PSYCHOBIOLOGICAL FACTORS RELATED TO HUMAN NATURAL-KILLER-CELL ACTIVITY AND HORMONAL MODULATION OF NK CELLS-INVITRO

The present report investigated whether percentages of circulating nat ural killer (NK) cells and NK cell activity (NKCA) are associated with psychological variables. Subjects (n=95) were selected, based on a co mbination of low or high scores on questionnaires on daily hassles and self-reported symptoms, to create four extreme groups. NK cell percen tages were different between two of the four groups, only when the ana lysis was not controlled for gender, life style and endocrine paramete rs. No evidence was found for a relationship between group membership and NKCA. NKCA, however, was found to differ between men and women and to be associated with percentages of NK cells and intracellular level s of cAMP. Furthermore, the hypothesis was tested, that hormone-induce d changes in NKCA in vitro are dependent on the individual's current s tress profile. To investigate this issue, NKCA was measured after cell s had been incubated with hydrocortisone (10(-6) or 10(-7) M) or the b eta-adrenergic agonist isoprenaline (10(-5) or 10(-7) M) in vitro. Cha nges in NKCA were found to be related to plasma adrenaline levels, but no evidence was found for involvement of psychological variables. It is concluded that, in the current setting, there is no association bet ween the combination of scores on the two psychological questionnaires , and NKCA or hormone-induced changes therein.