Hormonal modulation of human natural killer cell activity in vitro

This study investigates the effect of steroid and polypeptide hormones on human NK cell activity in vitro. Solutions of hormones were incubated with normal peripheral blood cells in a 4 h cytotoxic assay against the NK-sensitive erythromyeloid cell line K562. The steroid hormones oestradiol, progesterone and testosterone did not exhibit a significant effect on K562 lysis at concentrations within the normal physiological range. HCG and LH, however, had a marked effect on NK activity, the latter at concentrations within the range observed in normal menstruating females.