Hope for MS patients through understanding roots of the disease in monkeys

New research led by Scott W. Wong, Ph.D., senior scientist, Vaccine and Gene Therapy Institute; interim division chief, Division of Pathobiology and Immunology at the Oregon National Primate Research Center; and professor, OHSU’s Department of Molecular Microbiology and Immunology, describes the similarities between multiple sclerosis and a unique, spontaneous paralytic disease that occurs in nonhuman primates. This model opens the door to discovering the mechanisms driving MS in humans.

The model, called Japanese macaque encephalomyelitis, or JME, is an inflammatory demyelinating disease that occurs in a colony of Japanese macaques at OHSU’s Oregon National Primate Research Center and causes the clinical symptoms of MS: decreased mobility due to leg weakness or paralysis, and vision problems. JME is the only spontaneously occurring MS-like disease in nonhuman primates in the world. Other nonhuman models of MS are artificially induced by immunizing animals with myelin or myelin proteins.

The study, “Immunopathology of Japanese macaque encephalomyelitis is similar to multiple sclerosis,” is published in the Journal of Neuroimmunology.

Researchers found that JME encompasses several key signatures that are associated with MS. These findings cast new light on the cause and progression of MS in humans, and will enable researchers to identify and target pathways to treat people with MS. These types of studies are not otherwise feasible in patients with MS.

The researchers sought to determine if JME possesses features of an autoimmune-like disease in the central nervous system. They found that the central nervous system of animals with JME contain active lesions that harbor many of the important immunological signatures observed in MS that hints to MS being an autoimmune-like disease.

The JME model also holds great potential for verifying imaging techniques being developed by researchers to visualize and measure remyelination in humans. This paper demonstrates that researchers will be able to image the brains of the Japanese macaques using MRI, study the pathology of the JME lesions and verify the usefulness of new MRI techniques for studying MS in humans. Many MRI techniques being developed for MS cannot be verified using rodents, but can be verified in monkeys.

The cause of MS remains unknown. Importantly, this study paves the way for future studies aimed at determining whether the causes of JME and MS are similar or even identical.