Protective Effects of Anti-C5a in Sepsis

描述(由申请人提供)：根据我们迄今的研究，使用 盲肠结扎/穿刺术(CLP)所致脓毒症动物模型的建立 大鼠，先天免疫功能严重受损。这会导致什么结果 似乎是NADPH氧化酶组装中的C5a依赖缺陷和缺陷 中性粒细胞的吞噬功能。这些缺陷可以通过体外复制 中性粒细胞暴露于败血症中发现的C5a浓度。在第一个 目的：我们将评估中性粒细胞在体外暴露于C5a后的结果。 检测信号通路：佛波醇12-肉豆蔻酸酯13-醋酸酯(PMA)诱导 磷酸激酶C(PKC)的激活导致NADPH氧化酶的组装； 以及通过参与FcyRs激活细胞，导致吞噬反应。 在第二个目标中，我们将评估血液中相同的信号通路 CLP动物的中性粒细胞，并确定抗C5a治疗是否可以防止 信号有缺陷。在第三个目标中，我们将确定正常的治疗 大鼠和小鼠以及抗C5a的CLP大鼠和小鼠损害了天然免疫， 细菌清除率(假单胞菌属)。和克雷伯氏菌(Klebsiella sp.)从… 并评估其对生存的影响。在第四个目标中，我们将使用 CLP大鼠的基因芯片分析，以确定作为时间函数的改变 在易受损伤的器官中的全局基因表达 脓毒症(肝、肺、肾、胸腺)，并确定是否使用抗C5a治疗 阻止这种基因表达模式。有可能是微阵列 分析将预测败血症期间器官对损害的易感性。 总而言之，这些研究应该提供与 脓毒症时补体激活损害先天功能的机制 豁免权。

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.