抗内毒素单抗对脓毒症小鼠胸腺细胞凋亡及白介素1β-转换酶基因表达的影响

Effects of anti-endotoxin monoclonal antibody on thymocytes apoptosis and expression of interleukin-1β-conventing enzyme in septic mice

目的探讨胸腺细胞凋亡在小鼠脓毒症机制中的作用,观察抗内毒素单抗对胸腺细胞内胸腺细胞凋亡相关基因白介素1β-转换酶(ICE)表达的影响。方法盲肠结扎穿孔(CLP)造成小鼠脓毒症,假手术组接受同样的手术操作但不行CLP,治疗组在术前2小时腹腔内注射抗内毒素单抗4mg/kg,致伤后1、3、6小时取胸腺组织,采用RT-PCR定量检测ICE基因表达。结果抗内毒素单抗明显减少了胸腺细胞凋亡的数量并且下调了ICE基因的表达(P<0.01);改善了小鼠的存活率。结论脓毒症使胸腺细胞大量凋亡并诱导了ICE基因表达增强,抗内毒素单抗有效抑制了ICE基因的表达,减少了胸腺细胞凋亡,提高了小鼠的存活率,提示ICE基因参与了胸腺细胞凋亡机制。

Objective To investigate the role of thymocytes apoptosis and the effects of anti-LPS mAb treat ment on the number of thymocyte apoptosis and expression of interleukin-1 β-conventing enzyme (ICE) m RNA in septic mice. Methods Sepsis were induced in mice by cecal ligation and puncture (CLP). Sham-operation group underwent the same manipulation but without CLP treatment. The treated mice were intraperitoneally given anti-LPS mAb at 2 h prior to CLP. Thymocytes apoptosis were assessed quantitatively by FCM and biochemically by DNA gel electrophoresis. Results Sepsis markedly induced ICE gene overexpression and thymocytes apoptosis. The number of thymic apoptotic cells was obviously correlated with the level of ICE mRNA expression. Anti-LPS mAb treatment significantly improved the animals survival (7/10 vs 1/10) and inhibited ICR mRNA expression and decreased thymocyte apoptosis (P<0.01). Conclusion The phenomenon of thymocytes apoptosis was related to stress induction. ICE mRNA overexpression might be involved in the vulnerability of thymocytes to apoptosis. Interruption of the inflammatory cascade with anti-LPS mAb at the inducer level can effectively reduce thymocytes apoptosis, thus ameliorate immunodepression.