RESUMO
Objective To investigate the role of CTLA4-Ig and anti-CD40L monoclonal antibody in the acute rejection of pancreaticoduodenal transplantation model of rats.Methods Pancreaticoduo- denal transplantation model was established from the donor F344 rats to the Lewis recipients(diabetes models).The models were divided into 4 groups:groups A,B,C and D with 12 rats in each group. Two days after transplantation,recipients were injected intraperitoneally with saline,CTLA4-Ig(200?g),anti-CD40L monoclonal antibody(200?g),CTLA4-Ig(200?g)combined with anti-CD40L monoclonal antibody(200?g)respectively.On the day 1,4,7,10 after transplantation,the grafts were harvested for histopathological examination and RT-PCR to determine the levels of interleukin (IL)-2,interferon(IFN)-?,IL-4 and IL-10;The blood CD3~+,CD4~+and CD8~+ T cells were detected by flow cytometry.On the day 4 after transplantation,the CD4~+ CD25~+ T cells in the grafts were de- tected by flow cytometry.Results As compared with group A,the severity of the rejection of grafts in groups B,C and D were depressed;Down-regulation of IL-2 was observed in the groups B,C and D, and the levels in group D were lowest.Down-regulation of IFN-7 was detected in the groups B,C and D,but there was no significantly difference between groups D and B or groups D and C.Up-regulation of IL-4 was observed in the groups B and C,and the levels in group D were lower than in groups A,B and C.Up-regulation of IL-10 was observed in groups B and C,and there was significant difference between groups D and B or groups D and C.The CD3~+,CD4~+ and CD8~+ T cells in groups B,C and D were less,but more CID4~+ CD25~+ T ceils in transplanted pancreas were observed,more notably in group D than in group C.Conclusions Combined use of CTLA4-Ig and anti-CD40L monoclonal anti- body can remarkably diminish the severity of the rejection,which might be mediated by altering the balance in Th1/Th2 and increasing the number of CD4~+ CD25~+ regulatory T cells.Co-stimulation blockade with CTLA4-Ig and anti-CD40L monoclonal antibody induction seems to be an attractive strategy to control allograft rejection.