New approach to treating multiple sclerosis

Researchers have identified an enzyme that triggers autoimmune responses from T cells in patients with multiple sclerosis (MS). These immune cells also reacted to a bacterial variant of the enzyme, supporting the idea that molecular “mimics” from members of the microbiome could be a driving factor in MS — an autoimmune condition that affects around 2.5 million people worldwide. MS arises when the immune system attacks the protective coating that sheathes neurons and transmits electrical impulses in the brain and spinal cord, resulting in a wide range of neurological issues. Although the disorder’s origins are masked by a complex array of genetic and environmental risk factors, scientists have theorised that many MS cases could be triggered by molecules from pathogens or bacterial microbiota. The researchers report preparing a T cell clone, previously isolated from MS brain lesions, and found the clone reacted against an enzyme named GDP-L-fucose synthase. The authors then examined CD4+ T cells from the cerebrospinal fluid (CSF) of 31 MS patients, and discovered nearly 40% of the individuals also displayed reactivity to the enzyme. The findings appear in Science Translational Medicine .