Homeostatic expansion and phenotypic conversion of naïve T cells in response to self peptide/MHC ligands.
Recent data suggest that survival of resting, naïve T cells requires an interaction with self MHC molecules. From analysis of the class I MHC-restricted T cell receptor transgenic strain OT-I, we report a different response. Rather than merely surviving, these T cells proliferated slowly after transfer into T-depleted syngeneic hosts. This expansion required both T cell "space" and expression of normal levels of self class I MHC molecules. Furthermore, we demonstrate that during homeostatic expansion in a suitable environment, naïve phenotype (CD44(low)) OT-I T cells converted to memory phenotype (CD44(med/high)), despite the absence of foreign antigenic stimulation. On the other hand, cells undergoing homeostatic expansion did not acquire cytolytic effector function. The significance of these data for reactivity of T cells with self peptide/MHC ligands and the implications for normal and abnormal T cell homeostasis are discussed.
Kieper
W C
WC
Center for Immunology, Department of Lab Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
Jameson
S C
SC
D019264:Adoptive Transfer; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002455:Cell Division; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006706:Homeostasis; D018960:Hyaluronan Receptors / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology*
D015395:Histocompatibility Antigens Class I; D018960:Hyaluronan Receptors