Protective Effects of Anti-C5a in Sepsis

描述（由申请人提供）：根据我们迄今为止的研究， 盲肠结扎穿孔（CLP）致脓毒症动物模型 大鼠，先天免疫力严重受损。这会导致什么 似乎是NADPH氧化酶组装中的C5 a依赖性缺陷， 中性粒细胞的吞噬功能。这些缺陷可以通过体外 中性粒细胞暴露于脓毒症中发现的C5 a浓度。上 目的是，我们将评估中性粒细胞体外暴露于C5 a如何导致 检测信号通路：佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）诱导 磷酸激酶C（PKC）的活化，其导致NADPH氧化酶的组装; 以及通过Fc γ R的接合导致吞噬反应的细胞活化。 在第二个目标中，我们将评估血液中相同的信号通路 从CLP动物的中性粒细胞，并确定是否与抗C5 a治疗预防 有缺陷的信号在第三个目标中，我们将确定是否治疗正常 具有抗C5 a的大鼠和小鼠以及CLP大鼠和小鼠损害先天免疫， 通过细菌清除率（假单胞菌属和克雷伯氏菌属）评估从 并评估对生存的影响。在第四个目标中，我们将使用 CLP大鼠的微阵列分析，以确定作为时间函数的变化， 在易受损伤的器官中， 脓毒症（肝、肺、肾、胸腺），并确定是否使用抗C5 a治疗 阻止了这种基因表达模式。有可能微阵列 分析将预测脓毒症期间器官对损伤的敏感性。 总的来说，这些研究应该提供与 脓毒症期间补体激活损害先天性 免疫力

DESCRIPTION (provided by applicant): On the basis of our studies to date using the experimental model of sepsis induced by cecal ligation/puncture (CLP) in rats, serious impairment of innate immunity develops. This results in what appears to be a C5a-dependent defect in assembly of NADPH oxidase and defective phagocytic function of neutrophils. These defects can be reproduced by in vitro exposure of neutrophils to concentrations of C5a found in sepsis. In the first aim, we will evaluate how in vitro exposure of neutrophils to C5a results in detective signaling pathways: phorbol 12-myristate 13-acetate (PMA)-induced activation of phosphokinase C (PKC) which results in assembly of NADPH oxidase; and cell activation by engagement of FcyRs resulting in phagocytic responses. In the second aim, we will evaluate the same signaling pathways in blood neutrophils from CLP animals and determine if treatment with anti-C5a prevents defective signaling. In the third aim, we will determine if treatment of normal rats and mice and CLP rats and mice with anti-C5a compromises innate immunity, as assessed by bacterial clearance (Pseudomonas sp. and Klebsiella sp.) from lungs and evaluate the effects on survival. In the fourth aim, we will employ microarray analysis in CLP rats to define, as a function of time, alterations in global gene expression in organs that are predisposed to injury during sepsis (liver, lungs, kidneys, thymus) and determine if treatment with anti-C5a prevents this pattern of gene expression. It is possible that microarrary analysis will be predictive of organ susceptibility to damage during sepsis. Collectively, these studies should provide important evidence related to the mechanisms by which complement activation during sepsis impairs innate immunity.