Song G Y, Chung C S, Chaudry I H, Ayala A
Division of Surgical Research and Department of Surgery, Brown University School of Medicine and Rhode Island Hospital, Providence, Rhode Island 02903, USA.
Am J Physiol Cell Physiol. 2001 Aug;281(2):C662-9. doi: 10.1152/ajpcell.2001.281.2.C662.
Although studies indicate that a shift from a Th1 to a Th2 response contributes to a marked suppression of cell-mediated immunity during sepsis, the mechanism by which this occurs remains unknown. Given that the mitogen-activated protein kinase (MAPK) p38 plays a critical role in the activation and function of immune cells, the aim of this study was to determine the contribution of MAPK p38 activation to the immune dysfunction seen in polymicrobial sepsis. To study this, polymicrobial sepsis was induced in C3H/HeN male mice by cecal ligation and puncture (CLP). Splenic lymphocytes and purified T cells were harvested 24 h post-CLP, pretreated with the specific MAPK p38 inhibitor SB-203580, and then stimulated with a monoclonal antibody against the T cell marker CD3. The results indicate that interleukin (IL)-2 release is markedly depressed while the release of the immunosuppressive mediator, IL-10, as well as mRNA levels of IL-10 and IL-4, are augmented after CLP. Inhibition of MAPK p38 suppressed in vitro IL-10 levels as well as IL-10 and IL-4 gene expression while restoring the release of IL-2. To determine whether these in vitro findings could be translated to an in vivo setting, mice were given 100 mg of SB-203580/kg body wt or saline vehicle (intraperitoneal) at 12 h post-CLP. Examination of ex vivo lymphocyte responsiveness indicated that, as with the in vitro finding, septic mouse Th1 responsiveness was restored. In light of our recent finding that delayed in vivo SB-203580 treatment also improved survival after CLP, we believe that these results not only illustrate the role of MAPK p38 in the induction of immunosuppressive agents in sepsis but demonstrate that SB-203580 administration after the initial proinflammatory state of sepsis significantly prevents the morbidity from sepsis.
尽管研究表明，在脓毒症期间从Th1反应向Th2反应的转变会导致细胞介导的免疫显著抑制，但其发生机制仍不清楚。鉴于丝裂原活化蛋白激酶（MAPK）p38在免疫细胞的激活和功能中起关键作用，本研究的目的是确定MAPK p38激活在多微生物脓毒症中所见免疫功能障碍中的作用。为了研究这一点，通过盲肠结扎和穿刺（CLP）在C3H/HeN雄性小鼠中诱导多微生物脓毒症。CLP后24小时收集脾淋巴细胞和纯化的T细胞，用特异性MAPK p38抑制剂SB-203580预处理，然后用抗T细胞标志物CD3的单克隆抗体刺激。结果表明，CLP后白细胞介素（IL）-2释放明显降低，而免疫抑制介质IL-10的释放以及IL-10和IL-4的mRNA水平升高。抑制MAPK p38可抑制体外IL-10水平以及IL-10和IL-4基因表达，同时恢复IL-2的释放。为了确定这些体外研究结果是否可以转化为体内情况，在CLP后12小时给小鼠腹腔注射100 mg/kg体重的SB-203580或生理盐水载体。对离体淋巴细胞反应性的检查表明，与体外研究结果一样，脓毒症小鼠的Th1反应性得到恢复。鉴于我们最近的发现，即体内延迟给予SB-203580也可改善CLP后的生存率，我们认为这些结果不仅说明了MAPK p38在脓毒症中诱导免疫抑制剂的作用，而且证明了在脓毒症初始促炎状态后给予SB-203580可显著预防脓毒症的发病。
