There’s information emerging on how the common Epstein-Barr virus (EBV) might be crucial to triggering multiple sclerosis (MS).

The virus, which also causes “mono” (mononucleosis) and other illnesses, has gained prominence in recent years as a potential cause of MS. Over 95% of people are thought to carry EBV, although for most people it remains dormant.

Now, a team of Texan researchers report that certain immune cells targeted to EBV infection are found in high numbers in people newly diagnosed with MS.

The immune system cells are called T-cells, and they appear to be targeting lymphoblastoid cell lines (LCLs) infected with Epstein-Barr virus.

“This work demonstrates that T-cells specific for LCL are present in the cerebrospinal fluid at the earliest stages of [MS] disease,” said study senior author Dr. J. William Lindsey.

“This strongly suggests that these T-cells are either causing the disease or contributing to it in some way,” said Lindsey, a professor of neurology at McGovern Medical School, UTHealth Houston.

“We have experiments in progress to define what these cells may be doing,” he added in a UTHealth news release.

The study was published Jan. 8 in the Proceedings of the National Academy of Sciences.

EBV is a form of herpes virus that can be spread by bodily fluids, especially saliva. It’s been strongly linked in recent years to MS, a chronic, debilitating illness of the central nervous system affecting millions.

Just how EBV might help trigger MS has remained a mystery. In the new study, Lindsey’s team obtained samples of blood and cerebrospinal fluid from eight people midway through being diagnosed with MS.

They looked specifically at immune system T-cells within the cerebrospinal fluid samples, testing them to determine what pathogen or cell they might be sensitized to.

The answer: lymphoblastoid cell lines infected by EBV.

“This pattern was very different from what we observed in other neurologic diseases, suggesting it is unique to multiple sclerosis,” said study lead author Assaf Gottlieb. He is an assistant professor with the Center for Precision Health, part of the McWilliams School of Biomedical Informatics at UTHealth Houston.

Overall, 13% of the T-cells in the cerebrospinal fluid of folks newly diagnosed with MS were sensitized to EBV-infected cells. That suggests a clear link between the activity of these T-cells and MS, the research team concluded.

T-cells sensitized for three other common infections were not present at above-normal levels in the fluid samples, the Texas group noted.

More information

Find out more about the EBV-MS link at the Multiple Sclerosis Society.

SOURCE: University of Texas Health Science Center at Houston, news release, Jan. 8, 2024