Authors:
Ann M. Davis, Hilario J. Ramos, Laurie S. Davis, and J. David Farrar
Summary:
IL-2 is a hallmark cytokine secreted by central memory CD4+ T cells (TCM). Although naive cells rapidly secrete IL-2 in response to Ag stimulation, IL-12 inhibits IL-2 secretion in daughter cells as they differentiate into Th1 cells. In this study, we uncover a unique role for IFN- in regulating IL-2 secretion by human TCM cells. IFN- synergized with IL-12 to enhance a subset of cells that secreted high and sustained levels of IL-2. These IL-2-secreting cells displayed phenotypic and functional characteristics of TCM and were capable of generating IFN- -secreting effectors upon secondary activation. T-bet has been implicated in negatively regulating IL-2 secretion in murine T cells; however, T-bet expression did not inhibit IFN- -dependent IL-2 secretion in human TCM cells. Thus, our results highlight a unique role for IFN- in regulating the development of IL-2-secreting human TCM cells.
Source:
Journal of Immunolgy; 181, 8204-8208 (2008)