Estrogen receptor α contributes to T cell-mediated autoimmune inflammation by promoting T cell activation and proliferation.

It has long been appreciated that most autoimmune disorders are characterized by increased prevalence in females, suggesting a potential role for sex hormones in the etiology of autoimmunity. To study how estrogen receptor α (ERα) contributes to autoimmune diseases, we generated mice in which ERα was deleted specifically in T lymphocytes. We found that ERα deletion in T cells reduced their pathogenic potential in a mouse model of colitis and correlated with transcriptomic changes that affected T cell activation. ERα deletion in T cells contributed to multiple aspects of T cell function, including reducing T cell activation and proliferation and increasing the expression of Foxp3, which encodes a critical transcription factor for the differentiation and function of regulatory T cells. Thus, these data demonstrate that ERα in T cells plays an important role in inflammation and suggest that ERα-targeted immunotherapies could be used to treat autoimmune disorders.