Regulatory Function of a Novel Population of Mouse Autoantigen-Specific Foxp3− Regulatory T Cells Depends on IFN-γ, NO, and Contact with Target Cells

Background Both naturally arising Foxp3+ and antigen-induced Foxp3− regulatory T cells (Treg) play a critical role in regulating immune responses, as well as in preventing autoimmune diseases and graft rejection. It is known that antigen-specific Treg are more potent than polyclonal Treg in suppressing pathogenic immune responses that cause autoimmunity and inflammation. However, difficulty in identifying and isolating a sufficient number of antigen-specific Treg has limited their use in research to elucidate the mechanisms underlying their regulatory function and their potential role in therapy.