Oestrogen, an evolutionary conserved regulator of T cell differentiation and immune tolerance in jawed vertebrates?
In teleosts, as in mammals, the immune system is tightly regulated by sexual steroid hormones, such as oestrogens. We investigated the effects of 17β-oestradiol on the expression of several genes related to T cell development and resulting T cell subpopulations in sea bass, Dicentrarchus labrax, for a primary lymphoid organ, the thymus, and two secondary lymphoid organs, the head-kidney and the spleen. In parallel, the oxidative burst capacity was assessed in leucocytes of the secondary lymphoid organs. Apoptosis- and proliferation-related genes, indicative of B and T cell clonal selection and lymphoid progenitor activity, were not affected by elevated oestrogen-levels. Sex-related oestrogen-responsiveness in T cell and antigen-presenting cell markers was observed, the expression of which was differentially induced by oestrogen-exposure in the three lymphoid organs. Remarkably, in the spleen, oestrogen increased regulatory T cell-related gene expression was associated with a decrease in oxidative burst capacity. To the best of our knowledge, this study indicates for the first time that physiological levels of oestrogen are likely to promote immune tolerance by modulating thymic function (i.e., T cell development and output) and peripheral T cells in teleosts, similar to previously reported oestrogenic effects in mammals.
['Paiola|Matthieu|M|', 'Knigge|Thomas|T|', 'Duflot|Aurélie|A|', 'Pinto|Patricia I S|PIS|', 'Farcy|Emilie|E|', 'Monsinjon|Tiphaine|T|']
D000818:Animals D000938:Antigen-Presenting Cells D001402:B-Lymphocytes D001492:Bass D002454:Cell Differentiation D017637:Clonal Deletion D004967:Estrogens D019143:Evolution, Molecular D005260:Female D007108:Immune Tolerance D008213:Lymphocyte Activation D008297:Male D012723:Sex D016176:T-Lymphocyte Subsets D050378:T-Lymphocytes, Regulatory
Teleost Thymus Head-kidney Spleen Gamma-delta T cell Regulatory T cell