The discovery of an inhibitory signaling circuit that blocks the generation and function of regulatory T cells is reported online in Nature Immunology.
Regulatory T cells prevent the development of autoimmune diseases, such as diabetes, by suppressing unwanted immune responses.
Hongbo Chi and colleagues identify the receptor S1P1 as the crucial inhibitor to these regulatory T cells. Mice lacking S1P1 display an increased number of regulatory T cells and these cells are more suppressive.Conversely, mice overexpressing S1P1 develop autoimmunity as a result of severely diminished number of regulatory T cells.
These results may have clinical importance as presently there are trials underway to manipulate S1P1 function for another reason. The new work broadens the list of activities attributed to S1P1, and identifies the unique sensitivity of regulatory T cells to signaling via this receptor.