Role of Macrophage Costimualtory Molecules in Polymicrobial Sepsis

脓毒症中的炎症主要由巨噬细胞活化的程度控制。共刺激 分子是一类能够在适应性免疫中激活巨噬细胞的受体。结扎 巨噬细胞通过活化T细胞表面的CD 154、CD 28/CTLA 4和LFA-1表达CD 40、CD 80/CD 86和ICAM。 细胞，增加NF-κ B DNA结合和C/EBPb的刺激/抑制亚型的比率。这导致 大量炎性细胞因子的产生增加。然而，共刺激分子在 在多微生物脓毒症期间的先天免疫应答没有被很好地描述。我们最近描述了CD 40- /-小鼠具有延迟的多微生物脓毒症死亡率，其中NF-kB活性和 刺激性/抑制性C/EBPb。我们现在提供的数据表明，中性粒细胞，先天免疫的主要组成部分， 脓毒症中的反应，可以通过共刺激分子的参与直接激活巨噬细胞 CD 40、CD 80/CD 86和ICAM。在体内，与WT相比，CD 80/CD 86-/-小鼠的存活率提高 CLP后小鼠。这与NF-kB、刺激性/抑制性C/EBPb比值以及 BAL和血浆中IL-6和IL-10水平。类似于在获得性免疫的摩尔中所报道的， 对多种共刺激分子的抑制提供了额外的益处。CD 40/CD 80/CD 86-/-小鼠 与CLP后的CD 80/86-/-小鼠相比，CD 80/CD 86-/-小鼠中的ICAM中和改善了存活率。在 在脓毒症患者中，我们发现PMN表达的CD 28、CTLA 4和CD 154上调，单核细胞 表达CD 40、CD 80/CD 86和ICAM。此外，可溶性异构体的 脓毒症患者CD 154、CD 28、ICAM和CTLA 4表达均高于健康对照组。 此外，sCD 28和sCD 154的水平仅在非存活者中上调，这表明潜在的 作为疾病活动的生物标志物。总之，这些结果表明，共刺激的重要作用， 败血症中的分子。在本提案中，我们计划将这些观察扩展到：1。表征动力学 CD 40-CD 154、CD 80/CD 86-CD 28/CTLA 4和ICAM-LFA-1系统在小鼠模型中的活性 多微生物败血症，2.通过一种新的方法检测多种共刺激分子的抑制在脓毒症中的作用。 CD 40/CD 80/CD 86-/-小鼠，和3.充分评估共刺激分子表达的意义 以及在患有脓毒症和脓毒性休克的人中的体内和离体活性。

Inflammation in sepsis is controlled primarily by the degree of macrophage activation. Costimulatory molecules are a class of receptors capable of macrophage activation in adaptive immunity. Ligation of macrophage expressed CD40, CD80/CD86 and ICAM by CD154, CD28/CTLA4 and LFA-1 on activated T- cells, increases NF-kB DNA binding and the ratio of stimulatory/inhibitory isoforms of C/EBPb. This results in increased production of numerous inflammatory cytokines. However, the role for costimulatory molecules in the innate immune response during polymicrobial sepsis is not well described. We recently described CD40- /- mice have delayed mortality with polymicrobial sepsis with attenuations in NF-kB activity and the ratio of stimulatory/inhibitory C/EBPb. We now present data that neutrophils, a main component of innate immune response in sepsis, can directly activate macrophages via engagement of the costimulatory molecules CD40, CD80/CD86 and ICAM in vitro. In vivo, CD80/CD86-/- mice have improved survival compared to WT mice after CLP. This was associated with a reduction in NF-kB, the ratio of stimulatory/inhibitory C/EBPb and levels of IL-6 and IL-10 in BAL and plasma. Similar to what has been reported in moels of adaptive immunity, inhibtion for multiple costimulatory molecules provided additional benefit. Both CD40/CD80/CD86-/- mice and ICAM neutralization in CD80/CD86-/- mice improved survival compared to CD80/86-/- mice after CLP. In humans with sepsis, we found upregulation of PMNexpressed CD28, CTLA4 and CD154, and monocyte expressed CD40, CD80/CD86 and ICAM compared to healthy controls. In addition, the soluble isoforms of CD154, CD28, ICAM and CTLA4 were upregulated in septic patients comparedto healthy controls. Furthermore, levels of sCD28 and sCD154 were only upregulated in non-survivors, suggesting a potential role as a biomarker of disease activity. Together, these results suggest an important role for costimulatory molecules in sepsis. In this proposal we plan to extend these observations to: 1. Characterize the kinetics and activity of the CD40-CD154, CD80/CD86-CD28/CTLA4 and ICAM-LFA-1 systems in a murine model of polymicrobial sepsis, 2. Test the effect of inhibition of multiple costimulatory molecules in sepsis via a novel CD40/CD80/CD86-/- mouse, and 3. To fully assess the significance of costimulatory molecule expression and activity both in vivo and ex vivo in humans with sepsis and septic shock.