Immunosuppressive regulatory T lymphocytes (Treg) expressing the transcription factor Foxp3 play a vital role in the maintenance of tolerance of the immune-system to self and innocuous non-self. Most Treg that are critical for the maintenance of tolerance to self, develop as an independent T-cell lineage from common T cell precursors in the thymus. In this organ, their differentiation requires signals from the T cell receptor for antigen, from co-stimulatory molecules, as well as from cytokine-receptors. Here we focus on the cytokines implicated in thymic development of Treg, with a particular emphasis on the roles of interleukin-2 (IL-2) and IL-15. The more recently appreciated involvement of TGF-β in thymic Treg development is also briefly discussed. Finally, we discuss how cytokine-dependence of Treg development allows for temporal, quantitative, and potentially qualitative modulation of this process.
Animals ; Cell Differentiation ; genetics ; Cytokines ; immunology ; Forkhead Transcription Factors ; genetics ; immunology ; Gene Expression Regulation ; Immune Tolerance ; genetics ; Interleukin-15 ; genetics ; immunology ; Interleukin-2 ; genetics ; immunology ; Mice ; Receptors, Antigen, T-Cell ; genetics ; immunology ; T-Lymphocytes, Regulatory ; immunology ; Transforming Growth Factor beta ; genetics ; immunology