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

ABSTRACT

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 x 10(6))CD4+CD25+ Treg was transfused to rat CTA model. Collected peripheral blood 30 days after operation, and used nylon wool column to separate B cell and T cell. With the stimulation of IgM, detected B cell proliferation and the level of IgG and IgA in serum. Observed the effect of CD4+CD25+ Treg on B cell and T cell function and the survival 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-intervention 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-intervention group were (2418 +/- 348), (2252 +/- 127), (2315 +/- 218) and (3720 +/- 224), there was a significant difference in these groups (P < 0.01). The serum level of IgG and IgA of topical intervention group and systemic intervention group were (12.56 +/- 1.30), (2.38 +/- 0.21), (13.48 +/- 1.23) and (2.86 +/- 0.24) g/L, and of normal control group was (12.35 +/- 1.28), (2.36 +/- 0.12) g/L, had no significant difference (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.