[Sex steroids and immunity: the role of estrogens on dendritic cells]

It is well known that 17beta-estradiol have diverse effects on the development of sexual traits, fertility and survival of neurons. On top of these effects, its participation as an important modulator of several immune functions has been described. For instance, estradiol participation has been invoked in relation to the immune sexual dimorphism, and, on sex associated incidence of several autoimmune diseases. Furthermore, its role during the resistance or susceptibility to many diverse infections (such as viral, bacterial and parasitic) has also been demonstrated. Dendritic cells (DCs) have a central role in the activation of the adaptative immune response, and in the maintenance of tolerance. In the last few years, the study of the effects of 17beta-estradiol on DCs has shown that this hormone regulates their differentiation and function, in vitro as well as in vivo. Depending on the context, 17beta-estradiol is able to exert benefic or deletorious effects. In the present communication, we summarize the described effects of estradiol on DCs, comparing the information obtained from studies in vitro versus the information from in vivo experiments.