Immune System Can Affect Human Personalities And Social Behavior

The human immune system has surprising effects on your social life. It has more to do with neurological system and related conditions like autism-spectrum disorders and schizophrenia than previously thought. Researchers from the University of Virginia and University of Massachusetts Medical School developed and employed a novel systems-biology approach to study the complex dialogue between immune signalling and brain function in health and disease. They set up an experiment to shed light on the immune system molecule called ‘interferon gamma’, an important cytokine secreted by T lymphocytes in promoting social brain functions. Researchers found that in various organisms including rodents, fish and flies, and humans interferon gamma molecule is activated in social contexts. It is produced by the body when it's been exposed to pathogens and it then helps to trigger the proper, protective immune response. These studies uncovered a hidden connection between T-cell mediated immune signalling and social brain function.

Scientists conducted the immune system experiments in mice. They blocked the interferon gamma molecule through genetic engineering. When the immune system molecule was blocked, they became immunocompromised and the brains of the mice became ‘hyperactive’. They no longer displayed interest in socialization with their cage mates, something that mice are usually prone to do. A reduced interest in socializing might actually be a way of protecting an organism from infections that it can no longer fight off very well. It was concluded that manipulation of the immune system had a direct effect on behavior. When scientists discontinued the blockage of the immune system molecule, allowing it to once again operate freely in the brain, the mice calmed down and returned to their normal, social behavior. This shows that that the immune system – personality connection does exist. Researchers have postulated that the connection may actually be an evolutionary mechanism built in to help a species survive. The linkage exists, encouraging social creatures to interact and yet boosting our immune systems at the same time to protect both the individual and the group.

“Our findings contribute to a deeper understanding of social dysfunction in neurological disorders, such as autism and schizophrenia, and may open new avenues for therapeutic approaches,” said Vladimir Litvak, assistant professor at University of Massachusetts Medical School (UMMS).

One of the study’s authors, Johathan Kipnis, chair of the University of Virginia’s Department of Neuroscience said “The brain and the adaptive immune system were thought to be isolated from each other, and any immune activity in the brain was perceived as a sign of pathology.” He added, ”And now, not only are we showing that they are closely interacting, but some of our behaviour traits might have evolved because of our immune response to pathogens.”

The research published in the journal Nature states that it may be possible that people who suffer from various neurological and psychiatric disorders actually have malfunctioning immune system and that to fix their psychological problems they may need to fix the underlying medical problem first by restoring the immune system to full function. As of now, the immune system experiment has only been conducted on mice. This might mean for autism and other specific conditions further research is required.

Source-Medindia