Changes in cathepsins B-1 and D, neutral proteinase and 2',3'-cyclic nucleotide-3'-phosphohydrolase activities in monkey brain with experimental allergic encephalomyelitis

Myelin basic protein modified with 2′-hydroxy-5′-nitrobenzylbromide or homologous monkey white matter was used to induce experimental allergic encephalomyelitis (EAE) in rhesus monkeys. Altogether 7 monkeys with and without EAE were studied. Macroscopic lesions (plaques), normal-appearing white matter of normal rhesus monkey brains were removed and assayed for cathepsins B-1 and D, neutral proteinase and 2′-3′-cyclic nucleotide-3′-phosphohydrolase activities. Lymph nodes from 2 monkeys, 1 with and 1 without EAE were also included in the present investigation.Cathepsins B-1 and D and neutral proteinase were significantly increased in lesion areas of EAE monkeys when compared with the findings in normal brain material. The enzyme 2′,3′-cyclic nucleotide-3′-phosphohydrolase was found to be significantly decreased in the lesions when compared to the normal-appearing white matter areas of the same animals. The change parallels the reduction of other well-established constituents of the myelin, giving support to the concept that the enzyme is a component of the myelin.The results of the enzyme assays are discussed in relation to the pathogenesis of CNS lesions in EAE.