嗜中性粒细胞通过分泌IL-22促进结肠上皮细胞的修复研究

Study on neutrophils contribute the reparation of colonic epithelial cells via IL-22 production

目的探讨嗜中性粒细胞通过分泌白介素-22(Interleukin-22,IL-22)刺激肠道上皮细胞分泌黏液蛋白的作用。方法分离小鼠骨髓来源的嗜中性粒细胞,不同浓度的IL-23刺激中性粒细胞,检测IL-22 mRNA及蛋白合成;收集经IL-23刺激后中性粒细胞上清,将其作为条件培养基培养小鼠肠道上皮细胞CMT-93,检测CMT-93合成Reg3及MUC2的变化,并用IL-22中和抗体验证IL-22是否在条件培养基中起主要作用。结果 50 ng/ml IL-23即可显著诱导嗜中性粒细胞合成IL-22 mRNA,ELISA检测培养6 h的嗜中性粒细胞上清,IL-22蛋白量为(92±19)pg/ml。条件培养基培养CMT-93细胞24 h,Reg3和MUC2的mRNA合成倍数与对照组相比分别上升(11±3)和(14±5)倍,与单用IL-22诱导无显著差异,但使用IL-22阻断抗体后,条件培养基诱导CMT-93细胞合成抗菌肽的倍数分别降低至(2.4±0.8)和(2.1±0.5)倍。结论嗜中性粒细胞通过分泌细胞因子IL-22在促进肠道上皮细胞分泌抗菌肽中起重要作用。

Objective To investigate the up-regulation of mucin by IL-22 produced by neutrophils in mouse colonic epithelial reparation. Methods IL-23 stimulated mouse bone marrow derived neutrophils, the mRNA and protein levels of IL-22 production were measured;the supernatant of neutrophils treated with IL-23 was collected, mouse colonic epithelial ceils CMT-93 with this conditional culture medium was administrated, the synthesis of Reg3 and MUC2 mRNA level were detected. Furthermore, [L-22-blocking antibody to neutralize IL-22 in the conditional culture medium was used, the Reg3 and MUC2 mRNA levels were observed. Results IL-22 mRNA level was significantly enhanced by IL- 23 treatment, the production of IL-22 protein was （92 ± 19） pg/ml at 6 h after IL-23 treatment. The mRNA fold of Reg3 and MUC2 in CMT-93 cells were markedly up-regulated by neutrophils-conditional culture medium compared with control group, which were（ 11 ± 3） and （ 14 ± 5） respectively, however, with [L-22-blocking antibody treatment, the mRNA fold of Reg3 and MUC2 in CMT-93 cells was decreased to （2.4 ± 0.8） and （2.1 ± 0.5）. Conclusion IL-22- producing neutrophils may play a critical role in mouse colonic epithelial cells production of antimicrobial mucin.