title: In vivo compartmentalization of functionally distinct, rapidly responsive antigen-specific T-cell populations in DNA-immunized or Salmonella enterica serovar Typhimurium-infected mice.
abstract: The location and functional properties of antigen-specific memory T-cell populations in lymphoid and nonlymphoid compartments following DNA immunization or infection with Salmonella were investigated. Epitope-specific CD8+ -T-cell expansion and retention during the memory phase were analyzed for DNA-immunized mice by use of a 5-h peptide restimulation assay. These data revealed that epitope-specific gamma interferon (IFN-gamma)-positive CD8+ T cells occur at higher frequencies in the spleen, liver, and blood than in draining or peripheral lymph nodes during the expansion phase. Moreover, this distribution is maintained into long-term memory. The location and function of both CD4+ and CD8+ Salmonella-specific memory T cells in mice who were given a single dose of Salmonella enterica serovar Typhimurium was also quantitated by an ex vivo restimulation with bacterial lysate to detect the total Salmonella-specific memory pool. Mice immunized up to 6 months previously with S. enterica serovar Typhimurium had bacterium-specific CD4+ T cells that were capable of producing IFN-gamma or tumor necrosis factor alpha (TNF-alpha) at each site analyzed. Similar findings were observed for CD8+ T cells that were capable of producing IFN-gamma, while a much lower frequency and more restricted distribution were associated with TNF-alpha-producing CD8+ T cells. This study is the first to assess the frequencies, locations, and functions of both CD4+ and CD8+ memory T-cell populations in the same Salmonella-infected individuals and demonstrates the organ-specific functional compartmentalization of memory T cells after Salmonella infection.
authors.affiliation: Department of Cell and Molecular Biology, Lund University, Sweden.
authors.forename: Alun C
authors.initials: AC
authors.lastname: Kirby
authors.forename: Malin
authors.initials: M
authors.lastname: Sundquist
authors.forename: Mary Jo
authors.initials: MJ
authors.lastname: Wick
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D007114:Immunization; D007156:Immunologic Memory; D051379:Mice; D008810:Mice, Inbred C57BL; D009928:Organ Specificity; D012481:Salmonella Infections, Animal / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D012486:Salmonella typhimurium / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D012703:Serotyping; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D019444:Vaccines, DNA