RECOMBINANT CYTOKINES AS AN APPROACH TO IMMUNE RECONSTITUTION IN AGING

Aging is characterized by a decreased humoral and cell-mediated immuni ty to a large variety of exogenous antigens and by an increased propen sity to autoantibody production, suggesting an age-related disregulati on of the immune system. The decline in immune responsiveness to exoge nous antigens has been attributed to thymus involution, consisting of a fall in the capacity to induce intrathymic T-cell growth and differe ntiation, and also to export mature T cells to the periphery. T-cell a ctivation and secretion of soluble factors have been reported to chang e with aging, but, as with cytokines, the results are conflicting. We investigated the production of IL-2 and IFN-gamma (Th1 type) and IL-4 (Th2 type) cytokines by mitogen-activated spleen cells from young, adu lt and old mice and their regulation by the addition of a recombinant cytokine (IL-1 beta, IL-2, IL-3, IL-4, IL-12, IFN-gamma) at varying co ncentrations. The results indicate that cytokine production can be enh anced only when it is deficient, suggesting the possible use of recomb inant cytokines as efficient immunomodulators in age-associated immune disorders. (C) 1997 Elsevier Science Ltd. All rights reserved.