Cytokine production in response to stimulation with tetanus toxoid, Mycobacterium tuberculosis and influenza antigens in peripheral blood mononuclear cells and T cell lines from healthy elderlies

Little is known about the type 1/type 2 T cell dichotomy in old age. Peripheral blood mononuclear cells (PBMC) and T cell lines from old and young healthy individuals were therefore analyzed for their production of interferon gamma (IFN-gamma) and interleukin 4 (IL-4). Tetanus toroid (TT), purified protein derivative of Mycobacterium tuberculosis, inactivated influenza virus and OKT-3 were used as stimuli. RT-PCR and ELISA determinations were performed. When stimulated with TT, PBMC from young and old individuals expressed IL-4, but produced little IFN-gamma. All other stimuli induced a pronounced IFN-gamma production, while little or no IL-4 was expressed. T cell lines, regardless of their specificity or the donor age, produced IFN-gamma and IL-4. The quantities of cytokines produced did not significantly differ between the age groups. The capacity of the immune system to trigger type 1 and type 2 T cell responses is thus well preserved in old age.