis mediated by G-protein coupled receptors (GPCR), phosphoinositide signaling and the adaptor protein PSTPIP1 modulate bidirectional neutrophil trafficking between tissues and the vasculature and the development of inflammation in vivo. We are now uniquely positioned with improved methods for high efficiency transient expression of transgenes or biosensor probes in zebrafish neutrophils to dissect the molecular mechanisms that regulate neutrophil chemotaxis and bidirectional migration in vivo. Accordingly, we propose the following specific aims: 1. Elucidate how phosphoinositide signaling regulates bidirectional neutrophil trafficking and inflammation in zebrafish. 2. Elucidate how GPCR signaling through CXCR4 regulates bidirectional neutrophil trafficking and inflammation in zebrafish, and 3. Use zebrafish as a model system to examine neutrophil chemotaxis in autoinflammatory disease in vivo. The research proposed in this grant will not only elucidate the molecular mechanisms that regulate neutrophil chemotaxis, but will also likely provide insight into the pathogenesis of chronic inflammation and the development of new therapeutic for control of disease states in which inflammation is central to pathogenesis. PUBLIC HEALTH RELEVANCE: The proposed research contributes to human health by increasing our understanding of the molecular mechanisms that regulate leukocyte motility, wound healing and inflammation using zebrafish as a model system. Knowledge of the basic mechanisms that regulate neutrophil chemotaxis in vivo should aid in the identification of therapeutic targets for autoinflammatory syndromes and other disease states in which inflammation is central to pathogenesis, including heart disease, asthma, arthritis and inflammatory bowel disease.