Schwacha M G, Knöferl M W, Chaudry I H
Center for Surgical Research, Department of Surgery, University of Alabama at Birmingham, 35294-0019, USA.
Shock. 2000 Dec;14(6):623-8. doi: 10.1097/00024382-200014060-00009.
Studies have shown that cell mediated immunity is suppressed markedly following thermal injury. Macrophages and the activation of an inflammatory cascade that includes interleukin (IL)-1, IL-6, tumor necrosis factor-alpha (TNFalpha) and PGE2 have been implicated as causative factors. Burn wound excision and grafting is a common clinical practice that decreases patient morbidity and mortality. It is not known, however, if the salutary effects of this procedure are related to modulation of macrophage activity post-burn. Therefore, C57BL/6 female mice were subjected to a third-degree scald burn covering 25% of their total body surface area followed by complete excision and allografting of the injury site at 8, 24, or 72 h post-burn. Splenic macrophage function was assessed 7 days post-burn. Thermal injury without burn excision and grafting significantly increased macrophage TNFalpha, IL-6, nitric oxide, and PGE2 production in response to lipopolysaccharide stimulation, whereas IL-1beta production was not increased. Burn wound excision and grafting normalized TNFalpha production to sham levels, independent of when post-burn the procedure was conducted. In contrast, the elevated production of other inflammatory mediators (IL-1beta, IL-6, nitric oxide, PGE2) post-burn was unaffected by burn wound excision and grafting. Moreover, splenic T-lymphocyte proliferation was also suppressed at 7 days post-burn and was not improved by burn wound excision and grafting. These results, therefore, suggest that the beneficial effects of burn wound excision and grafting are likely to be related to the normalization of macrophage TNFalpha production as well as the maintenance of skin barrier function.
研究表明,热损伤后细胞介导的免疫会受到显著抑制。巨噬细胞以及包括白细胞介素(IL)-1、IL-6、肿瘤坏死因子-α(TNFα)和前列腺素E2在内的炎症级联反应的激活被认为是致病因素。烧伤创面切除和植皮是一种常见的临床操作,可降低患者的发病率和死亡率。然而,尚不清楚该手术的有益效果是否与烧伤后巨噬细胞活性的调节有关。因此,对C57BL/6雌性小鼠进行占其全身表面积25%的三度烫伤,然后在烧伤后8、24或72小时对损伤部位进行完全切除和同种异体移植。在烧伤后7天评估脾巨噬细胞功能。未进行烧伤切除和植皮的热损伤显著增加了巨噬细胞对脂多糖刺激的TNFα、IL-6、一氧化氮和前列腺素E2的产生,而IL-1β的产生并未增加。烧伤创面切除和植皮使TNFα的产生恢复到假手术水平,与烧伤后何时进行该手术无关。相比之下,烧伤后其他炎症介质(IL-1β、IL-6、一氧化氮、前列腺素E2)的产生增加不受烧伤创面切除和植皮的影响。此外,烧伤后7天脾T淋巴细胞增殖也受到抑制,烧伤创面切除和植皮并未改善这种情况。因此,这些结果表明,烧伤创面切除和植皮的有益效果可能与巨噬细胞TNFα产生的正常化以及皮肤屏障功能的维持有关。