An experimental vaccine formulated to protect against Alzheimer’s has proven far more successful than other similar ’DNA vaccines’ against the disease, according to researchers at UT Southwestern Medical Center.
The vaccine is designed to protect against beta-amyloid, the small protein responsible for forming plaque in the brain and believed to play a role in the advancement of Alzheimer’s disease.
Compared with other DNA vaccines that researchers tested in an animal study, the new experimental vaccine stimulated over 10 times as many antibodies that can attach to and get rid of beta-amyloid.
“The antibody is specific; it binds to plaque in the brain. It doesn’t bind to brain tissue that does not contain plaque,” Dr. Rosenberg said, director of the Alzheimer’s Disease Center and senior author of the study.
“This approach shows promise in generating enough antibodies to be useful clinically in treating patients.”
A different approach was necessary when developing this vaccine. Although there was evidence in the triggering of an immune response when beta-amyloid itself was injected into the arm—including the creation of antibodies and other bodily defenses against beta-amyloid—serious side effects could occur.
In fact, the immune response to this type of vaccine sometimes caused significant brain swelling, so Dr. Rosenberg and his team focused on developing a nontraditional DNA vaccine.
The new DNA vaccine does not contain beta-amyloid itself but instead a portion of the beta-amyloid gene that codes for the protein.
During the current study, the research team coated mini gold beads with the beta-amyloid DNA and injected them into the skin of the animals’ ears.
Once inside the body, the DNA stimulated an immune response, including antibodies to beta-amyloid.
“After seven years developing this vaccine, we are hopeful it will not show any significant toxicity, and that we will be able to develop it for human use,” he said.
Upcoming studies will center on determining if the vaccine is safe and whether it protects mental function in animals, said Rosenburg.
The study was funded by the National Institutes of Health, The Rudman Foundation and the Alzheimer’s Association. The results of the study appear in the journal Vaccine.