GENE VACCINE FOR ALZHEIMER'S

DNA vaccination is a proposed experimental technique for protecting an organism against disease by injecting it with naked DNA to produce an immunological response.

What is the point of this?

The gene is made artificially, and can therefore be much more pure than any vaccine made directly from pathogens.

Doses of DNA-gene-coated gold particles protect mice against a protein implicated in Alzheimer's disease, researchers at UT Southwestern Medical Center have found.

By pressure-injecting the gene responsible for producing the specific protein - called amyloid-beta 42 - the researchers caused the mice to make antibodies and greatly reduce the protein's build-up in the brain. Accumulation of amyloid-beta 42 in humans is a hallmark of Alzheimer's disease.

"The whole point of the study is to determine whether the antibody is therapeutically effective as a means to inhibit the formation of amyloid-beta storage in the brain, and it is," said Dr. Roger Rosenberg, the study's senior author and director of the Alzheimer's Disease Center at UT Southwestern.

"Previous Alzheimer’s vaccines were protein-based," said Dr. Baoxi Qu, the study’s lead author and assistant professor in the Center for Biomedical Inventions and internal medicine. "We wanted to try a DNA-based genetic vaccine instead to see if we could enhance the immune response."

The key in the UT Southwestern study was finding another way to vaccinate patients without stimulating the body’s own immune cytotoxic T cells, said Dr. Roger Rosenberg, a study author and director of the Alzheimer’s Disease Center. "This dilemma was discussed with my colleagues, and we decided to try vaccination with an amyloid gene, rather than the amyloid protein vaccine," said Dr. Rosenberg.

Current treatments for Alzheimer’s disease focus on the symptoms since no therapies have been clinically proven to slow or prevent progression of the disease. Amyloid protein deposits are present in the early phase of the disease – a fact that suggests a gene vaccination would be a step forward in slowing the progression of dementia.

Other UT Southwestern authors involved in the study were Dr. Liping Li, a research fellow in the Center for Biomedical Inventions; and Dr. Philip Boyer, assistant professor of pathology.