Disclosed is a method for treating relapsing-remitting multiple sclerosis in a patient by administering to the patient autologous, ex vivo-expanded CD4+CD25+Foxp3+CD127low T reg cells when the patient is in remission. Also disclosed is a method of inhibiting the activity of autoimmune, autologous cytotoxic T and B cells in a patient suffering from relapsing-remitting multiple sclerosis, comprising administering a therapeutically effective amount of autologous CD4+CD25+Foxp3+CD127low T reg cells to the patient.