自异体皮混合移植成活机制中角质形成细胞及细胞因子作用的实验研究

Experimental study on the role of cytokines and keratinocytes in the survival mechanism of auto and allogeneic mixed skin grafting

目的 观察细胞因子及角质形成细胞在自异体皮混合移植成活机制中的作用。 方法建立自异体皮混合移植大鼠模型和人体表皮细胞 淋巴细胞混合培养 (MELC)模型 ,检测大鼠移植术后血清及创面局部组织标本培养上清液中白细胞介素 (IL)1 0的水平 ,观察体外表皮细胞在诱导免疫抑制中的作用。 结果 术后 7d,移植大鼠血清IL 1 0含量为 (2 5 .89± 2 .82 )ng/L,明显高于正常大鼠的 (1 4 .2 0± 2 .4 3)ng/L(P <0.0 5 )。术后 4～ 1 4d,大鼠组织标本培养上清液中IL 1 0含量显著不同(P <0.0 5或 0 .0 1 ) ;术后 2 1、2 8d与正常大鼠比较 ,差异无显著性意义 (P >0.0 5 )。自体表皮细胞、角质形成细胞在MELC体系中的抑制作用与其剂量相关。自体角质形成细胞加入到MELC中 ,辅助性T淋巴细胞 (Th)1分泌的细胞因子谱主要通过IL 1 0介导而抑制Th2细胞因子谱的分泌 ;当加入抗IL 1 0单克隆抗体后该抑制作用消失。 结论 自异体皮混合移植后 ,嵌入自体皮片中的角质形成细胞通过激活Th2使局部IL 1 0水平升高 ,这可能是移植成活的重要原因之一。

Objective To explore the role of cytokines and keratinocytes in the survival mechanism of mixed auto and allogeneic skin grafting. Methods Thirty-six SD rats were employed in the study. The rat model with mixed auto and allogeneic skin grafting and mixed human epithelial and lymphocytic culture (MELC) model were established. The change of IL-10 in the serum and the supernatant of the cultured tissue sample from the local wound was observed after the mixed skin grafting in scalded rats. And the role of epithelium in the induction of immunosuppression in vitro was monitored. Results The serum IL-10 content in the rats with mixed skin grafting (25.89±2.82 ng/L) at 7 postoperative day (POD) was evidently higher than that in normal rats (14.20 ±2.43 ng/L) (P<0.05). The IL-10 content in the culture supernatant of rat tissue samples exhibited evident different during 4-14 PODs (P<0.05-0.01), while which was no difference to that in normal rat on 21st and 28th POD. The inhibiting effects of autologous epithelia and keratinocytes in MELC system were correlated with their dosage. After the adding of autologous keratinocytes to MELC system the cytokines secreted from Th1 could induce the secretion of cytokines from Th2 by IL-10 mediation. This effect could be corrected by the addition of monoclonal antibody of IL-10. Conclusion The keratinocytes inlayed in the autoskin during mixed grafting could increase the local IL-10 level by activating Th2 cells, which might be one of the important reasons of the survival of mixed skin grafting.