Hypoxia-induced Responses and Innate Immunity

巨噬细胞和嗜中性粒细胞作为先天免疫系统的组成部分对于感染的立即反应是必不可少的，并且这些细胞通常在微生物特别是细菌感染期间在缺氧微环境中发挥作用。我们的目标是通过研究缺氧诱导的转录因子HIF-1a在细菌攻击过程中的作用，确定骨髓细胞缺氧反应的机制。本提案的具体目的是：具体目的1：确定HIF-1a在调节骨髓细胞的微生物杀伤功能中的作用; 1a.分析在常氧、低氧和缺氧条件下HIF-1a在嗜中性粒细胞和巨噬细胞细菌杀伤中的作用; 1b.确定HIF-1a在 嗜中性粒细胞和巨噬细胞产生氧化爆发和活性氮物质; 1c. 确定HIF-1a在中性粒细胞蛋白酶活性和抗菌肽的产生和活化中的作用;具体目的2：确定HIF-1a在骨髓细胞的迁移、存活和免疫活化功能中的作用; 2a.分析在常氧、低氧和缺氧条件下HIF-1a在中性粒细胞趋化和内皮细胞转胞吞中的作用; 2b.确定HIF-1a在保护中性粒细胞和巨噬细胞免受细菌诱导的细胞毒性和细胞凋亡中的作用; 2c.确定HIF-1a在响应细菌刺激的中性粒细胞和巨噬细胞中促炎细胞因子基因激活模式中的作用;具体目标3：确定HIF-1a在先天免疫中的功能 针对体内细菌感染的防御; 3a.使用鼠皮下组织笼模型确定HIF-1a在局部中性粒细胞迁移和杀伤中的作用; 3b.用小鼠皮下感染模型确定HIF-1a在限制缺氧病灶感染全身扩散中的作用！3c.使用小鼠静脉内感染模型确定HIF-1a在细菌性败血症的发展和控制中的作用。

Macrophage and neutrophils are essential for an immediate response to infection as components of the innate immune system, and these cells often function in a hypoxic micro-environment during microbial, and especially bacterial, infection. Our goal is to determine the mechanisms of hypoxic response in myeloid cells during bacterial challenge, through studying the role of the hypoxia-induced transcription factor HIF-1a during that process. The specific aims of this proposal are: Specific aim 1: Determine the role of HIF-1a in regulating the microbial killing functions of myeloid cells; 1a. Analyze the role of HIF-1a in neutrophil and macrophage bacterial killing under normoxic, hypoxic and anoxic conditions; 1b. Determine the role of HIF-1a in neutrophil and macrophage production of the oxidative burst and reactive nitrogen species; 1c. Determine the role of HIF-1a in neutrophil protease activity and the production and activation of cathelicidin antimicrobial peptides; Specific aim 2: Determine the role of HIF-1a in the migratory, survival and immune-activating functions of myeloid cells; 2a. Analyze the role of HIF-1a in neutrophil chemotaxis and endothelial transcytosis under normoxic, hypoxic and anoxic conditions; 2b. Determine the role of HIF-1a in protection of neutrophils and macrophages against bacterial-induced cytotoxicity and apoptosis; 2c. Determine the role of HIF-1a in the pattern of proinflammatory cytokine gene activation in neutrophils and macrophages responding to a bacterial stimulus; Specific aim 3: Determine the function of HIF-1a in innate immune defense against bacterial infection in vivo; 3a. Determine the role of HIF-1a in localized neutrophil migration and killing using a murine subcutaneous tissue cage model; 3b. Determine the role of HIF-1a in restricting systemic spread of infection from a hypoxic focus using a murine subcutaneous infection mode!; 3c. Determine the role of HIF-1a in development and control of bacterial septicemia using a murine intravenous infection model.