The Role of Cytokines in Immune Neuroendocrine Interactions

Abstract

In order to consider the interaction of immune and neuroendocrine systems, the following facts should be taken into account, (a) The immune system is capable of processing and responding to an enormous amount of information. Indeed, the immune system is surpassed only by the central nervous system (CNS) in terms of complexity, (b) The immune system participates in both physiological and pathological processes, and (c) both the immune and neuroendocrine systems are constantly in operation. Several soluble mediators released by the immune system have already been identified as messengers carrying afferent signals towards the CNS and there is little doubt that additional messengers will be found. Lymphokines, monokines, certain complement split products, immunoglobulins, histamine, serotonin, mediators of inflammation, thymic hormones, etc. are possible candidates for immune-CNS communication. Thus, it is possible that these messengers would carry information to the CNS about the type of immune response in operation, whereas the site of the response could be signaled through the local stimulation of nerve fibers by immune cell products released in their vicinity. The existence of afferent pathways from the immune system to the CNS implies, as we have previously suggested, that the immune system is a receptor-sensory organ.