Immunohistochemical Evidence for the Presence Of Tumor Necrosis Factor-α in the Infant and Adult Human Ovary

Abstract

The cytologic localization and cellular levels of tumor necrosis factor-α (TNFα) in the human ovary during follicular growth and regression were examined by the avidin/biotin immunoperoxidase method with a specific antibody to human recombinant TNFα. In the infant ovary, TNFα immunostaining was present only in the oocyte within the primordial follicles. TNFα immunostaining was also present within the oocyte in primordial follicles of the adult ovary. Positive immunostaining for TNFα in granulosa cells became apparent in preantral follicles, while that in theca interna cells began to appear at the antral follicle stage. The staining intensity of the oocyte increased as the oocyte reached the preovulatory stage. The intensity of immunostaining for TNFα in the granulosa and thecal cells increased as the follicle became larger and matured. In corpora lutea, the immunostaining for TNFα persisted in the granulosa lutein and theca lutein cells and intensified in the mid luteal phase. In the regressing corpora lutea, TNFct immunostaining in the luteal cells decreased as the regression advanced. Regressed corpora lutea with a central core of scar tissue were bordered by macrophage-like cells which exhibited intense immunostaining for TNFα. In the cortex region, the corpus albicans was negative for TNFα immunostaining, whereas macrophage-like cells peripheral to the corpus albicans exhibited intense immunostaining for TNFα. In the medullary region, the corpus albicans and surrounding stromal cells were totally negative for TNFα. By contrast, in the early atretic stage, the degenerating oocyte showed weak immunostaining for TNFα, while the granulosa and theca interna cells showed moderate immunostaining for TNFα. In the late atretic stage, the immunostaining for TNFα in the scattered granulosa cells became negligible, whereas the theca interna cells showed intense immunostaining for TNFα. The results obtained indicate that the oocyte is the primary intrafollicular site of TNFα localization within the ovary and that TNFα may participate in regulating follicular growth, regression and aresia.