Lack of Antibody Production Following Immunization in Old Age: Association with CD8+CD28− T Cell Clonal Expansions and an Imbalance in the Production of Th1 and Th2 Cytokines

摘要: Although it is generally recognized that the function of immune system declines with age, nature underlying defects still poorly understood. We now demonstrate predominance CD8(+)CD28(-) T cell clonal expansions in elderly persons who fail to produce specific Abs following influenza vaccination. These clones express effector markers and are mostly CD45RA(+). When isolated put into culture, they unable proliferate, but IFN-gamma (but no IL-5) upon stimulation anti-CD3 or autoantigen. autoreactive CD8(+) type 1 cells seem trigger a Th1 polarization, as CD4(+) from without vivo Ab production Th1, only low amounts Th2 cytokines vitro PHA. Therefore, increased occurrence may be decisive for development deficiency elderly.