Aging, immunity and cancer.
Immunosenescence, the progressive decline in immune function that develops with age, results from cumulative alterations in critical B- and T-cell subpopulations. Decreases in circulating memory B cells and in germinal center formation are evident in the elderly, possibly due to diminished follicular dendritic-cell function. T-cell dysfunction is associated with reduced thymic generation of naïve T cells, virus-induced expansion of terminal effectors and increased levels of memory cells producing type I and II cytokines. The diversity of the T-cell receptor repertoire is diminished by the first two changes, and elevated type I cytokines might contribute to the pro-inflammatory cytokine milieu present in the elderly.
Hakim
Frances T
FT
Experimental Transplantation and Immunology Branch, National Cancer Institute, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892-1907, USA.
Flomerfelt
Francis A
FA
Boyiadzis
Michael
M
Gress
Ronald E
RE
D000368:Aged; D000375:Aging / Q000276:immunology*; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D004198:Disease Susceptibility; D006801:Humans; D007111:Immunity, Cellular; D007113:Immunity, Innate; D007156:Immunologic Memory; D051379:Mice; D018345:Mice, Knockout; D008954:Models, Biological; D009369:Neoplasms / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*