MS therapy works in monkeys

Abstract

Researchers at the National Institute of Allergy and Infectious Diseases (NIAID) have found an antigen-specific immunotherapy that is effective in treating a disease similar to multiple sclerosis (MS) in monkeys (experimental allergic encephalomyelitis). Lead author of the study Michael Lenardo said ‘Current treatments for MS broadly suppress the immune system and cause toxic side effects. This treatment, specifically targets the T cells that cause the disease’. As it is known that high and repeated doses of antigen can lead to programmed cell death, the team evaluated the effect of administering repeated doses of myelin peptides to nine marmoset monkeys. Three monkeys received large doses of MP4, a chimeric, recombinant polypeptide containing human myelin basic protein and human proteolipid protein epitopes, three received moderate doses of MP4 and three received none. The monkeys were observed for 105 days. None of the monkeys in the high-dose group showed symptoms, two out of three in the moderate group had delayed symptoms and all three untreated monkeys had clinical symptoms. Central nervous system lesions were evaluated by magnetic resonance imaging of the animals’ brains. Severe damage to the myelin sheaths was found in two of the untreated monkeys and one monkey in the moderate group. Minor damage was also seen in the high dose group, indicating that disease activity had not been completely suppressed. Lead author of the study, Dr Lenardo, and colleagues are investigating if this therapy works in a mouse model of another autoimmune disease, myasthenia gravis. J. Immunol. (2001) 166, 2116–2121 HM