Hand transplantations have revolutionized the reconstruction field for patients with hand defects. However, immunosuppressants are essential for maintaining human hand transplant survival despite lethal side effects. Recent studies indicate that Mesenchymal stem cells (MSCs) have some immunomodulatory properties to suppress T cell mediate responses that cause tissue rejection. The purpose of this study is to evaluate the effect of intravenous donor MSC infusion for immunomodulation in the rat composite tissue allotransplantation model.
Orthotopic rat hind limb transplantation was performed using donor Wister rats and recipient Lewis rats. The recipient rats were injected intravenously with 2 × 106 donor MSCs on day 6 with 0.2 mg/kg/day tacrolimus administered over 7 days. Graft survival was assessed by daily inspection and histology. Recipients' immunological reactions were also evaluated.
The graft survival was significantly prolonged in comparison with those of control groups. Recipient rats significantly reduced serum pro-inflammatory cytokine. Cytokine expression analysis of the skin of grafted limbs showed that MSC treatment significantly decreased pro-inflammatory cytokine expression.
MSCs induce T cell hyporesponsiveness and prolong graft survival in the rat composite allotransplantation model. MSCs demonstrate some immuno-modulatory properties for transplant rejection that can be accomplished without the need for significant recipient immunosuppression.
