Our body systems are like sections in an orchestra, "conducted" by the brain. But how exactly does the brain, which is part of the central nervous system, send its messages directly to the other systems? While nerve cells communicate through neurotransmitters, the immune system's T cells, for instance, do their talking through entirely different molecular messengers, the most important ones being cytokines.
Dr. Mia Levite of the Weizmann Institute's Immunology Department has discovered that there is indeed direct communication between the nervous and immune systems. In a study reported recently in the Proceedings of the National Academy of Sciences, she showed for the first time that neurotransmitters can "order" cytokine secretion from T cells.
This may help explain how immune system cells can be activated by the brain in the absence of any classical immunological trigger such as bacteria or viruses. By eavesdropping on this molecular dialogue, scientists may gain new insights into the way information sensed by the nerves can affect the immune system, calling upon it to adjust to a new situation, such as stress.
Levite's study may also account for rapid T cell activation by the nervous system, since neurotransmitters deliver their messages extremely quickly. Thus, our bodywide system of nerves may serve as the immune system's information superhighway, helping to coordinate the activity of its various isolated components.
Interestingly, Levite found that when T cells are activated by the nervous system, they can secrete types of cytokines that they are normally forbidden to release. This finding is very important for understanding, and possibly one day also treating, the disorders in which the delicate balance between different sets of cytokines is disrupted, such as numerous autoimmune diseases like multiple sclerosis and juvenile diabetes.
The Weizmann Institute of Science is a major center of scientific research and graduate study located in Rehovot, Israel.