Cellular and Molecular Biology of Inflammation and Repair

这是一项继续研究参与早期细胞的细胞和分子生物学的建议。 对损伤的炎症反应。需要检验的假设是，中性粒细胞(PMN)充当指导性细胞 在无菌炎症中调节巨噬细胞表型表达和引导巨噬细胞 替代或抗炎激活途径。这一假说预测，对 中性粒细胞的巨噬细胞炎症表型在组织损伤部位局部明显，在全身 在对诸如出血或长骨骨折等刺激的反应中。该项目的最新进展 为这一假设提供了支持。在这方面，中性粒细胞减少的小鼠伤口含有更多的肿瘤坏死因子-a和白介素6。 从中性粒细胞减少的伤口分离出的巨噬细胞含有和释放过量 肿瘤坏死因子-α和白介素6。体外收集的证据表明，中性粒细胞释放可溶性因子(S)小于3000Da 在不是腺苷、NO或COX产物的分子质量中，诱导抗- 炎症表型包括细胞因子/趋化因子mRNA和蛋白表达的变化，以及 抑制巨噬细胞中超氧化物的产生。还给出了与这些观察结果相关的补充信息 人多形核细胞培养上清液抑制脂多糖刺激的人肿瘤坏死因子-α释放 单核细胞来源的巨噬细胞。从系统上讲，向中性粒细胞减少的动物注射脂多糖会产生血清 肿瘤坏死因子-a的浓度是对照组的15倍，肝和脾的肿瘤坏死因子-a升高。 M RNA含量。为了检验这一假设，该提案被构造为四个不重叠的具体内容 目的：i)确定伤口PMN的表型。B.定义分子同一性 中性粒细胞释放的抑制巨噬细胞活化的因子(S)。二)建立打压机制 中性粒细胞因子产生巨噬细胞肿瘤坏死因子(S)。定义伤口巨噬细胞的表型。 B)调查PMN的影响。和PMN抑制产物对巨噬细胞表型和基因的影响 在急性无菌炎症中的表达，以及IV)决定PMN和PMN分泌产物在 对伤害的系统反应。完成拟议的研究将确定抗炎的特征 在分子、细胞、组织和系统水平上的PMN活性，并扩展当前对 中性粒细胞在确定炎症中巨噬细胞表型中的作用此前不为人知。

This is a proposal to continue the study of the cellular and molecular biology of cells participating in the early inflammatory response to injury. The hypothesis to be tested is that neutrophils (PMN) act as instructive cells in sterile inflammation by regulating macrophage phenotypic expression and directing macrophages along the alternative or anti-inflammatory activation pathway. The hypothesis predicts that the suppression of macrophage inflammatory phenotype by PMN is evident locally at sites of tissue injury, and systemically during the response to stimuli such as hemorrhage or long bone fracture. Recent progress on this project provides support for the hypothesis. In this regard, wounds in neutropenic mice contain more TNF-a and IL-6 than in normal controls, and macrophages isolated from neutropenic wounds contain and release excess TNF-a and IL-6. Evidence garnered in vitro demonstrated PMN release soluble factor(s) less than 3000 Da in molecular mass that are not adenosine, NO, or products of COX, that induce the expression of an anti- inflammatory phenotype consisting of alterations in cytokine/chemokine mRNA and protein expression, and the suppression of superoxide production in macrophages. Added relevance to these observations is given by the finding that human PMN culture supernatants suppress TNF-a release from LPS-stimulated human monocyte-derived macrophages. Systemically, injection of LPS into neutropenic animals results in serum TNF-a concentrations 15-fold higher than those in controls, and in increased hepatic and splenic TNF-a mRNA content. In order to test the hypothesis, the proposal is structured in four non-overlapping Specific Aims designed to: I) A. Characterize the wound PMN phenotype. B. Define the molecular identity of the factor(s) released by PMN that suppress macrophage activation. II) Establish the mechanism of suppression of macrophage TNF-a production by PMN factor(s). Ill)A. Define the phenotype of the wound macrophage. B) Investigate the impact of PMN. and PMN inhibitory products on macrophage phenotype and gene expression in acute sterile inflammation, and IV) Determine the role of PMN and PMN secretory products in the systemic response to injury. Completion of the proposed studies will characterize the anti-inflammatory activity of PMN at the molecular, cellular, tissue, and systemic levels, and expand current understanding of a previously unrecognized role of PMN in determining the phenotype of macrophages in inflammation.