Age dependent increase in early resistance of mice to Mycobacterium tuberculosis is associated with an increase in CD8 T cells that are capable of antigen independent IFN-gamma production.
The lungs of naïve 18-month-old mice contain an abundant resident population of CD8 T cells that express typical markers of memory, express elevated levels of Th1 cytokine receptors on their surface, and are capable of non-specific IFN-gamma production in response to a Th1 cytokine cocktail. In this study we characterize this population of CD8 T cells in the lungs and spleens of mice with increasing age. In general, the proportion of CD8 T cells expressing markers of memory and Th1 cytokine receptors increased with age. The enhanced ability of CD8 T cells to produce IFN-gamma in an antigen independent manner followed this pattern as well, beginning to increase between 6 and 12 months of age. Interestingly, the phenotypic and functional age-related changes in CD8 T cells were also associated with a progressive age-related increase in early resistance to Mycobacterium tuberculosis. Taken together, these data suggest that as mice age a population of memory CD8 T cells, that are capable of contributing to innate immune responses to M. tuberculosis, gradually emerges and could be relevant for developing strategies to enhance immunity in the elderly.
Vesosky
Bridget
B
Center for Microbial Interface Biology, Division of Infectious Diseases, Department of Internal Medicine, The Ohio State University Columbus, OH 43210, USA. bridget.vesosky@osumc.edu
Flaherty
David K
DK
Rottinghaus
Erin K
EK
Beamer
Gillian L
GL
Turner
Joanne
J
D000375:Aging / Q000276:immunology*; D000818:Animals; D000941:Antigens / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D005260:Female; D007113:Immunity, Innate / Q000276:immunology; D007156:Immunologic Memory / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology*; D008168:Lung / Q000166:cytology / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009169:Mycobacterium tuberculosis / Q000276:immunology; D017471:Receptors, Interferon / Q000276:immunology; D018123:Receptors, Interleukin / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D014376:Tuberculosis / Q000276:immunology*
D000941:Antigens; D017471:Receptors, Interferon; D018123:Receptors, Interleukin; D007371:Interferon-gamma