title: Essential role for IL-2 in the regulation of antiviral extralymphoid CD8 T cell responses.
abstract: IL-2 is a cytokine produced primarily by activated T cells and is thought to be the quintessential T cell growth factor. The precise role of IL-2 in the regulation of CD8 T cell responses to foreign Ag in vivo however remains enigmatic. Using an adoptive transfer system with IL-2- or IL-2R-deficient TCR transgenic CD8 T cells and MHC class I tetramers, we demonstrated that the expansion of antiviral CD8 T cells in secondary lymphoid tissues was IL-2 independent, whereas IL-2 played a more significant role in supporting the continued expansion of these cells within nonlymphoid tissues. Paradoxically, autocrine IL-2 negatively regulated the overall magnitude of the CD8 T cell response in nonlymphoid tissues via a Fas-independent mechanism. Furthermore, autocrine IL-2 did not regulate the contraction or memory phase of the response. These experiments identified a novel role for IL-2 in regulation of antiviral CD8 T cell responses and homeostasis in nonlymphoid tissues.
authors.affiliation: Division of Immunology, Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA.
authors.forename: Warren N
authors.initials: WN
authors.lastname: D'Souza
authors.forename: Kimberly S
authors.initials: KS
authors.lastname: Schluns
authors.forename: David
authors.initials: D
authors.lastname: Masopust
authors.forename: Leo
authors.initials: L
authors.lastname: Lefrançois
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D007156:Immunologic Memory; D007376:Interleukin-2 / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D014777:Virus Diseases / Q000276:immunology*
chemical_list: D007376:Interleukin-2