Influenza A virus specific T cell immunity in humans during aging

Virology. 2002 Jul 20;299(1):100-8. doi: 10.1006/viro.2002.1491.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aging / immunology*
  • CD8-Positive T-Lymphocytes / immunology
  • Cohort Studies
  • Female
  • Humans
  • Influenza A virus / immunology*
  • Interferon-gamma / analysis
  • Interleukin-4 / analysis
  • Ionomycin / pharmacology
  • Leukocytes, Mononuclear
  • Lymphocyte Activation / drug effects
  • Lymphocyte Count
  • Male
  • Middle Aged
  • T-Lymphocytes / immunology*
  • T-Lymphocytes, Cytotoxic / immunology
  • Tetradecanoylphorbol Acetate / pharmacology


  • Interleukin-4
  • Ionomycin
  • Interferon-gamma
  • Tetradecanoylphorbol Acetate