Researchers at UC San Francisco have uncovered evidence showing how the Epstein-Barr virus may trigger immune responses in multiple sclerosis patients. The study reveals elevated levels of virus-targeting immune cells in the nervous systems of those with the disease. These findings, published in Nature Immunology, suggest potential new treatment avenues by targeting the virus.
Multiple sclerosis (MS) is a chronic autoimmune disorder affecting nearly one million people in the United States, where the immune system attacks the myelin sheath protecting nerve fibers in the brain and spinal cord, leading to progressive neurological damage.
A new study from UC San Francisco provides fresh insights into the role of the Epstein-Barr virus (EBV) in MS. EBV, which infects about 95% of adults and is present in nearly all individuals who develop MS, has long been associated with the disease. The research, published on February 5 in Nature Immunology, focused on CD8+ "killer" T cells, which are less studied than CD4+ T cells but play a direct role in destroying infected cells.
The team analyzed blood and cerebrospinal fluid (CSF) samples from 13 people with MS or early signs of the disease, compared to five without MS. In healthy individuals, CD8+ T cells that recognize specific proteins appeared in similar concentrations in blood and CSF. However, in MS patients, these EBV-responsive cells were 10 to 100 times more abundant in the CSF than in the blood, indicating heightened immune activity within the central nervous system.
EBV was detected in the CSF of most participants, with some viral genes active. Notably, one EBV gene was active only in those with MS, suggesting it may drive the aberrant immune response.
"Looking at these understudied CD8+ T cells connects a lot of different dots and gives us a new window on how EBV is likely contributing to this disease," said senior author Joe Sabatino, MD, PhD, an assistant professor of Neurology at UCSF and member of the UCSF Weill Institute for Neurosciences.
The virus has also been linked to other autoimmune conditions like lupus, rheumatoid arthritis, and long COVID. Researchers are exploring treatments that target EBV directly.
"The big hope here is that if we can interfere with EBV, we can have a big effect, not just on MS but on other disorders, and improve the quality of life for many, many people," Sabatino added.
The study was funded by the National Institutes of Health and involved numerous UCSF collaborators.
