Immune cells in brain play significant role in schizophrenia: Study

Sydney: Researchers have identified that some people with schizophrenia have greater amounts of immune cells in their brains, a finding that could open the doors to new treatments and therapies.

Thousands of people worldwide live with schizophrenia — a severe mental disorder that affects a person’s ability to think, feel and behave clearly. No single cause of the condition has been identified yet.

The study, led by Professor Shannon Weickert at the University of New South Wales in Australia, challenged the assumption that immune cells were independent of the brain in psychiatric illness and “identified immune cells as a new player in the brain pathology of schizophrenia”.

Current schizophrenia research focuses on the status of three brain cells: the neurons; the glial cells, which support the neurons; and the endothelial cells, which coat the blood vessels.

However, Weickert and her team employed new molecular techniques and identified the presence of a fourth cell, the macrophage — a type of immune cell in the brain tissue of people with schizophrenia who show high levels of inflammation.

The discovery, detailed in the journal Molecular Psychiatry, shows that specific immune cells are in the brains of some people with schizophrenia in close enough proximity to the neurons to do damage.

“This opens whole new avenues for therapy, because it suggests that the pathology of schizophrenia could be within the immune cells and the immune cells could be contributing to the symptoms of schizophrenia,” Weickert said.

The study observed that in people with schizophrenia, the glial cells, one of the local residents, become inflamed and produce distress signals which change the status of the endothelial cells.

This may cause the endothelial cells to extend sticky tentacles so when the immune cells travel, some are captured.

“These cells may transmigrate across the blood brain barrier entering the brain in greater amounts in some people with schizophrenia compared to people without the disorder,” Weickert explained.

The study has the potential to transform global schizophrenia research and open new avenues for developing targeted immune cell therapies.