If lab research on mice holds true for people, researchers may have discovered a way to stimulate the brain’s natural defense mechanisms in people with Alzheimer’s disease.
Experts say the new finding opens the door to the development of a treatment for Alzheimer’s disease and a vaccine to prevent the illness.
The research is presented in an early online edition of the Proceedings of the National Academy of Sciences.
One of the main characteristics of Alzheimer’s disease is the production in the brain of a toxic molecule known as amyloid beta. Microglial cells, the nervous system’s defenders, are unable to eliminate this substance, which forms deposits called senile plaques.
The team led by Serge Rivest, Ph.D., professor at Université Laval’s Faculty of Medicine in Canada, identified a molecule that stimulates the activity of the brain’s immune cells.
The molecule, known as MPL (monophosphoryl lipid A), has been used extensively as a vaccine adjuvant by pharmaceutical company Glaxo Smih Kline for many years, and its safety is well established. A vaccine adjuvant is a substance that is added to the vaccine to increase the body’s immune response to the vaccine.
Researchers gave mice with Alzheimer’s symptoms weekly injections of MPL over a 12-week period and discovered 80 percent of senile plaques were eliminated.
In addition, tests measuring the mice’s ability to learn new tasks showed significant improvement in cognitive function over the same period.
If the product is deemed beneficial in human subjects, researchers envision two potential uses for MPL. First, it could be administered by intramuscular injection to people with Alzheimer’s disease to slow the progression of the illness.
Alternatively, it could also be incorporated into a vaccine designed to stimulate the production of antibodies against amyloid beta.
“The vaccine could be given to people who already have the disease to stimulate their natural immunity,” said Rivest. “It could also be administered as a preventive measure to people with risk factors for Alzheimer’s disease.”
“When our team started working on Alzheimer’s disease a decade ago, our goal was to develop better treatment for Alzheimer’s patients,” Rivest said.
“With the discovery announced today, I think we’re close to our objective.”
Source: Université Laval