The endocrine function of the immune cells in the initiation of humoral immunity

The endocrine functions of different hormones are well documented. Recently, however, evidence of the immune function of several hormones has been accumulated. These findings raised the possibility that immune cells might secrete hormones and in turn self-regulate different immune functions. Indeed, immune cells have been found to secrete different peptide and protein hormones. Adrenocorticotropin hormone (ACTH) is the most studied and was found to be secreted by lymphocytes. In the present authors' laboratory, it was found that not only do lymphocytes secrete ACTH but also that circulating concentrations of corticosterone increased following antigen challenge. It was also observed that at the time of the increased corticosterone, there was a redistribution of different lymphocyte subpopulations from the blood to spleen, the site of antigen presentation and antibody production. It was concluded that the endocrine function of lymphocytes might be important in the initiation of antibody production in chickens.