UVa researchers expand on brain-immune connection discovery
CHARLOTTESVILLE, Va. (AP) — University of Virginia researchers are one step closer to understanding the immune system-brain connection that they discovered last year.
Immune cells normally found in the gut, lungs and skin also reside in the meninges, the membranes surrounding the brain and spinal cord, according to a new report from the university’s Kipnis Lab. Researchers believe that figuring out how to target and manipulate the cells could be key to treating various neurological disorders, such as Alzheimer’s disease, migraines and injuries to the brain and spinal cord.
“We’re really excited to find this other facet (of the brain-immune connection) and feel like taking more of a total approach to manipulating the cells might produce more results for treating migraines and other diseases,” said Jonathan Kipnis, director of the lab.
The Kipnis Lab achieved international attention last year when it published its discovery of lymphatic vessels in the brain, establishing a physical connection between the brain and the immune system that was previously unknown.
The latest discovery, of the cells known as type 2 innate lymphocytes, in the meninges caught the researchers off guard. These white blood cells protect against pathogens in the body but are also among the chief culprits behind allergies, asthma and certain types of autoimmune disorders. Most research on type 2 innate lymphocytes has focused on their role in these conditions.
Kipnis said he did the experiment that led to the discovery “on a whim” after reading about type 2 innate lymphocytes in another paper.
“This is a huge surprise to me,” he said.
Understanding what type 2 innate lymphocytes do in other parts of the body could provide insight to their role in neurological disorders. In the gut, the lymphocytes maintain a barrier against pathogens. The lymphocytes in the skin are important in wound healing. They are part of the body’s inflammatory response that protects people from infection.
The cells also trigger inflammatory responses in the brain, in response to injury, said Sachin Gadani, another researcher in the Kipnis Lab.
“This is the first line of defense,” Gadani said. “Here, we’re seeing the most (important) cells in the immune system are in the brain, ready to respond to an injury.”
This inflammation is beneficial during a brain injury, but the uncontrolled response also might be behind certain neurological disorders, such as Alzheimer’s. Learning how exactly the cells work — and their role in neurological disorders — could lead to breakthroughs in treatment, Kipnis said.
“We might be able to activate the inflammation in a controlled manner that actually works,” he said. “That’s a long-term goal of the lab.”
A recent study showing that Parkinson’s disease could be caused by bacteria in the gut is even more intriguing to the researchers at the Kipnis Lab. The study, published this month by a group of scientists from several California universities, found that among mice with genetic predisposition to developing Parkinson’s, only those with gut bacteria actually developed symptoms.
The scientists told the BBC television network that they believe the gut bacteria release chemicals that over-activate immune cells in the brain.
Researchers at UVa think the lymphocytes in the meninges act as a sort of middleman between the changes in the gut and the effects manifested in the brain. It’s speculation for now, Kipnis said, but if it’s true, then scientists could find a way to manipulate the process using drugs.
“By finding these physical links, we might be able to understand why things in our gut affect our brain,” Kipnis said. “And if we understand things in enough details, we might be able to manipulate it.”
Information from: The Daily Progress, http://www.dailyprogress.com