FIELD : biotechnology. SUBSTANCE : invention relates to the field of biotechnology, specifically to an antigen-MHC-nanoparticle complex, where the antigen is associated with multiple sclerosis antigen, and can be used in medicine. Antigen-MHC-nanoparticle complex can be used in the method expanding populations of anti-inflammatory autoreactive T-cells in people with multiple sclerosis, including the administration to the person of an effective amount of the antigen-MHC-nanoparticle complex. EFFECT : methods and compositions are disclosed for the treatment of multiple sclerosis and related diseases. 12 cl, 21 dwg, 3 tbl, 5 ex