INTERLEUKIN-1-ALPHA AND INTERLEUKIN-1-BETA MODULATION OF LUTEINIZED HUMAN GRANULOSA-CELL ESTROGEN AND PROGESTERONE BIOSYNTHESIS

This study was designed to test the hypothesis that interleukin-1 alph a (IL-1 alpha) and beta directly affect progesterone, and oestradiol p roduction in cultures of purified human granulosa cells, Luteinized gr anulosa cells were obtained from women during in-vitro fertilization c ycles. Granulosa cells with and without associated white blood cells w ere cultured in the presence of IL-1 alpha and IL-1 beta (0.5-50 ng/ml ) for 48 h. Media were changed at 24 h intervals and assayed for proge sterone and oestradiol, In separate experiments, granulosa cell viabil ity was assessed with the tetrazolium salt reduction assay, haemocytom eter cell counts, and Trypan blue dye exclusion. Our results indicate that progesterone synthesis by basal and human chorionic gonadotrophin (HCG)-stimulated granulosa cells co-cultured with white blood cells w as inhibited by 5.0 ng/ml of IL-1 alpha and IL-1 beta at 48 h of cultu re, In the presence of white blood cells, granulosa cell oestradiol sy nthesis-was inhibited by IL-1 beta but not IL-1 alpha. Oestradiol was inhibited after both 24 and 48 h of culture and was maximal)y affected by 5.0 ng/ml Of IL-1 beta. In contrast, basal and HCG-stimulated oest radiol production by granulosa cells cultured free of white blood cell s was inhibited only by IL-1 alpha. IL-1 alpha at 5.0 ng/ml produced m aximal inhibition of basal oestradiol (57%) and HCG-stimulated oestrad iol (41%) production at 48 h of culture, Gonadal steroid inhibition by IL-1 alpha and IL-1 beta was not mediated through cytotoxic or antipr oliferative effects on granulosa cells, Specificity of the granulosa c ell response to IL-1 alpha and IL-1 beta was demonstrated by abrogatio n of steroid inhibition with anti-IL-1 alpha and IL-1 beta neutralizin g antibodies. In conclusion, IL-1 alpha directly inhibited the product ion of oestradiol by human ovarian granulosa cells. IL-1 alpha and IL- 1 beta also exerted indirect effects on steroid production via white b lood cells that are usually present in granulosa cell cultures if step s are not taken to remove them, These data support the hypothesis that cytokines play an important role in intra-ovarian regulation of stero id biosynthesis.