Establishment Of Specific Immunological Tolerance Model For Rabbit By Bone Marrow Transplantation

[Objective]To investigate the feasibility and practicability of establishing model of specific immunological tolerance using total body irradiation(TBI) and bone marrow transplantation(BMT) for rabbits. [Methods]Thirty male and thirty female New Zealand rabbits were respectively used as donors and recipients,matched pairs to them randomly.Thirty pair rabbits were divided randomly into 5 groups,including blank control group,simple TBI group,simple BMT group,experimental group (TBI+BMT) and third party donor control group,with 6 pair of rabbits in each group.Before the BMT ,TBI(7Gy)was performed in recipient rabbits.24 hours after TBI,the bone marrow cells were injected through the oto-edge vein.On posttransplant day 5,the bone marrow cells from the same donor were injected again,meanwhile,skin grafting was performed .The total number that bone marrow cells were injected was 1～1.5×108/kg.The survival time of skin grafts,reject reaction against the third party skin,and mixed lymphocyte reaction (MLR) were observed.The polymerase chain reaction (PCR) was employed for the detection of chimerism. [Result]Simple BMT or TBI led to neither prolonged survival time of grates nor the formation of chimerism.The skin graft survival time was significantly prolonged in the experimental group (45.83 ±3.97d),as compared with the blank control group (10.83±0.75),the TBI group(12.5±1.0488),the BMT group(11.33±0.8165 ) and the third party donor control group ( 12.17 ±1.169 ) ,respectively (P<0.01) .MLR demonstrated that the donor specific inhibition of lymphocyte proliferation in the experimental group was induced. Chimerism developed in the experimental group. [Conclusions](1) For rabbit, the precondition of 7Gy total body irradiation for BMT is nonmyeloablative.(2) BMT with nonmyeloablative precondition method may induce certain extent of immunological tolerance and prolong the survival time of rabbit skin graft.(3)Using PCR technology to definite the existence of purpose genetic fragment in sex-determining region of Y choromosome characteristic of male rabbit is a convenient method for detecting the mixed chimerism.