Endocrinology: the active partner in PNI research

For the past two decades, research appearing in the pages of Brain, Behavior, and Immunity (BBI), as well as other journals, has significantly deepened our understanding of the complexities of endocrine regulation of immunity in states of health and disease. This mini-review discusses contributions that endocrinology has made to the field of psycho-neuroimmunology (PNI), as well as discoveries that PNI researchers have made of the pervasive interactions between the endocrine and immune systems. We highlight the endocrine-immune interface, emphasizing similarities between the immune and endocrine systems as well as hormone/cytokine interactions. Differing endocrine-immune responses to acute and chronic psychosocial stress have been clarified during this time frame with the use of novel stress and endocrine sampling paradigms. Furthermore, investigations examining the role of cytokine involvement in acquired glucocorticoid resistance in illnesses like depression have expanded our understanding of the complexity of the endocrine-immune response to psychosocial stress. We have selected literature, with a focus on human studies, to illustrate these principals. We conclude with a discussion of the clinical relevance of endocrine-immune investigations and thoughts about the next decade of endocrine research in PNI.