Experimental allergic encephalomyelitis mediated by murine encephalitogenic T cell lines specific for myelin proteolipid apoprotein.

T cell lines specific for bovine myelin proteolipid apoprotein (PLP) were established from SJL/J mice. The line cells bore surface phenotypes of T helper/inducer cells (Lyt-1+, Lyt-2-, L3T4+) and responded well to bovine, rat, and guinea pig PLP but not to myelin basic protein. One line responded to major PLP, and another responded to both major PLP and DM-20, which are the two major intrinsic membrane proteins of the central nervous system (CNS) myelin. Intraperitoneal inoculation of 4 to 30 X 10(6) PLP-activated line cells followed by injection of pertussis vaccine induced acute inflammatory disease of the CNS, with typical clinical signs of EAE mostly in a week in recipient mice that had been treated with low-dose irradiation. Almost all animals recovered completely, and two of the 12 animals relapsed 42 or 75 days after inoculation. The lesions were restricted to the CNS and were characterized by perivascular and parenchymal infiltration of inflammatory cells, fibrin deposit, and demyelination. In the severe lesions, axons were also damaged. These observations suggest that PLP is a definite encephalitogen, and PLP-sensitized effector T cells induce inflammatory demyelination in the CNS.