Effect of psychosocial stress on natural killer cell activity

Previous studies have indicated that the degree of stress controllability, rather than stress itself, may be a factor in immunosuppression. In the present study lymphocytes were obtained from individuals living in agricultural settlements in the Jerusalem area who are under the medical supervision of family-oriented primary health care clinics. Peripheral blood lymphocytes (PBL) obtained from married, adult males classified either as "copers" or as "non-copers" were tested for their natural killer (NK) activity and for the expression of the Leu 7 and Leu 11 NK-associated antigens. Differences were noted in the NK activity of PBL obtained from individuals belonging to various ethnic origins. Among Moroccan Jews the NK activity of non-copers was significantly lower than that of copers. In contrast, the proportion of PBL carrying antigenic markers of NK cells (Leu 7 and Leu 11) was higher among copers than among non-copers. Thus, psychosocial stress may lead in non-copers to decreased NK activity paralleled by an increase in the proportion of either immature pre-NK cells or possibly other immunoregulatory cells.