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.