A new treatment triggered immune cells to clear out toxic plaque buildup and slow progression of Alzheimer’s disease in monkeys, researchers claim.
NYU Grossman School of Medicine published findings Tuesday in the journal Brain, stemming from an investigation with elderly squirrel monkeys with significant signs of neurodegeneration.
Results indicated up to 59% fewer amyloid beta plaque deposits in the animals’ brains following treatment with CpG oligodeoxynucleotides (CpG ODN), versus untreated animals. Treated animals also saw a decline in toxic tau levels, a nerve fiber protein that can inflict damage to nearby tissue when disease alters its chemical structure.
“Our findings illustrate that this therapy is an effective way of manipulating the immune system to slow neurodegeneration,” Akash Patel, MS, an assistant research scientist in the Center for Cognitive Neurology at NYU Langone Health, said in a news release posted to EurekAlert.org.
Of 15 female elderly monkeys under study, aged 17 to 19 years old, eight were given a single dose of treatment monthly for two years, while the rest received saline solution. Researchers looked at the animals’ behavior, brain tissue and drew blood samples to assess levels of the toxic protein buildup and inflammation. The treated group outperformed their untreated counterparts when given puzzles, picking up puzzle-solving skills faster and performed the task on par with younger animals.
“Our new treatment avoids the pitfalls of earlier attempts because it is delivered in cycles, giving the immune system a chance to rest between doses,” Thomas Wisniewski, MD, study co-senior author, Gerald J. and Dorothy R. Friedman professor in the department of neurology and director of the Center for Cognitive Neurology at NYU Langone, said in the release. Researchers say other failed treatments overstimulated the brain and led to harmful inflammation, though according to Wisniewski, such damaging effects like added inflammation weren’t seen in the treatment group.
The Centers for Disease Control and Prevention (CDC) pins Alzheimer’s disease as the sixth leading cause of death. While the disease still has no cure, Biogen’s drug aducanumab recently won a controversial FDA authorization in the fight against Alzheimer’s, though experts say the drug likely wouldn’t bring much benefit to patients with severe courses of disease.
“The CpG ODN drugs are part of a class of innate immune regulators,” the release reads. The research team also claimed to be the first to use a drug administration technique called “pulsing” to keep away from excess inflammation.
The squirrel monkeys were said to be ideal for studying Alzheimer’s due to a similar progression of neurodegeneration associated with aging, as seen in humans.
“The similarities in aging between the animals studied and our own species give us hope that this therapy will work in human patients as well,” Henrieta Scholtzova, MD, Ph.D. study co-senior author, added in the release. She warned that only animals with significant signs of neurodegeneration were studied, and further studies will involve younger animals to explore the drug’s efficacy in earlier courses in disease.