IMMUNOLOGICAL ASPECTS OF HEMORRHAGE

出血的免疫学方面

• 批准号: 2178687
• 负责人: IRSHAD H CHAUDRY
• 金额: $ 24.37万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-04-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2178687
• 关键词: Kupffer's cell; T lymphocyte; antigen presentation; cellular immunity; disease /disorder model; flow cytometry; hemorrhage; immunomodulators; immunosuppression; interleukin 1; laboratory mouse; leukocyte activation /transformation; lymphokines; macrophage; natural killer cells

Our studies have demonstrated that hemorrhage produces a marked depression in cell-mediated immunity which persists despite fluid resuscitation and increases susceptibility to sepsis. Preliminary studies indicate that: a) ATP levels (by 31P-NMR) in splenocytes are barely detectable after hemorrhage and remain depressed even 2 hrs after resuscitation; b) hemorrhage increases splenic macrophage (Mphi) intracellular Ca2+ while decreasing the response to stimulant; c) after exposure to hypoxic environment (without hemorrhage), Mphi antigen presentation (AP) function is depressed and PGE2 production is increased. Our hypothesis, therefore, is that hemorrhage produces regional hypoxia which causes cell ATP to decrease, inducing alterations in calcium homeostasis/second messenger systems, translocation of bacteria (i.e. endotoxin release), and stimulation of Kupffer cells to produce inflammatory cytokines. The net results of the above event(s) is increased PGE2 production, which mediates the depression of Mphi (AP and associated processes) and splenocyte function (proliferation and lymphokine generation), producing immunodepression and increasing susceptibility to sepsis. Studies are proposed to determine whether or not: 1) hemorrhage and resuscitation with and without immunomodulation (with agents such as ATP-MgCl2, calcium antagonists, anti-endotoxin, IL-6 or TNF antibodies, chloroquine), as compared to hypoxia, produce alterations in splenocyte and Mphi ATP/calcium levels and PGE2 production; 2) hemorrhage or hypoxia produces alterations in the second messenger system; 3) the alterations in Mphi cytokine production after hemorrhage and resuscitation with and without the above immunomodulators are transcriptional and/or translational in nature. Such studies will determine whether or not the gene expression for TNF and IL-6 is altered after hemorrhage/immunomodulation. Additionally, in situ hybridization will be carried out to localize the cellular compartments of altered cytokine production; and 4) depletion of arachidonic acid stores before hemorrhage using omega-3 fatty acid diet will prevent the depression of Mphi and splenocyte functions following hemorrhage. The use of biochemical, physiological, cellular and molecular biological techniques to determine the mechanism responsible for immunodepression and increased susceptibility to sepsis following hemorrhage and resuscitation should provide useful information for the treatment and care of patients with major blood loss.

我们的研究表明，出血会导致明显的抑郁症 尽管液体复苏和细胞介导的免疫仍持续存在 增加败血症的易感性。 初步研究表明：a) 脾细胞中的 ATP 水平（通过 31P-NMR）在 出血，复苏后 2 小时仍情绪低落； b) 出血增加脾巨噬细胞 (Mphi) 细胞内 Ca2+，同时 减少对兴奋剂的反应； c) 暴露于缺氧环境后 环境（无出血）、Mphi抗原呈递（AP）功能 情绪低落，PGE2 产量增加。 因此，我们的假设是， 是出血造成局部缺氧，导致细胞 ATP 减少，诱导钙稳态/第二信使的改变 系统、细菌移位（即内毒素释放）以及 刺激库普弗细胞产生炎症细胞因子。 网 上述事件的结果是 PGE2 产量增加，从而介导 Mphi（AP 和相关过程）和脾细胞的抑制 功能（增殖和淋巴因子生成），产生 免疫抑制和增加败血症的易感性。 研究是 建议确定是否： 1) 出血和复苏 且无需免疫调节（使用 ATP-MgCl2、钙 拮抗剂、抗内毒素、IL-6 或 TNF 抗体、氯喹），如 与缺氧相比，脾细胞和 Mphi ATP/钙发生变化 水平和 PGE2 产量； 2）出血或缺氧产生改变 在第二信使系统中； 3) Mphi细胞因子的改变 有或没有上述情况下出血和复苏后的生产 免疫调节剂本质上是转录和/或翻译的。 这样的 研究将确定 TNF 和 IL-6 的基因表达是否 出血/免疫调节后发生改变。 另外，现场 将进行杂交以定位细胞区室 改变细胞因子的产生； 4) 花生四烯酸储备的耗尽 出血前使用omega-3脂肪酸饮食可预防抑郁症 出血后 Mphi 和脾细胞功能的影响。 使用 生物化学、生理学、细胞和分子生物学技术 确定导致免疫抑制和增加的机制 出血和复苏后易患败血症 为患者的治疗和护理提供有用的信息 大量失血。