title: Low-affinity ligands for the TCR drive proliferation of mature CD8+ T cells in lymphopenic hosts.
abstract: In the absence of thymic emigration, the peripheral T cell pool is maintained by division of mature lymphocytes. We have examined the molecular interactions required for peripheral CD8+ T cell expansion in lymphopenic mice without conventional antigenic stimulation. Expansion of CD8+ T cells in lymphopenic hosts was found to be peptide specific. An antagonist peptide known to serve as a ligand for positive selection of these T cells promoted expansion; however, a control peptide that binds the same class I molecule did not. Surprisingly, the cells undergoing proliferation in lymphopenic hosts did not mature to cytotoxic effectors and displayed a partially activated surface phenotype. These data suggest that division of T cells in the periphery of lymphopenic hosts requires specific recognition of self-peptide/MHC complexes, similar to the signal for thymocyte maturation.
authors.affiliation: Department of Immunology and Howard Hughes Medical Institute, University of Washington, Seattle 98195, USA.
authors.forename: A W
authors.initials: AW
authors.lastname: Goldrath
authors.forename: M J
authors.initials: MJ
authors.lastname: Bevan
mesh_terms: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters / Q000502:physiology; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D015395:Histocompatibility Antigens Class I / Q000502:physiology; D016130:Immunophenotyping; D008024:Ligands; D008213:Lymphocyte Activation; D008231:Lymphopenia / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D015375:Receptors, Interleukin-2 / Q000032:analysis
chemical_list: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters; D015395:Histocompatibility Antigens Class I; D008024:Ligands; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2; C073119:TAP1 protein, human; C486171:Tap1 protein, mouse