Why do you think your paper is highly cited?

Because it reveals a cellular mechanism of T cell regulation by the pleiotropic cytokine TGF-beta1 that is central to the understanding of immunoregulation.

 Does it describe a new discovery, methodology, or synthesis of knowledge?

It describes a new discovery in that T cell-produced TGF-beta1 plays an essential role in the control of T cell responses.

 Would you summarize the significance of your paper in layman's terms?

T cells orchestrate the development of immune responses. Our findings reveal a regulatory circuit whereby T cell-produced TGF-beta1 controls T cell responses, which can be exploited for the immunotherapy of diseases mediated by T cells.

 How did you become involved in this research, and were there any problems along the way?

Studies from us and others prior to this research revealed that TGF-beta1 is an important regulator of T cell responses. Therefore, to define the cellular sources of TGF-beta1 involved in T cell regulation was a logical extension of these studies.

 Where do you see your research leading in the future?

Future studies will define the function of TGF-beta1 produced by specific T cell subsets such as regulatory T cells (Treg cells), and the significance of this regulatory pathway in diseases.

Richard A. Flavell
Department of Immunobiology
Howard Hughes Medical Institute
Yale University School of Medicine
New Haven, CT, USA

Keywords: T cell regulation, T cell-produced TGF-beta1, immunoregulation, T cell responses, immune responses, T cell regulation, pleiotropic cytokine TGF-beta1, regulatory T cells, Treg cells.