Autoreactivity to myelin antigens: myelin/oligodendrocyte glycoprotein is a prevalent autoantigen

Autoreactive T cells specific for myelin antigens are thought to play a rol e in the pathogenesis of multiple sclerosis (MS). We compared T cell prolif erative responses in peripheral blood following challenge in vitro with mye lin/oligodendrocyte glycoprotein (recombinant protein, rMOG), myelin basic protein (MBP) and proteolipid apoprotein (PLP) in 50 patients with MS and 4 0 healthy controls. T cell reactivity against rMOG (defined by a specific s timulation index of 2.5 or greater) was present in 13 (26%) MS patients and 12 (30%) healthy controls and was MHC-restricted, as anti-MWC class LI ant ibodies abolished all proliferative responses. By contrast, reactivity agai nst PLP was present in only one(2%)) MS patient and six (15%) controls, and no reactivity against MBP was found in any subject. Thus, by the criteria of the present study, an increased reactivity of circulating T cells to MOG is present to a similar degree in healthy individuals and in patients with MS. This finding raises the possibility that additional factors contribute to the pathogenicity of these autoreactive T cell populations in demyelina ting disorders of the central nervous system. (C) 1999 Elsevier Science B.V . All rights reserved.