Infusion of recipient alternative activated dendritic cells loaded with trophoblastic cells antigen prolonged survival of heart allografts

Abstract

Objective To investigate the effect of recipient alternative activated dendritic cells (aaDC) loaded with trophoblastic cells antigen (TbC-Ag) on murine cardiac allograft survival Methods Female Balb/c mice were caged and mated with male C57BL/6 mice, then trophoblastic cells were obtained and its antigen was extracted. After co-cultured with TbC-Ag or spleen cells antigen of C57BL/6 mice (SC-Ag), aaDC of Balb/c mice became into TbC-Ag aaDC or SC-Ag aaDC. Concentrations of IL-10 and IL-12 in the culture and expression of CD40, CD80, CD86 and MHC-Ⅱ by aaDC loaded with antigen were detected. At 7th day after Balb/c recipients were intravenously injected with TbC-Ag aaDC (TbC-Ag group) or SC-Ag aaDC (SC-Ag group) or normal saline (control group), heterotopic vascularized heart transplantation was performed from C57BL/6 to BALB/c mice. As third donor group, heterotopic vascularized heart transplantation was performed from Kunming mice to BALB/c mice injected with TbC-Ag aaDC. The cardiac allograft survival time was compared. The expression of of IL-2, IL-10 and IFN-γ, mRNA in heart grafts and recipient spleen cells was detected by RT-PCR. Results The expression of CD86 and MHC-Ⅱ by SC-Ag aaDC was elevated, while only expression of MHC-Ⅱ by TbC-Ag aaDC was elevated. In the culture of TC-Ag aaDC, concentrations of IL-10 and IL-12 were (122.6±15.4) and (232.8±25.4) ng/L, while those of control group were (35.4±8.5) and (267.3±12.5) ng/L, respectively. There was significant difference in the IL-10 concentration (P 0.05) between two groups. There were no significant differences in IL-10 and IL-12 concentrations between SC-Ag aaDC and blank control groups (P>0.05). The cardiac allograft survival time was (6.73± 0.58) days in control group, (12.28±0.76) days in SC-Ag group, (38.83±2.79) days in TbC-Ag group, and (6.68±0.62) days in third donor group, respectively. The survival time in TbC-Ag group was significantly longer than that in control and SC-Ag groups (P 0.05). Conclusion Infusion of TbC-Ag aaDC results in prolonged survival of a completely MHC-mismatched heart allograft. Key words: Dendritic cells; Heart transplantation; Trophoblasts; Antigens