Regulation of the Immune System by Sex Steroids*

IN THE PAST 10 years there has been a significant increase in studies relating to the function of the immune system. The recent popularity of research in this area is due in part to the awareness by the medical and scientific community of the importance of immune function in the maintenance of a disease-free homeostasis, to technological advances in the field of immunological research, and to the increased availability of funds for investigation in this area. From the rapidly expanding literature in this field it has become increasingly apparent that the immune system interacts with most, if not all, of the body systems. One of the most intriguing of these interrelationships is that which occurs between the immune and reproductive systems and involves interactions of pituitary hormones, gonadal steroid hormones and thymic hormones. Because of the complexity of this area the present review will concentrate on only one aspect of the interaction between the two systems, namely the effects of gonadal steroids on immune function.