Alcohol Intoxication and Postburn Intestinal Immunity

酒精中毒和烧伤后肠道免疫

• 批准号: 7686438
• 负责人: Mashkoor A Choudhry
• 金额: $ 19.48万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-10 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7686438
• 关键词: Acute; Admission activity; Adult; Alcoholic Intoxication; Alcohols; Animals; Antibiotics; Antibodies; Appearance; Bacteria; Bacterial Translocation; Blood; Blood Circulation; Burn injury; Cell physiology; Cessation of life; Consumption; Containment; Decontamination; Dendritic Cells; Development; Dextrans; Edema; Enzymes; Event; Exhibits; Experimental Models; Fluorescein; Fluoresceins; Functional disorder; Goals; Hospitals; Immune; Immunity; Infection; Injury; Interleukin-10; Interleukin-12; Interleukin-18; Interleukin-2; Interleukin-4; Intestines; Isothiocyanates; Laboratories; Lead; Link; Lymphoid; MAPK8 gene; Measurable; Measurement; Measures; Mediating; Mesentery; Mitogen-Activated Protein Kinases; Modeling; Molecular Biology Techniques; Morbidity - disease rate; Organ; Pathogenesis; Patients; Permeability; Play; Population; Production; Rattus; Recombinants; Research Personnel; Role; STAT protein; Signal Transduction; Small Intestines; Source; Structure of aggregated lymphoid follicle of small intestine; T-Cell Proliferation; T-Lymphocyte; Therapeutic; Time; Tissues; Transcriptional Activation; Transducers; Up-Regulation; concept; cytokine; design; dextran; experience; fluorescein isothiocyanate dextran; injured; insight; interleukin-1beta-converting enzyme inhibitor; lymph nodes; macrophage; mortality; novel; prevent; programs; restoration

DESCRIPTION (provided by applicant): Alcohol (EtOH) intoxication remains a major factor in post-burn pathogenesis. Recent studies from our laboratory have shown that acute EtOH intoxication before burn injury results in: 1) decreased intestinal lymphoid [Peyer's patches (PP) and mesenteric lymph nodes (MLN)] T cell proliferation, IL-2 and IFN-y production; 2) decreased MLN IL-12 production; 3) increased PP and MLN IL-18 production; 4) increased intestinal permeability; and 5) increased bacterial accumulation in MLN. Treatment of rats with Ac-YVAD- CHO, (5 mg/kg), an inhibitor of Caspase-1 (an enzyme that converts pro-IL-18 to mature IL-18), prevents the EtOH and burn-mediated decrease in MLN IFN-y production and the development of intestinal edema. These preliminary findings collectively suggest that IL-18 up-regulation together with a decrease in IL-12 production plays a role in altered intestinal immunity and barrier function following EtOH intoxication and burn injury. Previous studies have suggested that impaired intestinal barrier function and subsequent release of bacteria and their products play significant roles in post-burn pathogenesis. Therefore the overall goal of the proposed studies is to delineate mechanism responsible for impaired intestinal immunity and barrier function following EtOH intoxication and burn injury. We hypothesize that IL-18 up-regulation in the absence of IL-12 production in intestinal lymphoid organs following EtOH intoxication and burn injury results in decreased intestinal immunity and impaired barrier function. Using a rat model of acute EtOH intoxication and burn injury, studies in Specific Aim 1 will characterize the source (macrophage/dendritic cell) of altered IL-18 and IL-12 and determine whether IL-12 restitution alone by administering recombinant IL-12 or in combination with IL-18 inhibition by neutralizing anti-IL18 antibody prevents the: 1) suppression of intestinal immunity, and 2) impaired intestinal barrier function following EtOH intoxication and burn injury. Intestinal immunity will be determined by measuring PP and MLN T cell proliferation and cytokine profile (IL- 2, IFN-y, IL-4 and IL-10 production). Intestinal barrier functions will be measured by determining intestinal permeability and by quantifying translocated bacteria in MLN. In Specific Aim 2 studies using approaches of selective decontamination of intestine with antibiotics prior to EtOH intoxication and burn injury will determine whether intestinal bacteria are critical to IL-18/IL-12-mediated alterations in intestinal immunity and barrier function. Finally, studies in Specific Aim 3 will determine whether Mitogen Activated Protein Kinase (Erk-1/2, p-38, JNK) and/or Signal Transducer and Activator Proteins (STAT-4 and -6) are involved in signaling IL-18/IL- 12-mediated suppression of PP and MLN T cell functions following EtOH intoxication and burn injury. Our studies delineating mechanism of impaired intestinal immunity and barrier function would help in designing approaches for treatment of burn patients who sustained injury under the influence of EtOH intoxication.

描述（由申请人提供）：酒精（EtOH）中毒仍然是烧伤后发病机制的主要因素。我们实验室最近的研究表明，烧伤前急性乙醇中毒会导致：1）肠道淋巴[派尔氏淋巴结（PP）和肠系膜淋巴结（MLN）]T细胞增殖、IL-2和IFN-y产生减少； 2) MLN IL-12 产量减少； 3)增加PP和MLN IL-18的产量； 4）肠道通透性增加； 5) MLN 中细菌积累增加。用 Caspase-1（一种将 pro-IL-18 转化为成熟 IL-18 的酶）抑制剂 Ac-YVAD-CHO (5 mg/kg) 治疗大鼠，可防止 EtOH 和烧伤介导的 MLN 减少IFN-γ的产生和肠水肿的发生。这些初步研究结果共同表明，IL-18 上调和 IL-12 产生减少在乙醇中毒和烧伤后肠道免疫和屏障功能改变中发挥着作用。先前的研究表明，肠道屏障功能受损以及随后细菌及其产物的释放在烧伤后发病机制中发挥着重要作用。因此，拟议研究的总体目标是阐明乙醇中毒和烧伤后肠道免疫和屏障功能受损的机制。我们假设乙醇中毒和烧伤后肠道淋巴器官中不产生 IL-12，而 IL-18 上调，导致肠道免疫力下降和屏障功能受损。使用急性乙醇中毒和烧伤的大鼠模型，特定目标 1 中的研究将表征改变的 IL-18 和 IL-12 的来源（巨噬细胞/树突状细胞），并确定是否通过施用重组 IL-12 单独恢复 IL-12或与通过中和抗IL-18抗体抑制IL-18组合，可防止：1)抑制肠道免疫，以及2)乙醇中毒和烧伤后肠道屏障功能受损。通过测量 PP 和 MLN T 细胞增殖和细胞因子谱（IL-2、IFN-γ、IL-4 和 IL-10 产生）来确定肠道免疫。通过测定肠道通透性和量化 MLN 中易位的细菌来测量肠道屏障功能。在特定目标 2 研究中，在乙醇中毒和烧伤之前使用抗生素选择性净化肠道的方法将确定肠道细菌是否对 IL-18/IL-12 介导的肠道免疫和屏障功能改变至关重要。最后，特定目标 3 中的研究将确定丝裂原激活蛋白激酶（Erk-1/2、p-38、JNK）和/或信号转导蛋白和激活蛋白（STAT-4 和 -6）是否参与 IL-18 信号转导EtOH中毒和烧伤后/IL-12介导的PP和MLN T细胞功能抑制。我们的研究描绘了肠道免疫和屏障功能受损的机制，将有助于设计治疗因乙醇中毒而受伤的烧伤患者的方法。