The relationship between the immune and endocrine systems

Increasing evidence links the immune and endocrine systems. Cytokines produced by activated immune and immune accessory cells can affect, positively or negatively, the secretion of hormones from the hypothalamic-pituitary-adrenal or hypothalamic-pituitary-ovarian axes. On the other hand, adrenal and ovarian hormones affect the secretion of cytokines by cells of the immune system. The interaction also occurs at a local level in paracrine or autocrine fashion. Cytokines produced by resident ovarian macrophages or ovarian cells can affect the follicle and the corpus luteum and, consequently, ovarian steroidogenesis at both phases of the menstrual cycle. Conversely, the ovarian steroids influence, positively or negatively, the secretion of cytokines from both the resident macrophages and local endocrine cells.