STAPHYLOCOCCAL TOXINS AND IL8 AND ARDS

葡萄球菌毒素、IL8 和 ARDS

• 批准号: 2609361
• 负责人: EDMUND J MILLER
• 金额: $ 9.23万
• 依托单位: UNIVERSITY OF TEXAS HLTH CTR AT TYLER
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-12-15 至 2001-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2609361
• 关键词: Staphylococcus aureus; adult respiratory distress syndrome; alveolar macrophages; bacterial disease; blood toxicology; clinical research; cytokine receptors; diagnostic respiratory lavage; endoribonucleases; gene targeting; human subject; human tissue; immunocytochemistry; in situ hybridization; inflammation; interleukin 8; laboratory rabbit; lung injury; phlebotomy; polymerase chain reaction; pulmonary edema; ribonuclease H; staphylococcal enterotoxin; staphylococcal exotoxin; thiophosphate

The Adult Respiratory Distress Syndrome (ARDS) which affects approximately 150,000 individuals in the United States annually, is characterized by an acute deterioration of lung function in individuals who are already clinically ill. Several lines of evidence suggest that neutrophils may influence the initiation and /or severity of the acute lung injury. Interleukin-8 (IL-8) is an important mediator of acute inflammation because it is both a chemotactic and activating factor for neutrophils. There are elevated concentrations of IL-9 in the distal airspaces of most patients with ARDS. These elevated IL-8 concentrations are correlated with the number of neutrophils as well as the mortality rate, a correlation not paralleled by total protein concentration in the airspaces. Sepsis is the most common and lethal predisposing clinical condition for ARDS, both Gram-negative and - positive bacteria in the bloodstream are capable of inducing diffuse lung injury. The are significantly higher concentrations of IL-8 in the pulmonary edema fluid of patients with ARDS from sepsis than from ARDS in the absence of sepsis. A significant proportion of patients with ARDS have an underlying S.aureus infection, and at least two toxins from S.aureus can stimulate the production of IL-8 by human alveolar macrophages. In these studies we will determine which cells from the lung environment are able to produce IL-8 in response to staphylococcal toxins. First this will be assessed in vitro using different cell types in culture and analyzing the media for the presence of IL-8 protein and activity. The purified toxin will then be administered intravenously to rabbits (to mimic a S.aureus infection of non-pulmonary origin), and the ability of the toxin to induce an increase in IL-8 accumulation in the alveolar spaces and/or lung injury will be determined. The lungs will then be examined with immunocytochemical and in situ hybridization techniques to determine which cells are stimulated by the toxins to produce IL-8 in vivo. Furthermore, using specific peptide inhibitors of the IL-8 receptors, and antisense oligonucleotide inhibitors of IL-8 production, we will be able to determine the role of IL-8 in the development of the injury. We will then use genetic knockouts in S.aureus to determine if specifically inhibiting the toxin production by the bacteria prevents the bacteria from injuring the lung. These studies will reveal the involvement of staphylococcal toxins and IL-8 in the lung injury associated with ARDS. If there is a causative relationship between IL-08 and ARDS, pharmacological control of the expression and/or function of this important cytokine, using the peptides and oligonucleotides which we have developed, may reduce the greater that 50% mortality rate associated with this syndrome.

成人呼吸窘迫综合征（ARDS）， 美国每年约有15万人， 以个体肺功能的急性恶化为特征 已经有临床症状的人 几条证据表明， 中性粒细胞可能影响急性炎症的发生和/或严重程度， 肺损伤 白细胞介素-8（IL-8）是急性炎症反应的重要介质， 炎症，因为它既是一种趋化因子，也是一种激活因子， 中性粒细胞 远端IL-9浓度升高 大多数ARDS患者的气道。 这些升高的IL-8 浓度与中性粒细胞的数量以及 死亡率，一种不能用总蛋白质证实的相关性， 空气中的浓度。 败血症是最常见和致命的 急性呼吸窘迫综合征（ARDS）的易感临床状况，包括革兰氏阴性和- 血液中的阳性细菌能够诱导弥漫性 肺损伤 IL-8的浓度显著高于对照组。 脓毒症所致ARDS患者的肺水肿液明显高于ARDS患者 在没有败血症的情况下 很大一部分患者 ARDS有潜在的金黄色葡萄球菌感染，至少有两种毒素来自 金黄色葡萄球菌可刺激人肺泡上皮细胞产生IL-8 巨噬细胞 在这些研究中，我们将确定哪些细胞来自 肺环境能够产生IL-8，以响应葡萄球菌 毒素首先，将使用不同的细胞类型进行体外评估 并分析培养基中IL-8蛋白的存在， 活动 然后将纯化的毒素通过静脉注射给 兔（模拟非肺部来源的金黄色葡萄球菌感染）， 该毒素诱导IL-8在小鼠中积累增加的能力 将确定肺泡空间和/或肺损伤。 肺会 用免疫细胞化学和原位杂交方法检测 技术来确定哪些细胞被毒素刺激， 产生IL-8。此外，使用特异性肽抑制剂， IL-8受体和IL-8的反义寡核苷酸抑制剂 生产，我们将能够确定IL-8的作用， 伤害的发展。然后我们将使用基因敲除， 金黄色葡萄球菌，以确定是否特异性抑制毒素的产生， 防止细菌伤害肺部。 这些 研究将揭示葡萄球菌毒素和IL-8参与 与ARDS相关的肺损伤。 如果有使役 IL-08与急性呼吸窘迫综合征的关系， 表达和/或功能的重要细胞因子，使用 肽和寡核苷酸，我们已经开发，可以减少 与此综合征相关的死亡率超过50%。