Prolactin response of NK cells, but not of LAK cells, is deficient in patients with carcinoma of oral cavity and during aging

The regulatory role of prolactin (Prl) on peripheral blood natural killer (NK) and lymphokine-activated killer (LAK) tell activities was studied in young (mean age, 40 years) and elderly (mean age, 68 years) healthy men and patients with carcinoma of the oral cavity (oral cancer). The peripheral blood NK cells, but not the LAK cells, were found to be depressed in oral cancer patients compared with age-matched healthy men. However, age-associated deficiency in both NK and LAK cell activity was observed in healthy men and cancer patients. Prl produced dose-dependent inhibition (1, 10, 100 or 250 ng/ml) or stimulation (25-50 ng/ml) of resting NK cells in young groups of healthy men and cancer patients. In elderly groups less or no response of the NK cells to low doses of Prl (1-10 ng/ml) was evident. The NK cells of young and elderly healthy men were stimulated by human recombinant Interleukin-2 (rlL-2) (100 U/ml), and Prl (1-250 ng/ml) inhibited these cells. In oral cancer patients an altered response to low doses of Prl (1-50 ng/ml) was observed in IL-2-stimulated NK cells, which also revealed malignancy-associated loss of IL-2 response. In contrast, there was no malignancy or age-associated change in Prl response of the LAK cells. Treatment of peripheral blood lymphocytes of both healthy men and oral cancer patients for 5 days with Prl (50 ng/ml) in the presence of low concentration of serum generated LAK cells. (C) 1996 Wiley-Liss, Inc.