The Peripheral Blood Mononuclear Cells Derived Dendritic Cell Induced Culture And Function Determine In Vitro After Liver Transplantation

AIM To study the functional status of the dendritic cells derived from PBMC in recipients of liver transplantation who are in HBV clinical clearance state, a comparison of DCs' differences was made in terms of quantity, maturity, phenotypes, expression of immune molecule and stimulating capacities of allogeneic lymphocytes between liver transplant and those of the normal subjects.METHODS To make sure whether or not the DCs of liver transplant were defective and its incorporated representation, the DCs' quantity was counted, its configuration was observe by optical microscope, electric microscope and laser scan confocal microscope, the DCs' capacity of antigen capture and its phenotype was tested by flow cytometric analysis, and the DCs' capacity of stimulating lymphocytes and presenting HBsAg was estimated by the isotype labeled stimulating reactions of allogeneic lymphocytes. RESULTS Under the condition of HBV clinical clearance, the quantities of the dendritic cells induced from precursor cells in liver transplant were significantly lower than those of normal subjects (P<0.05). The shape and the ultra-structure of the recipients' DCs were abnormal, and the maturity was reduced. On the 7th day of cell culturing, the expressions of HLA-DR,CDla, CD83, CD86 molecules on the dendritc cells of liver transplant were significantly lower than those of the normal subjects (P<0.05) , and on 14th day, the expressions of CDla, CD83 were still significantly lower than those of the normal subjects (P<0.05) . There is no difference in the capacity of stimulating the lymphocytes to product anti-HBs in vitro between them, but the DCs' capacities of stimulating the allogeneic lymphocytes and presentating HBsAg were significantly weaker in liver transplant than those of the normal subjects (P<0.05) . By multiple regression analysis, it shows that the DCs' capacity of HBsAg presentation of liver transplant was correlative with the HBV replication status preoperatively, the postoperative time, the protocol of HBV reinfective prophylaxis and the status of PBMC HBVDNA postoperatively. It indicates that the functional status of the dendritic cells derived from peripheral blood of liver transplant is inhibited, e.g. the reduced quantity, the low grade maturation, the abnormity of shape and ultra-stucture, the low expression of immune molecules and the weak capacity of presenting HBsAg.CONCLUSION These functional defects of DCs may be the key reasons, which lead the liver transplant lost the initiative immune potentness toward HBV. And with the postoperative time prolonging and using lamivudine and HBIG persistently, DCs' capacity of HBsAg presentation will be improved. But the active replication of HBV preoperatively, the positive status of PBMC HBVDNA postoperatively and the absence of prophylaxis toward HBV reinfection and hepatitis B recurrence are the negative causes of improvement of DCs' fuction.