Ethan Shevach: Tregs - ready for the clinic?

Studies over the past 20 years have clearly defined and extensively characterized Foxp3+ T regulatory cells (Tregs) as major players in the control of most aspects of immune responses as well as playing a potential role in non-immunologic sites (fat, muscle). We are now at a point where studies have been/or will be initiated in the clinic using cellular biotherapy with Tregs, augmentation of Treg numbers/function with IL-2, and modulation of Treg function with small molecules and antibodies. Yet, many factors involved in Treg biology remain poorly studied. I will focus this talk on three key issues: 1) control of Treg homeostasis by TCR and co-stimulatory signals; 2) the role of transcription factors in modifying certain Treg functions; and 3) a critical review of suppressor mechanisms used by polyclonal and antigen-specific Tregs.