The importance of ovary-immune interactions in the context of age and disease

The ovary, a dynamic endocrine organ, plays a central role in female reproductive function through the secretion of hormones such as 17β-estradiol, progesterone, testosterone, and inhibin. Beyond its endocrine activity, the ovary serves as a critical site of immune modulation, with tissue-resident and circulating immune cells contributing to folliculogenesis, ovulation, implantation, and pregnancy. This review explores the reciprocal interactions between the ovarian and immune systems across health, disease, and aging. We highlight the diverse functions of ovarian immune cell types in maintaining reproductive homeostasis and their dysregulation in conditions such as polycystic ovary syndrome (PCOS), premature ovarian insufficiency (POI), ovarian hyperstimulation syndrome, and autoimmune diseases. Additionally, we discuss how ovarian removal or dysfunction influences systemic inflammation and increases susceptibility to cardiovascular and neurologic disorders. Together, these findings underscore the ovary's dual role as an endocrine and immune organ, highlighting its significance in female health and disease beyond reproduction.