Different IL-8 production by T and NK lymphocytes in elderly subjects

A gradual decline in the functional activity of the immune system is described with advancing age. The adaptive immune system seems the most severely affected, but some age-associated modifications also occurs in NK cells. Several studies investigated the age related changes of cytokine production, while little is known about chemokines, whose importance in regulating immune-response becomes even more evident. In this study we investigated whether the ability of T lymphocytes and NK cells to produce IL-8, either spontaneously or after activation, respectively with anti-CD3 monoclonal antibody or interleukin 2 (IL-2) was affected by age. We demonstrated that: (a) T lymphocytes and NK cells spontaneously produced detectable amounts of IL-8; (b) anti-CD3 stimulation of T lymphocytes significantly increased IL-8 production and the increment was more evident in the nonagenarian subjects; (c) similarly, IL-2 stimulation of NK cells rose the production of IL-8 but the amount produced by the old was lower than the one produced by the young group. Because of the co-stimulatory role of chemokines on NK responses and given the demonstrated importance of NK cells in defence against viral infections, the decreased production of IL-8 can be involved in the defective functional activity of NK cells from old subjects.