Resistance of Beta 2 Microglobulin Null Mice to Sepsis

我们已经令人信服地表明，自然杀伤(NK)细胞促进了败血症的发病。 盲肠结扎穿刺术(CLP)。然而，促进NK细胞介导的机制 脓毒症时的促炎活性还知之甚少。我们最近的研究表明 CLP诱导过程中CXCR3+NK细胞从脾到腹膜的数量 败血症。CXCR3配体CXCL9和CXCL10在脓毒症和 CXCR3基因缺陷小鼠对CLP诱导的生理功能障碍具有抵抗力。基于这些 观察到，我们假设CXCR3信号对招募和激活至关重要 并认为CXCR3的作用在脓毒症的发病机制中起重要作用。这个 遵循特定的目标将检验这些假设。具体目标1：确定 CXCR3对NK细胞迁移和激活的影响及其在CLP发病机制中的作用 诱发性败血症。NK细胞上CXCR3和活化标志物的表达将在 感染的主要部位和远处组织中。进一步的研究将评估NK细胞的招募和 CXCR3缺陷小鼠的激活以及中和抗体阻断CXCR3后。我们会 也确定了CXCR3在亚致死性脓毒症发病机制中的重要性，脓毒症诱导的多个 器官功能障碍和感染性休克。具体目标2.确定CXCR3的重要性 NK细胞募集和激活的配体(CXCL9和CXCL10)及其对人类免疫功能的影响 CLP致脓毒症的发病机制。CXCR3配体在初级位点的细胞来源 将对感染和远程组织进行检查。将研究NK细胞的迁移和激活 CXCR3配体缺陷小鼠或使用中和抗体阻断CXCR3配体后。 CXCR3配体将检测生理功能、器官损伤和全身炎症- 利用亚致死性脓毒症、脓毒症诱导的多器官功能障碍和脓毒症模型的缺陷小鼠 令人震惊。我们还将确定CXCR3配体直接诱导脓毒症综合征的能力。 对照小鼠或患有亚致死性脓毒症的小鼠。具体目标3.评估调节 CXCR3轴在CLP诱导的脓毒症中的作用这些研究将检验NK细胞对 脓毒症时CXCR3配体的产生及其调节NK细胞CXCR3表达的因素 尽管内毒素诱导的巨噬细胞产生CXCL10被认为是由 ，并需要产生干扰素，我们认为NK细胞将促进MyD88- 通过产生干扰素来依赖CXCL10的产生。在本申请中提出了研究建议 来回应这一断言。进一步的研究将评估旁分泌和自分泌的重要性。 NK细胞CXCR3激活机制及调节CXCR3表达的因素

We have convincingly shown that natural killer (NK) cells facilitate the pathogenesis of sepsis caused by cecal ligation and puncture (CLP). However, the mechanisms that contribute to NK cell-mediated pro-inflammatory activity during sepsis are poorly understood. Our recent studies indicate large numbers of CXCR3+ NK cells leave the spleen and enter the peritoneal cavity during CLP-induced sepsis. The CXCR3 ligands CXCL9 and CXCL10 are present at high concentrations during sepsis and CXCR3-deficient mice are resistant to CLP-induced physiologic dysfunction. Based on these observations, we hypothesize that CXCR3 signaling is critical for the recruitment and activation of NK cells and that the actions of CXCR3 are important in the pathogenesis of sepsis. The following specific aims will test these hypotheses. Specific Aim 1: To determine the importance of CXCR3 for NK cell migration and activation as well as its impact on the pathogenesis of CLP- induced sepsis. The expression of CXCR3 and markers of activation will be evaluated on NK cells at the primary site of infection and in remote tissues. Further studies will assess NK cell recruitment and activation in CXCR3-deficient mice and after blockade of CXCR3 with neutralizing antibodies. We will also determine the importance of CXCR3 in the pathogenesis of sublethal sepsis, sepsis-induced multi- organ dysfunction and septic shock. Specific Aim 2. To determine the importance of CXCR3 ligands (CXCL9 and CXCL10) for NK cell recruitment and activation as well as their impact on the pathogenesis of CLP-induced sepsis. The cellular sources of CXCR3 ligands at the primary site of infection and remote tissues will be examined. NK cell migration and activation will be studied in CXCR3 ligand-deficient mice or after blockade of CXCR3 ligands using neutralizing antibodies. Physiological function, organ injury and systemic inflammation will be examined in CXCR3 ligand- deficient mice using models of sublethal sepsis, sepsis-induced multi-organ dysfunction and septic shock. We will also determine the ability of CXCR3 ligands to directly induce the sepsis syndrome in control mice or mice with sublethal sepsis. Specific aim 3. Evaluation of factors that regulate the CXCR3 axis during CLP-induced sepsis. These studies will examine the contributions of NK cells to CXCR3 ligand production and the factors that regulate NK cell CXCR3 expression during sepsis. Although LPS-induced CXCL10 production by isolated macrophages is considered to be regulated by Trif-dependent signaling and require production of IFN¿, we propose that NK cells will facilitate MyD88- dependent CXCL10 production through the production of IFN¿. Studies are proposed in this application to address that assertion. Further studies will evaluate the importance of paracrine and autocrine mechanisms for NK cell CXCR3 activation and the factors that regulate CXCR3 expression by NK cells.