Influenza A virus specific T cell immunity in humans during aging.
To study the decreasing responsiveness of the immune system during aging, influenza virus specific cellular immunity was investigated in a cohort of healthy blood donors between 18 and 70 years of age. The percentage of influenza A virus specific T cells was determined by flow cytometry and found not to change during aging. After stimulation with phorbol 12-myristate 13-acetate and ionomycin, an increase in the percentage of IFN-gamma and IL-4 producing CD8(+) T cells was observed during aging. In addition, the cytotoxic T lymphocyte (CTL) activity was investigated in two additional groups of five donors, 18-20 and 68-70 years of age. The lytic capacity of purified CD8(+) T cells, after in vitro stimulation of peripheral blood mononuclear cells with influenza A virus, seemed lower in 68- to 70-year-old donors than in 18- to 20-year-old donors. Therefore we conclude that the reduced CTL activity in the elderly is not the result of a lower frequency of virus-specific T cells, but more likely the result of impaired antigen-specific proliferation or lower lytic capacity of these cells.
Boon
A C M
AC
Erasmus University Rotterdam, Institute of Virology, Rotterdam, Netherlands.
Fringuelli
E
E
Graus
Y M F
YM
Fouchier
R A M
RA
Sintnicolaas
K
K
Iorio
A M
AM
Rimmelzwaan
G F
GF
Osterhaus
A D M E
AD
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D009980:Influenza A virus / Q000276:immunology*; D007371:Interferon-gamma / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis; D015759:Ionomycin / Q000494:pharmacology; D007963:Leukocytes, Mononuclear; D008213:Lymphocyte Activation / Q000187:drug effects; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015847:Interleukin-4; D015759:Ionomycin; D007371:Interferon-gamma; D013755:Tetradecanoylphorbol Acetate