University of California - San Francisco Feb 5 2026 Researchers at UC San Francisco have uncovered a new clue to how Epstein-Barr virus (EBV) could contribute to multiple sclerosis (MS), a chronic autoimmune disease that affects nearly one million Americans.  The study, published Feb. 5 in  Nature Immunology,  found that certain types of CD8+ "killer" T cells - immune cells that destroy damaged or infected cells - are more abundant in people with MS. Some of these killer T cells target EBV,