[Relation and interactions between the immune and neuroendocrine systems]

For far too long, the immune system has been viewed in isolation from the rest of the body's organ system. But now it is clear that the immune system is an integral part of the organ and physiological systems of whole organism. Especially, the immune and endocrine systems share many ligands and receptors that result in constant and important bidirectional communication. A new and important function for the immune system is to serve as a sensory organ for noncognitive stimuli such as infectious agents and tumours. On the other hand the neuroendocrine system can perform important immunoregulatory activities. It also suggest that brain is not more an immunologically privileged site. Recent studies provide a new view of immunoreactivity to antigens from the nervous system and to immune and inflammatory responses in brain. These may be influenced both by the circulating cytokines derived from the immune system and/or those endogenously produced within the neuroendocrine system. There is a growing body of evidence that cytokines are an integral part of the central nervous system with an important neuromodulatory role in neural mechanisms regulating stress responses, hormonal changes and various kinds of behavior. The mutual informatory circuit inside of the immune, nervous and endocrine systems suggest that they all form the superinformation system with pivotal regulatory role in living organisms. Overall, the recognition of the immune system as our sixth sense may ultimately provide the new understanding of physiology required for successful diagnostic and therapeutic programs against disease and stress involving immune-neuroendocrine communication. (Tab. 5, Ref. 35.)