Prolonged Cardiac Xenograft Survival By Eliminating Natural Killer Cells With Monoclonal Antibody 3.2.3

Objective This study was designed to investigate the effect of natural killer cells in the model of guinea pig-to-rat cardiac xenotransplantation by eliminating natural killer cells in rat with monoclonal antibody 3.2.3 and CVF injection through peripheral vein. The mechanism of rejection in xenotransplantation will be explored in the model.Material and methods Donors(guinea pig) and recipients wear divided randomly into three groups. Group A(Control group): The heart from guinea pig was transplanted into the abdomen of SD rat with no treatment; Group B(CVF group): The recipients were injected with cobra venom factor(CVF) 20μg/kg through peripheral vein 24 hours prior to transplantation; Group C(mAb group): The recipients were injected with monoclonal antibody 3.2.3 100μg in abdomen 24 hours prior to transplantation and CVF was used as Group B; The survival time of grafts, the pathology and cytokine IFN-γwere detected.Results NK cells wear eliminated with monoclonal antibody injection. The grafts in group A showed hyperacute rejection and delayed xenograft rejection wear observed in other groups. And compared with Group C, the rejection in Group B was more severe. And the survival time was 0.56±0.10h; 45.2±2.42h; 53.4±1.98h separately. The ratio of CD8+T cells and CD4+T both increased in Group B and Group C after transplantation but the difference between which was not statistically significant. The cytokine IFN-γalso increased in Group B and Group C and the elimination of NK cells could reduce the rate of increase.Conclusions Natural killer cells can be eliminated with monoclonal antibody by intraperitoneal injection. Elimination of natural killer cells in host can prolong the survival time of graft but fail to overcome delayed xenograft rejection thoroughly.