An exciting new discovery has turned the medical world upside down, and could have important implications for the treatment of multiple sclerosis (MS). It turns out that previously undiscovered vessels exist that connect the nervous system and immune system directly.
The study, titled “Structural and functional features of central nervous system lymphatic vessels“ was published on June 1st in the prestigious journal Nature.
In MS, the body launches a misdirected immune attack on the nervous system. This attack damages myelin, the wrapping that surrounds nerve cells and helps them transmit information. More direct connections between the immune and nervous systems may help explain how the disease develops.
Led by postdoctoral fellow Antoine Louveau, PhD, scientists at the University of Virginia studied the covering of the brain, called meninges, in mice. They discovered “functional lymphatic vessels” lining a region known as the dural sinuses, which are cerebrospinal fluid-filled compartments found under a type of meninges called the dura mater. They found that the structures were able to transport fluid and immune cells from the cerebrospinal fluid to “deep cervical lymph nodes,” providing a nervous system-immune system link. Cervical lymph nodes are immune system organs found in the neck.
Jonathan Kipnis, PhD, professor in the UVA Department of Neuroscience and director of UVA’s Center for Brain Immunology and Glia (BIG) reacted to the finding: “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. It changes entirely the way we perceive the neuro-immune interaction. We always perceived it before as something esoteric that can’t 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 may play a major role,” Kipnis further noted. “Hard to imagine that these vessels would not be involved in a [neurological] disease with an immune component.”
If this newly discovered system can be used for drug delivery, or further studied to gain understanding of how MS develops, it could mean great news for people suffering from MS in the future.
In the article the researchers note, “The discovery of the central nervous system lymphatic system may call for a reassessment of basic assumptions in neuroimmunology and sheds new light on the etiology [cause] of neuroinflammatory and neurodegenerative diseases associated with immune system dysfunction.”
The finding has prompted a revision of biological and medical textbooks to make room for the newly discovered system. Researchers hope that the discovery will spur on a wide range of research projects, including those associated with multiple sclerosis.