The role of regulatory T cells in thymectomy‐induced autoimmune ovarian disease

Problem To evaluate the role of regulatory T (Treg) cells in autoimmune ovarian disease (AOD). Method of study AOD model was set up by thymectomy of BALB/C mice on day 3 (d3tx). The variation of T lymphocyte subsets, especially the Treg cells were analyzed in the peripheral blood, spleen, para-aortic, and inguinal lymph nodes in d3tx mice. The effect of Treg cells on AOD was further evaluated by adoptive transfer of Treg cells into d3tx mice (d3tx+Treg). Results In d3tx mice, the ratio of Treg/CD4+ was significantly increased rapidly from 1st to 2nd week, rapidly declined in 3rd week, then decreased slowly until the 9th week. The CD3+/T lymphocytes and the ratio of CD4+/CD3+ were significantly decreased in the para-aortic and inguinal lymph nodes of d3tx mice, but the ratio of Treg/CD4+ and CD8+/CD3+ were increased simultaneously. In d3tx mice with adoptive transfer of Treg cells (0.5×104~5×105), there was a significant increase in the Treg/CD4+ ratios in the spleen and peripheral blood. AOD score, especially adoptive transferred treg cells from the ovarian lymph nodes was significantly decreased. Oocytes were successfully obtained from d3tx+Treg mice, which could fertilize and develop to embryos normally. Conclusion Treg cells involved in the pathogenesis of AOD. Sufficient numbers of Treg cells can modify AOD in the early phase in d3tx mice.