ENCEPHALITOGENICITY OF MYELIN-ASSOCIATED OLIGODENDROCYTIC BASIC-PROTEIN AND 2',3'-CYCLIC NUCLEOTIDE 3'-PHOSPHODIESTERASE FOR BALB C AND SJLMICE/

In search of new encephalitogenic myelin antigens, the 2',3'-cyclic nu cleotide 3'-phosphodiesterase (CNP) and 19 000 MW isoform of myelin-as sociated oligodendrocytic basic protein (MOBP) were obtained as recomb inant proteins by the baculovirus expression system in Spodoptera frug iperda cells and purified to homogeneity by immobilized metal chelate affinity chromatography (IMAC). The purified MOBP was soluble in water and showed retarded migration on sodium dodecyl sulphate-polyacrylami de gel electrophoresis similar to myelin basic protein (MBP). MOBP ind uced experimental autoimmune encephalomyelitis (EAE) in nine of 15 sus ceptible SJL OlaHsd mice, causing death in two animals, whereas three of 14 BALB/c mice showed mild symptoms of EAE, manifested as transient weakness of hind limbs. In both mouse strains, periventricular infilt rates of mononuclear cells were observed. In addition, both 46 000 MW and 48 000 MW CNP isoforms were shown to be non-encephalitogenic for b oth mouse strains.