[Study on the effect of CD4+CD25+ regulatory T cell adoptive transfusion on humoral immune function in rat composite tissue allotransplantation model].

Objective To approach the effect of the donor antigenic specificity CD4~+ CD25~+ regulatory T cell(Treg) on cellular immune tolerance function in rat composite tissue allotransplantation (CTA).Methods Use the method of immunomagnetic beads to separate CD4~+CD25~+ Treg.(1×10°) CD4~+ CD25~+ Treg was transfused to rat CTA model.Collected pefipheral blood 30 days after operation.and used nylon WooI column to separate B cell and T cell.With the stimulation of IgM.detected B cell proliferation and the level of IgG and lgA in serum Observed the effect of CD4~+ CD25~+Treg on B cell and T cell function and the survial of allotransplants,and analyzed the data by statistics.Results The purity of separated CD4~+ CD25~+ Treg was 95.6%.The CPM of T cell of normal control group.topical intervention group,systemic intervention group and non-interventiom group were(2436±358),(2273±136),(2338± 228)and(3749±245).The CPM of B cells of normal control group,topical intervention group.systemic intervention group and non-interventiom group were(2418±348),(2252±127),(2315±218) and (3720±224),there was a significant difference in these groups (P 0.05).But Treg of non-intervention group was (16.58± 1.12),(3.75±0.37)g/L,there was a significant difference in the non-intervention group and the three above groups(P<0.01).The survival time of CTA in intervention of local and systemic groups were (97±13)and(63±10)d,which were significant longer than the non-intervention group[(22±8)d,P< 0.01].Conclusions Donor antigen specific CD4~+ CD25~+ Treg has significantly inhibited B cell and T cell function.It can induce immune tolerance and extend the survival time of CTA:as well local application iS better than systemic. Key words: T-lymphocytes,regulatory; Transplantation,homologous; Surgical flaps; Graft enhancement,immunologic