Prolongation of skin allograft survival by combined feeding of donor spleen cells and cyclosporine in mice

Abstract

Background Oral immune tolerance is a method for inducing donor-specific immunotolerance and prolonging graft survival. Objectives We studied the effect of feeding donor spleen cells in combination with cyclosporine (CsA) on skin allograft survival in mice. Methods Tail skins from BALB/c ( H-2 d ) female mice were transplanted onto C57BL/6 ( H-2 b ) female mice. The animals were divided into four groups, each with eight mice: group I, untreated controls; group II, treated with spleen cells; group III, treated with CsA; and group IV, treated with spleen cells and CsA. All grafts were inspected daily. Rejection was diagnosed when the graft loss was >80% to 90%. The immune responses of C57BL/6 toward donor mice were examined by delayed-type hypersensitivity (DTH). Results Survival times of allogeneic skin grafts in groups I, II, III, and IV were 9.9 ± 0.6, 13.1 ± 0.6, 14.7 ± 0.9, and 20.0 ± 0.7 days, respectively. When compared with group I, the survival times of groups II, III, and IV were prolonged significantly ( P < .01). The survival time for group IV was prolonged significantly compared with groups II and III ( P < .01). The DTH responses of group IV were decreased significantly in contrast to groups II and III ( P < .01). Conclusions Feeding donor spleen cells prolonged the survival of skin allografts in mice; combination with CsA led to further prolongation of skin allograft survival.