Aging and antimicrobial immunity. Lowered efficiency of protective T cells as a contributing factor for the decreased resistance of senescent mice to listeriosis.
Experimental murine listeriosis was used as a model to investigate the immunological basis for the age-associated decline in antimicrobial immunity. The reduced capacity of protective T cells from Listeria-immune senescent mice to adoptively immunize normal syngeneic recipients could not be attributed to inhibition of their activity by suppressor cells. Radiolabeled enriched splenic T cells from Listeria-immune young or senescent donors exhibited an identical distribution pattern after an intravenous infusion into young recipients. Moreover, cells from Listeria-immune young donors showed markedly greater protective capacity than cells from senescent immune donors whether the cells were transferred to young or senescent recipients. Dose-response analysis of protective T cells revealed that in response to immunizing infection (a) senescent mice generated 10-fold fewer protective T cells, and (b) protective T cells from senescent mice were 100-fold less efficient than cells from young mice.
D000375:Aging; D000818:Animals; D002465:Cell Movement; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D007111:Immunity, Cellular; D007113:Immunity, Innate; D007116:Immunization, Passive; D008088:Listeriosis / Q000276:immunology*; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism