INTERFERON-GAMMA INHIBITS LUTEINIZED HUMAN GRANULOSA-CELL STEROID-PRODUCTION IN-VITRO

OBJECTIVE: The purpose of this study was to determine whether interfer on gamma affects luteinized human granulosa cell progesterone, estrone , and estradiol production in the presence and absence of associated w hite blood cells by either cytotoxic or antiproliferative mechanisms. STUDY DESIGN: Luteinized granulosa cells were isolated by Percoll cent rifugation from women during in vitro fertilization cycles. Some cell suspensions were further treated with anti-CD45 magnetic immunobeads t o remove associated white blood cells. Granulosa cells with and withou t white blood cells were cultured in the presence of interferon gamma (0.5 to 50 ng/ml) for 48 hours. Medium was changed at 24-hour interval s, and spent medium was assayed for progesterone, estrone, and estradi ol. In separate experiments granulosa cell viability was assessed with the tetrazolium salt reduction assay. RESULTS: Interferon gamma signi ficantly inhibited granulosa cell progesterone production in both basa l and human chorionic gonadotropin-stimulated cells cocultured with wh ite blood cells in a concentration-dependent manner, whereas cells cul tured free of white blood cells demonstrated less inhibition. In the a bsence of interferon gamma a more profound increase in granulosa cell progesterone synthesis was found in human chorionic gonadotropin-stimu lated cultures without associated white blood cells. Interferon gamma inhibited granulosa cell estrone and estradiol production in basal cul tures containing white blood cells in both a time- and concentration-d ependent manner. Estrone production was not affected by interferon gam ma in human chorionic gonadotropin-stimulated granulosa cell cultures containing white blood cells, whereas estradiol secretion was decrease d at 48 hours with 50 ng/ml interferon gamma. Both estrone and estradi ol synthesis were inhibited by 50 ng/ml interferon gamma in granulosa cell cultures free of white blood cells. In cultures free of interfero n gamma, granulosa cell estrone and estradiol secretion was not affect ed by human chorionic gonadotropin stimulation compared with basal con trols regardless of the presence or absence of white blood cells. All concentrations of interferon gamma used had no effect on granulosa cel l viability at any time point tested. CONCLUSIONS: Our data suggest th at interferon gamma affects granulosa cell steroid production both ind ependently and in synergy with associated white blood cells and furthe r supports the hypothesis that interferon gamma may be an important in traovarian regulator of ovarian steroid production during the luteal p hase.