A team of researchers from the University of Virginia have found that the brain is directly connected to the immune system via vessels previously believed not to exist.

It is an important discovery in the realm of disease treatment. The immune system is supposed to protect the body, and the new study suggests that this could aid in finding new treatment for various neurological diseases like Alzheimer’s, autism and multiple sclerosis.

Jonathan Kipnis, a professor in the University of Virginia (UVa), Department of Neurosciences and the director of UVa’s Center for Brain Immunology and Glia and the lead author of the study said, “Instead of asking, ‘How do we study the immune response of the brain?’ ‘Why do multiple sclerosis patients have the immune attacks?’ now we can approach this mechanistically. Because the brain is like every other tissue connected to the peripheral immune system through meningeal lymphatic vessels.”

Thanks to the work of the postdoctoral fellow in Prof. Kipni’s lab, Antoine Louveau, who have developed a new method to count membranes covering the brains of a mouse on a single side, by which this unknown lymphatic vessel came to light.

Louveau said, “It was fairly easy, actually, there was one trick: We fixed the meninges within the skullcap, so that the tissue is secured in its physiological condition, and then we dissected it. If we had done it the other way around, it wouldn’t have worked.”

Kipnis said, “We believe that for every neurological disease that has an immune component to it, these vessels may play a major role. Hard to imagine that these vessels would not be involved in a [neurological] disease with an immune component.”

Kipnis added, “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.”

University of Southampton associate professor of cerebrovascular aging, Roxan Carare said, “The connections described are between the coverings of the brain and the immune system, rather than the brain itself and the immune system. The methodology is very impressive, but the findings need to be interpreted with caution in the context of diseases affecting the brain tissue itself.”

The findings of the study are published in the journal Nature.