Role of CD8 T cell subsets in the pathogenesis of multiple sclerosis

► An independent association exists between the MHC class I alleles and MS. ► Oligoclonal expansion of CD8 T cells occurs within MS lesions and in the CSF. ► In transgenic models, mice developed a CD8 T cell-driven EAE. ► IL-17-producing CD8 T cells (Tc17) are present in active MS lesions. ► Suppressive activity of CD8 Treg correlates with clinical remission of MS.