The effect of mifepristone on the peripheral blood natural killer cell's cytotoxicity and expression of CD94/NKG2A and NKG2D during the implantation phase

ObjectiveTo investigate the effect of mifepristone on peripheral blood natural killer cell's (pbNK) cytotoxicity and the expression of the inhibitory receptor CD94/NKG2A and the activated receptor NKG2D on pbNK cells.DesignIn vitro study.SettingUniversity hospital and research laboratory.Patient(s)Twenty healthy nonpregnant women.Intervention(s)Detected the cytolytic activity of pbNK to K562 target cells; measured the expression of CD94/NKG2A and NKG2D on pbNK.Main Outcome Measure(s)Cytotoxicity of pbNK was detected by Methyl thiazolyl tetrazolium. The expression of CD94/NKG2A and NKG2D receptor on pbNK cells were detected by flow cytometry.Result(s)The NK cell cytotoxicity and the expression of inhibitory receptor CD94/NKG2A during the proliferative phase (81.71 ± 11.5, 86.6 ± 9.0) was significantly higher than the secretory phase (60.16 ± 19.2, 60.15 ± 31.0). The NK cells cytotoxicity, after being treated with mifepristone and the expression of inhibitory receptor CD94/NKG2A on pbNK cells treated with 200 nmol/L mifepristone, were significantly increased. Mifepristone had no effect on the expression of activating receptor NKG2D.Conclusion(s)These data suggest that Mifepristone maybe exert its anti-implantation function by increasing NK cytotoxicity. The increasing NK cytotoxicity of mifepristone is not related to CD94/NKG2A and NKG2D. In the secretory phase down-regulated CD94/NKG2A, NKG2D, and NK cytotoxicity may benefit with embryo implantation.