ABSTRACT
<p><b>BACKGROUND</b>Previous studies showed that anti MHC-II monoclone antibody (MAb) only had partial inhibiting effect of alloreactive mixed lymphocyte reaction (MLR) in vitro and it was unsteady and non-persistent. The aim of this research was to determine whether radioactive isotope (188)Re marked MHC-II antibody could benefit the allograft acceptance in transplantation as compared to normal MHC-II antibody.</p><p><b>METHODS</b>188Re was incorporated to 2E9/13F (ab')(2) which is against swine MHC class II antigen (MAb-(188)Re). Porcine peripheral blood mononuclear (PBMC) cells were examined for proliferation and cytokine mRNA expression after stimulation with MHC-II MAb or MAb-(188)Re.</p><p><b>RESULTS</b>The proliferative response of recipient PBMCs in mixed lymphocyte reaction (MLR) to donor alloantigen showed that the stimulation index of MAb-(188)Re group was significantly lower than the MHC-II MAb group and control (P < 0.05). mRNA expression of interleukin 2, interferon Υ and tumor necrosis factor α (type 1 cytokines) was lower in MAb-(188)Re group than the MHC-II MAb group, while interleukin 10 (type 2 cytokines) was higher in MAb-(188)Re group in the first 24 hours.</p><p><b>CONCLUSION</b>MAb-(188)Re could help the graft acceptance by inhibiting T cell proliferation, lowering the expression of type 1 cytokines and elevating the type 2 cytokines produced by PBMC.</p>