Leukocytes in ovarian function

It has become apparent that in the ovary, the immune system contributes to the regulation of gonadal function. Leukocytes present within the ovary may constitute potential in-situ modulators of ovarian function that act through local secretion of regulatory soluble factors. These factors include numerous cytokines that largely originate by the action of immune cells within the ovary. Actual rupture of the follicle during ovulation may be dependent on tissue remodelling that is characteristic of an acute inflammatory reaction and includes mobilization of thecal fibroblasts, increased leukocyte migration, release of various mediators and loosening of connective tissue elements in the follicle wall. Both corpus luteum formation and luteal regression also involve progressive infiltration of lymphocytes and macrophages, release of chemokines and cytokines, and communication through cell adhesion molecules. In this review, we examine the evidence for the leukocytes and their products in regulation of ovarian function and relate the potential significance of these cells and substances to some ovarian disorders.