They discover a relationship between the brain and the immune system
This discovery has profound implications for neurological diseases from autism to Alzheimer’s disease to multiple sclerosis.
This is an impressive discovery that jettisoned decades of textbook teaching. Researchers at the University of Virginia School of Medicine (UVA) have determined that the brain is directly connected to the immune system by vessels that previously did not exist.
That these vessels escaped by the time the lymphatic system was very thoroughly mapped throughout the body is truly surprising, but the true significance of the discovery lies in the effects it could have on the study and treatment of neurological diseases ranging from autism, to Alzheimer’s disease and multiple sclerosis.
“Instead of asking, ‘How do we study the brain’s immune response? ‘Why do multiple sclerosis patients have immune attacks? now we can get closer to this mechanic. Because the brain is like any other tissue connected to the peripheral immune system through the meningeal lymphatic vessels, “said Jonathan Kipnis, PhD, professor in the Department of Neurosciences at UVA and director of the UVA Center for Brain Immunology. . “It completely changes the way we perceive neuro-immune interaction. We always perceived ourselves before as something esoteric that cannot be studied. But now we can ask mechanistic questions. ”
“We believe that for every neurological disease that has an immune component to it, these vessels can play an important role,” Kipnis said. “It is difficult to imagine that these vessels would not be involved in a (neurological) disease with an immune component.”
They’re going to have to change the textbooks
Kevin Lee, PhD, chair of the Department of Neurosciences at UVA, described his reaction to the discovery in Kipnis’s lab: “The first time these men showed me the basic result, I only said one sentence: ‘They are going to have to change the textbooks.’ There has never been a lymphatic system for the central nervous system, and it was very clear that the first singular observation – and many studies have been done since then to reinforce the finding – will fundamentally change the way of looking at the relationship of the central nervous system to the system. immune “.
Even Kipnis was skeptical at first. “I really did not believe that there were structures in the body that we are not aware of. I thought the body was mapped in its entirety, ”he said. “I thought these discoveries ended somewhere around the middle of the last century. But apparently not. ”
Very well hidden
The discovery was made possible by the work of Antoine Louveau, PhD, a postdoctoral fellow in the Kipnis lab. The vessels were detected after Louveau developed a method to mount a mouse meninges – the membranes that line the brain – on a single slide so that they could be examined as a whole. “It was pretty easy, actually,” he said.
After noticing the vessel patterns in the distribution of immune cells on his slides, he tried the lymphatic vessels and there they were. The impossible existed. Soft-spoken Louveau recalled the moment: “Jony [Kipnis] called me to go to the microscope and said, ‘I think we have something.’”
As for how the brain’s lymphatic vessels managed to escape from view all this time, Kipnis described them as “very well hidden” noting that they follow a major blood vessel down into the sinuses, an area that is difficult to remove. in picture. “It’s so close to the blood vessel, you miss it,” he said. “If you don’t know what you’re looking for, it’s out of your hands to see it.”
“Live images of these vessels were crucial in demonstrating their function, and it would not be possible without the collaboration of Tajie Harris,” Kipnis noted. Harris, PhD, is an assistant professor of neurology and a member of the BIG center. Kipnis also saluted the “phenomenal” surgical skills of Igor Smirnov, a research associate at the Kipnis lab whose work was critical to the study’s imaging success.
Alzheimer’s, autism, multiple sclerosis and more
The unexpected presence of lymphatic vessels raises an enormous number of questions that now need answers, both about the functioning of the brain and the diseases that affect it. For example, let’s take Alzheimer’s disease. “In Alzheimer’s disease, there are accumulations of large chunks of protein in the brain,” Kipnis said. “We think they can accumulate in the brain because they are not being effectively eliminated by these vessels.”
She noted that vessels look different with age, so the role they play in aging is another avenue to explore. And there are an enormous variety of other neurological diseases, from autism to multiple sclerosis, that must be reconsidered in light of the presence of something that science insisted did not exist.