Brain Lymphatic Vessels May Serve as Potential Target for MS Treatment

New research has found that lymphatic vessels surrounding the brain may play a crucial role in the development and progression of multiple sclerosis (MS). The vessels may also play a key role in other neuro-inflammatory diseases and brain infections as well.

Researchers from the University of Virginia School of Medicine found that the vessels appear to carry previously unknown messages from the brain to the immune system that ultimately trigger the symptoms of MS.

By targeting the lymphatic vessels surrounding the brain, the researchers were able to impede the development of MS in a mouse model using a number of strategies to block or destroy the vessels, effectively decreasing the amount of destructive immune cells capable of causing paralysis.

“Meningeal lymphatic vessels are quite small compared to other lymphatics in the body, and we and others wondered if this might limit the amount and size of cargo they can pass through,” study author Jasmin Herz said in a press release about the findings. “During inflammation, they did not change in size or complexity much, but what was really exciting to discover [was that] they allowed whole immune cells to traffic through them, and we found molecular cues for that.”

These findings suggest that MS pathology could be triggered by a signal sent from the brain to the immune system. Therapies targeting these vessels could be beneficial; however, the researchers noted that many of the brain mechanisms underlying its connection to the immune system are still poorly understood. Further research could focus on identifying the specific signaling used by the brain to drive communication.

Additionally, removing the lymphatic vessels did not completely stop MS, indicating a more complex combination of factors contributing to the development of the disease. Although blocking the cells in mice seemed to be beneficial, the researchers also found that the vessels’ healthy function helps prevent Alzheimer disease and age-related cognitive decline.

“These findings on the role of brain-draining lymphatic vessels in MS, together with our recent work on their role in [Alzheimer] disease, demonstrate that the brain and the immune system are closely interacting,” lead study author Jonathan Kipnis, PhD, said in the press release.

According to Dr Kipnis, these lymphatic vessels could potentially serve as a valuable target for therapeutic intervention for neurological disorders.

The study was published in Nature Neuroscience.

References

Louveau A, Herz J, Alme MN, et al. CNS lymphatic drainage neuroinflammation are regulated by meningeal lymphatic vasculature. Nature Neuroscience. 2018. https://www.nature.com/articles/s41593-018-0227-9

UVA identifies brain’s lymphatic vessels as new avenue to treat multiple sclerosis [news release]. UVA’s website. https://newsroom.uvahealth.com/2018/09/17/uva-identifies-brains-lymphatic-vessels-as-new-avenue-to-treat-multiple-sclerosis/. Accessed September 17, 2018.