金黄色葡萄球菌肠毒素B单克隆抗体对烫伤脓毒症大鼠急性肺损伤的影响

目的探讨金黄色葡萄球菌(简称金葡菌)肠毒素B(SEB)单克隆抗体(单抗)对烫伤脓毒症大鼠急性肺损伤的保护作用。方法雄性Wistar大鼠56只随机分为正常对照组(n=10)、烫伤对照组(n=10)、烫伤后金葡菌感染组(n=20)和SEB单克隆抗体(单抗)拮抗组(n=16)。测定肺组织SEB水平、髓过氧化物酶(MPO)活性、肿瘤坏死因子(TNF)-α和干扰素(IFN)-γ表达的改变。结果烫伤后金葡菌脓毒症动物肺脏SEB含量明显升高，伤后2、6h分别为66.85ng/g组织和92.46ng/g组织，与正常对照组(14.26ng/g组织)和烫伤对照组(17.32ng/g组织)相比均为P＜0.01；同时，肺组织MPO活性显著增强，峰值可达7.39U/g组织，与正常对照组(2.09U/g组织)相比P＜0.05。与之相应，肺组织MPO活性显著增强(P<0.05)。同时，局部组织IFN-γ和TNF-α基因及其蛋白质表达明显上调(P<0.05)，并与肺脏SEB含量呈高度正相关(分别为r=0.9207、P=0.0033和r=0.8142、P=0.0258)。SEB单抗早期干预可有效降低肺组织中SEB含量，并显著抑制IFN-γ和TNF-α的产生，肺脏病理改变亦明显减轻。结论SEB单抗干预可抑制IFN-γ和TNF-α等炎症介质的产生，从而显著减轻烫伤后金葡菌对机体的损害。

The protective effect of monoclonal antibody against staphylococcal enterotoxin B on acute lung injury in postburn staphylococcus aureus sepsis

Objective　To investigate the protective effect of monoclonal antibody (MAb) against staphylococcal enterotoxin B (SEB) on acute lung injury in postburn staphylococcus aureus sepsis. Methods　 56 male wistar rats were randomly divided into four groups as follows: normal controls (n=10), scald control group (n=10), postburn sepsis group (n=20) and SEB monoclonal antibody (MAb) treatment group (n=16). Tissue samples from lungs were collected to measure SEB levels and pulmonary myeloperoxidase (MPO) activity. Gene expression and protein levels of tumor necrosis factor-α(TNF-α) and interferon-γ (IFN-γ) were also detected. Results　After thermal injury combined with staphylococcus aureus challenge, SEB levels in lungs were elevated markedly and the MPO activity in lung increased (P<0.05). Meanwhile, pulmonary expressions of IFN-γ and TNF-α were markedly up-regulated (P<0.05), which positively correlated with local SEB levels (r=0.9207, P=0.0033 and r=0.8142, P=0.0258, respectively). Early Treatment with MAb against SEB, however, could significantlydecrease SEB, IFN-γ as well as TNF-α levels in lungs, and attenuate the acute lung injury. Conclusion　SEB might play an important role in the pathogenesis of acute lung injury in rats with postburn staphylococcus aureus sepsis. A specific monoclonal antibody to SEB-MAb 2D1 appears to be effective in ameliorating acute lung injury, which might be associated with its inhibitory effect on proinflammatory cytokine formation.