GNbAC1, a humanized monoclonal antibody against the envelope protein of multiple sclerosis-associated endogenous retrovirus: a first-in-humans randomized clinical study.

Background: Human endogenous retrovirus (HERV) genes represent about 8% of the human genome. A member of the HERV family W, the Multiple Sclerosis-Associated Retrovirus (MSRV) gene, encodes an envelope protein (Env), which can activate a proinflammatory and autoimmune cascade through its interaction with Toll-like receptor 4. Due to its proinflammatory property and an inhibitory effect on oligodendrocyte precursor cell differentiation, the MSRV-Env protein could play a crucial role in the pathogeny of multiple sclerosis.