For the first time scientists have found that the brain is connected directly with the immune system in body and communicates via lymphatic vessels that was not known before to have existed, heralding a new chapter in science books altogether.
Researchers were taken aback by the findings. “I really did not believe there are structures in the body that we are not aware of. I thought the body was mapped,” said study author Jonathan Kipnis from the University of Virginia.
Kipnis and his team hit headlines in February after their discovery of a direct link between brain alerting the immune system in the body after spinal injuries by his gradaute student Sachin Gadani, an Indian-origin researcher.
Citing past knowledge, Kipnis, who is also director of UVA’s Center for Brain Immunology and Glia (BIG), says that these vessels were not supposed to have been there but the discovery will force them to remap the body’s nerous system.
“I thought the body was mapped and that these discoveries ended somewhere around the middle of the last century. But apparently they have not. We believe that for every neurological disease that has an immune component to it, these vessels may play a major role,” he noted.
Now that the central lymphatic nervous system has been found in the brain, soon researchers can find answers to Alzheimer’s, where there are accumulations of big protein chunks in the brain, not removed effeciently by these vessels. “In Alzheimer’s, there are accumulations of big protein chunks in the brain. We think they may be accumulating in the brain because they’re not being efficiently removed by these vessels.”
The study could unravel new treatment to Alzheimer’s and even cancer, says Kipnis. “The first time these guys showed me the basic result, I just said one sentence: ‘They’ll have to change the textbooks.’ There has never been a lymphatic system for the central nervous system, and it was very clear from that first singular observation.”
The current research came cose on the heels of their discovery last year of a protective form of immune response to spinal cord injury, a biological trigger that can provide clues to harness the body’s defenses to improve treatment for spine injuries, brain trauma, Alzheimer’s disease and other neuro-degenerative conditions.
Their past research idea came from Sachin Gadani, Indian-origin grduate student in UVA. He came out with the discovery that the trigger — the molecule interleukin-33 — is concentrated in what is known as “white matter” in the healthy brain and spinal cord.
It was released immediately after an injury and activates cells called glia, beginning the body’s protective response and promoting recovery faster.
“It’s the first thing that tells the immune system that something’s been damaged,” said Sachin Gadani, whose paper was published in the journal Neuron in February. “It’s how the immune system initially knows to respond.”
IL-33 may represent a language through which the central nervous system is constantly talking with the immune system – or, in other words, a molecular mind-body connection, explains Kipnis. Previous findings too have connected interleukin-33 to Alzheimer’s disease.
“There’s a huge link,” Gadani said. “Researchers have identified a strong connection between interleukin-33 and Alzheimer’s disease, and our work will pave the way for future studies on this topic.”
Eventually, the findings could lead to both improved treatments and new diagnostic tests for brain and spinal cord injury, Alzheimer’s and other conditions.