title: Temporal loss of the activated L-selectin-low phenotype for virus-specific CD8+ memory T cells.
abstract: Whether the L-selectin-low (L-sel-lo) phenotype of acutely stimulated CD8+ T cells is a permanent characteristic of long-term memory CTL precursors (p) is addressed for mice primed with an influenza A virus or the murine parainfluenza type 1 virus, Sendai virus. In both cases, many of the splenic CD8+ CTLp gradually lose the predominantly L-sel-lo profile associated with recently generated CTLp populations. The influenza-specific CTLp also tend to revert from the activated alpha 4-integrin-high to the resting alpha 4-integrin-low form. The kinetics of the switch back to the "naive" L-sel-hi phenotype differs for the influenza and Sendai virus models, perhaps reflecting events occurring during the acute phases of these responses. The return to being L-sel-hi is not due to irreversible lymphocyte senescence, because restimulation of this set with the inducing virus in vitro causes most of the cells to become L-sel-lo. Also, despite the time-related drift of these particular memory CTLp to the L-sel-hi state, the size of the total pool of L-sel-lo CD8+ T cells increases with age.
authors.affiliation: Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Tripp
authors.forename: S
authors.initials: S
authors.lastname: Hou
authors.forename: P C
authors.initials: PC
authors.lastname: Doherty
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D005260:Female; D005434:Flow Cytometry; D007156:Immunologic Memory / Q000502:physiology*; D016130:Immunophenotyping; D009980:Influenza A virus / Q000276:immunology; D019041:L-Selectin; D008213:Lymphocyte Activation / Q000276:immunology; D018655:Lymphocyte Count / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D010222:Parainfluenza Virus 1, Human / Q000276:immunology
chemical_list: D015815:Cell Adhesion Molecules; D019041:L-Selectin