Adenosine and TLR regulation of costimulatory molecule expression in sepsis

描述(由申请人提供)：作为一名内科科学家，我的目标是进行实验室研究，这将推动该领域的发展，并改善我的患者的护理。我在传染病和重症监护医学的背景结合在一起，给了我独特的视角来研究脓毒症的临床问题。我将花费大约75%的时间从事科学研究，其余的时间作为重症监护在重症监护病房接受治疗，这将加强我对脓毒症的研究。K08奖将使我能够扩大我在脓毒症期间通过共刺激受体调节免疫反应的研究，并研究共刺激分子表达的调节作为脓毒症患者定制免疫治疗的一种潜在形式。在此期间，我将进一步发展我的研究事业：1)参加每周的免疫学研讨会和正式的课程作业；2)通过参加流式细胞术的高级培训课程来增强我的技术技能；3)出席IDSA、SCCM和休克学会的会议并展示我的工作。我的长期目标是获得RO1级别的资金，并从有指导的研究环境过渡到独立的研究人员。该项目将研究共刺激分子(CSM)在脓毒症免疫反应中的机制作用，以及Toll样蛋白(Toll-like，TLR)和腺苷受体介导的活性调节这些分子表达的能力。CSM在决定脓毒症宿主免疫反应和存活的动态过程中的作用尚未确定。TLRs通过识别微生物产物作为感染的早期检测器，并通过刺激炎性细胞因子的释放和上调抗原提呈细胞(APC)上的CSM来帮助启动免疫反应。最近的研究表明，腺苷受体具有调节APC和淋巴细胞上CSM表达的能力。我们的小组发现，缺乏腺苷2A或2B受体或接受A2BR药物阻断的脓毒症小鼠可以改善感染的清除和存活。利用特性良好的盲肠结扎穿孔(CLP)脓毒症小鼠模型，我们将1)纵向研究不同CSM在脓毒症小鼠中的表达，并确定它们与血浆中促炎和抗炎细胞因子水平、清除感染的能力以及T细胞增殖和效应功能的关系；2)确定单独激活或联合阻断特定的TLR和腺苷受体是否会改变CLP模型中CSM的表达，提高感染的清除和存活率；以及3)确定直接操作CSM表达是否可以改善脓毒症过程中的免疫功能，从而减少细菌负荷和提高生存率。总之，这些实验将描述CSM在脓毒症免疫反应中的作用，并确定CSM表达的药物调节是否是一种潜在的治疗干预措施。

DESCRIPTION (provided by applicant): My goals as a physician-scientist are to perform laboratory research that will advance the field, and improve the care of my patients. The combination of my background in Infectious Disease and Critical Care medicine gives me unique perspective from which to study the clinical problem of sepsis. I will spend approximately 75% of my time pursuing scientific research, and the remainder as a critical care attending in the intensive care units which will reinforce my focus on studies of sepsis. The K08 award will enable me to expand my studies of regulation of the immune response by costimulatory receptors during sepsis and investigate the modulation of costimulatory molecule expression as a potential form of tailored immunotherapy for septic patients. During this time I will further develop my research career though: 1) participation in weekly immunology seminars and formal coursework; 2) augmentation of my technical skills by attending advanced training courses in flow cytometry; and 3) attendance and presentation of my work at IDSA, SCCM and Shock Society conferences. My long term objective is to obtain RO1 level funding and transition from a mentored research environment to independent investigator. The proposed project will investigate the mechanistic role of costimulatory molecules (CSM) in the immune response during sepsis, and the ability of Toll-like (TLR) and adenosine receptor mediated activity to regulate expression of these molecules. The role of CSM to determine the dynamics of the immune response and survival of the septic host has not been defined. TLRs function as early detectors of infection through recognition of microbial products and help initiate an immune response through stimulating the release of inflammatory cytokines and upregulation CSM on antigen presenting cells (APCs). Recent work has shown that adenosine receptors have the capacity to modulate CSM expression on APCs and lymphocytes. Our group has found that septic mice lacking the adenosine 2A or 2B receptor or who receive pharmacologic blockade of A2BR have improved clearance of infection and survival. Using a well characterized mouse model of sepsis of cecal ligation and puncture (CLP) we will 1) Study the expression of different CSM longitudinally in septic mice and determine their association with pro and anti-inflammatory cytokine levels in plasma, ability to clear infection, and T cell proliferation and effector function, 2) Determine if activating or blocking specific TLRs and adenosine receptors singly, or in combination alters CSM expression and improves clearance of infection and survival in a CLP model of sepsis, and 3) Determine if direct manipulation of CSM expression improves immune function during sepsis to decrease bacterial load and increase survival. Together these experiments will characterize the role of CSM in the immune response to sepsis, and determine if pharmacologic modulation of CSM expression is a potential therapeutic intervention.