Myelin proteolipid protein-induced experimental allergic encephalomyelitis. Variations of disease expression in different strains of mice

Strains of mice with diverse genetic backgrounds were tested for susceptibility to experimental allergic encephalomyelitis (EAE) induced by myelin proteolipid protein. EAE was elicited in all strains of mice tested, but the clinical and histologic features varied. SJL (H-2s) mice had a high incidence of both clinical and histologic disease characterized by early onset of clinical signs. Inguinal lymph node T cells from diseased animals responded specifically [( 3H]thymidine incorporation) to proteolipid protein and not to myelin basic protein. In contrast, BALB/c (H-2d), DBA/1 (H-2q), C57BL/6 (H-2b), AKR (H-2k), CBA (H-2k), C3H (H-2k), B10.BR (H-2k), and C57BR (H-2k) mice showed a later onset of clinical signs and typically a lower disease incidence. However, the most marked variations in disease incidence occurred among BALB/c (H-2d) substrains in which the incidence of EAE ranged from eight of nine (BALB/cPt) to complete resistance (BALB/cWt and BALB/cORNL). Because these BALB/c substrains were initially derived from the same inbred genetic source and are serologically identical at H-2, these results suggest that expression of proteolipid protein-induced EAE in the mouse involves additional loci outside the MHC.