This humanized MS model shows advantages over EAE, particularly spontaneous hCD8 T-cell lesions in the brain and spinal cord, mixed hCD8/hCD4 T-cell lesions in EAE-immunized mice, and more severe lesions in mice engrafted with PBMC from MS donors carrying the DRB1*15 MS susceptibility allele compared to DRB1*15-positive healthy and DRB1*13-positive MS donors. This evidence concerns the gene HLA-DRB1 and myeloid sarcoma.