Effects of Estrogen and Progesterone on Different Immune Cells Related to Multiple Sclerosis

Multiple Sclerosis (MS) is a chronic autoimmune disease of young adults with an unknown etiology, but cellular immune responses and inflammation has a pivotal role in this regard. The higher incidence of MS among women indicates the possible involvement of female sex hormones on the disease course. Progesterone and estrogen are the most important sexual hormones in women. They exert different immunomodulatory effects through both nuclear and membrane associated receptors present in different immune cells. The immunological effects include shifting the immune response towards Th2, stimulating Treg production, inhibiting pro-inflammatory cytokine production, prohibiting cell migration into Central Nervous System (CNS), suppressing proinflammatory immune cells, stabilizing the neuronal environment, and promoting neuronal survival, all of which might ameliorate the condition in women suffering from MS. Some clinical trials have reported a correlation between the use of Oral Contraceptives (OCs), which contain estrogen and progesterone, and MS among women. Some of these studies show a positive effect of OC usage on the onset and severity of the disease while others have found no significant impact. In this review, we collected articles published between 1995 and 2017 from PubMed Central and Google Scholar for evaluating effects of estrogen and progesterone on different immune cells related to MS.