STUDIES ON AUTOIMMUNE ENCEPHALOMYELITIS IN GUINEA-PIG .2. INVITRO INVESTIGATION ON NATURE, PROPERTIES, AND SPECIFICITY OF SERUM-DEMYELINATING FACTOR

Abstract

Complement-dependent demyelinating activity of whole brain homogenate (WBH)-induced experimental allergic encephalomyelitis (EAE) sera was tested on long term tissue cultures of in vitro myelinated fetal guinea pig cerebellum. Complement-fixing (CF) auto-antibodies were the responsible agents, as demonstrated in experiments where all reagents belonged to the same species [guinea pigs of outbred (Hartley) and even of inbred (S2 or S13) strains]. These antibodies were of the IgG2 [immunoglobulin G2] class as shown by Sephadex G-200 and DEAE cellulose fractionation experiments. The corresponding auto-antigen was present in the homogenate and myelin of the CNS tissue. It was different from the encephalitogenic basic protein of CNS myelin (BP), as shown in experiments where the demyelinating auto-antibodies were induced, detected and absorbed by WBH or by CNS myelin, but not by BP. They were neither induced by nor cross-reacting with cerebroside and peripheral nervous system (PNS) tissue.