Cellular events associated with autoimmune oophoritis and ovarian tumorigenesis in neonatally thymectomized mice

Thymectomy at 3 days of age (Tx-3) in (C3H/HeMs x 129/J)F1 (C31) female mice results in post-pubertal ovarian dysgenesis associated with high levels of circulating auto-oocyte antibodies (AOA) prior to ovarian tumor formation. Evidence suggests that the etiology for the ovarian dysgenesis resulting from Tx-3 is autoimmune and involves helper T cell abnormalities. The present study characterized circulating leukocytes and mitogenic activity using concanavalin A (ConA) with serologically selected spleen T cells. We observed no sustained abnormalities in either number of circulating leukocytes or percentages of granulocytes or lymphocytes. Circulating mononuclear cells with positive immunofluorescence for Thy 1.2 and Lyt 1.1+Lyt 1.2 cell markers were similar in all mice. However, the spleen cells from Tx-3 mice with ovarian dysgenesis remaining after adsorption with antisera to the Lyt 2.1+Lyt 2.2 antigens (helper T cells remaining) showed increased incorporation of [3H]thymidine compared to the intact mice. This stimulated activity occurred during the periods of early ovarian dysgenesis and active tumor growth. Apparently, the autoimmune oophoritis results from an imbalance within the Lyt 1 cells which may represent a primary insult to the ovary that results in later ovarian tumor development.