In vitro treatment with interleukin-2 normalizes type-1 cytokine production by lymphocytes from elderly

The term immunosenescence is taken to mean the deterioration of immune func tion seen in elderly, which is manifested in increased susceptibility to in fectious diseases, neoplasias, and autoimmune diseases. It is only recently that we have begun to understand the cellular and molecular changes involv ed. Of special interest in this regard are observations of a decline in syn thesis of Type-1 cytokines which predisposes to diminished cell mediated im munity. We have evaluated the production of type 1 cytokines in old and you ng donors either in presence or in absence of recombinant interleukin-2 (rI L-2). Lymphocytes were stimulated with plastic bound anti-CD3 and after 48 h the supernatants were harvested and stored at -70 degrees C until assay. Type 1 cytokine, i.e. IL-12 and interferon-gamma (IFN-gamma) production by anti-CDS stimulated lymphocytes from old subjects was significantly reduced when compared to that from young ones. This impaired production was revers ed by adding rIL-2 in the culture medium. In previous studies on aged subje cts, we have been able to demonstrate that in vitro treatment with rIL-2 co mpletely restores proliferative responses and partially rescues the increas ed apoptosis of T cell cultures. Present and previous results suggest that rIL-2 completely restores Type 1 responses by overcoming the well known cos timulation deficit of aged lymphocytes.