ESTROGEN-TREATMENT DEPLETES EXTRATHYMIC T-CELLS FROM INTESTINAL LYMPHOID-TISSUES

Different lineages of thymic and extrathymic T cells are found in the epithelial layer and in the lamina propria of the small and large inte stine of euthymic and athymic mice. A single subcutaneous injection of oestradiolvalorat (Progynon(R)-Depot-10, Schering, Berlin, Germany) i nto athymic mice led to a dose-dependent depletion of extrathymic T ce lls from the intraepithelial and lamina propria compartments of the sm all and large intestine. TCR alpha beta and TCR gamma delta, CD4(+) an d CD8 alpha(+) T cell subsets were affected. The depletion of intraepi thelial, extrathymic T cells by oestradiol treatment was striking. Oes trogen, therefore, has an effect not only on genital mucous membranes, but also on the large, diffuse lymphoid tissues of the gut, in that i t selectively depletes the intestinal, extrathymic T-cell subsets.