Effect Of Intravenous Injection Of Xenogeneic Apoptosis Cells On Immunological Rejection Of Cardiac Xenograft

Objective This study was designed to investigate the effect of intravenous apoptosis cells on the immunological rejection of cardiac xenograft, which through the model of guinea pig to rat abdominal cardiac xenotransplantation. The mechanisms of rejection in xenotransplantation will be explored in the model.Materials and methods The detection of CD4~+CD25~+ regulation T cell : The spleen cells of guinea pig were injected to SD rat intravenously as normol cells,dead cells and apoptotic cells.Every group has 5 rats.After 0,3,7,11,15 days of the injection, CD4~+CD25~+regulation T cell were detected.At the time of the bulk concentration of CD4~+CD25~+regulation T cell reach its top,the heart transplatation were carry out.Interleukin 10(IL-10) and transforming growth factorβ1 (TGF-β1 ) were detected before heart transplantation. Mixed leukomonocyte reaction (MLR):SD rat spleen cell were react cell; The spleen cells of guinea pig(normal cell,deal cell,apoptotic cell) were stimulatal cell.The optical density(OD) of mixed leukomonocyte reaction (MLR) were observed.Heart transplantation: Donor(guniea pig) and recipient (SD rat) were divided randomly into five groups. GroupⅠ(Control group): The heart from guinea pig was transplanted into the abdomen of SD rat.; GroupⅡ(CVF group): the recipients were injected with chinese cobra venom factor(CVF) 40u/kg in abdomen and 24 hours later CVF 60u/kg were injected in vein again just before transplantation,; GroupⅢ(CVF+ live guniea pig cells):the recipients were injected with live guniea pig cells a week before transplantation, chinese cobra venom factor(CVF) 40u/kg were injected in abdomen and 24 hours later CVF 60u/kg were injected in vein again just before transplantation. GroupⅣ(CVF+ dead guniea pig cells):the recipients were injected with dead guniea pig cells a week before transplantation, chinese cobra venom factor(CVF) 40u/kg were injected in abdomen and 24 hours later CVF 60u/kg were injected in vein again just before transplantation. GroupⅤ(CVF~+ apoptosis guniea pig cells):the recipients were injected with apoptosis guniea pig cells a week before transplantation, chinese cobra venom factor(CVF) 40u/kg were injected in abdomen and 24 hours later CVF 60u/kg were injected in vein again just before transplantation. The grafted heart mean survival time (MST), the change of histopathology.Results (1)The quantity of Rat blood CD4+CD25+ T regulatory cells increased obviously as early as 3 days and the levels reached the top after injection 1 wk and the levels returned to normal at 2 wk.(2)The results of xenograft mixed lymphocyte reaction( XMLR) , the stimulating effect:Group apoptotic cell:380.1±10.10;Group normal cell:590.0±12.71,Group dead cell:615.70±49.52.The stimulating effect of group apoptotic cell was much lower than group normal and group dead cell,P<0.05;The stimulating effect of group normal between group dead cell were not different P>0.05;(3)IL-10,TGF-β1,there was not obviously distinction in the concentration of Group betweenⅠandⅢ,Ⅰa ndⅣ,ⅢandⅣ, P>0.05;groupⅤwas much higher than groupⅠ,ⅢandⅣ,P<0.05;(4)The quantity of Rat blood CD4+CD25+ T regulatory cells increased obviously as early as 1 wk and the levels reached the top after injection and the levels returned to normal at 3 wk. (2)MST: GroupⅠ:28.0±14.20min, GroupⅡ:325.60±50.69min,GroupⅢ:360.80±42.47min, GroupⅣ:317.0±33.54min.GroupⅤ: 444.20±31.05min.The MST of GroupⅤwere prolonged than GroupⅡ,groupⅢand GroupⅣ, P<0.05. GroupⅡand groupⅢand GroupⅣand GroupⅤwere prolonged significantly longer than groupⅠ(P<0.05). The MST of GroupⅢ> GroupⅡand GroupⅣ, but P>0.05.Conclusions 1,The method of intravenous apoptosis cells can raise the lever of IL-10,TGF-β1.2,This method can generate CD4+CD25+ T regulatory cells in rats which can regulate the recipient T cells.3,intravenous apoptosis cells can prolong the survival time of xenograft by using Chinese Cobra Venom Factor (CVF) ,but AVR could not be overcomed completely.