June 13

BBC - A potential DNA vaccine for Alzheimer's disease has produced promising results in mice. In tests, it helped cut levels of key amyloid proteins thought to cause the disease by up to 50% in some parts of the brain. And unlike alternative vaccines in development, which use viruses, it produced no side effects. The Japanese study appears in the journal Proceedings of the National Academy of Sciences.

Over-production of amyloid proteins are thought to trigger symptoms of Alzheimer's by forming clumps that litter the brain. Previous studies have shown the immune system of mice is stimulated to attack these plaques if they are immunised with amyloid protein.

This approach has been tested in preliminary trials on humans, but immune response was too strong, leading to damaging swelling of the brain. The latest approach works by stimulating the body to produce small amounts of naked DNA that codes for these proteins, rather than relying on a special virus to get it into the cell.

This has the effect of producing a more gentle immune response, and importantly the DNA has also been designed so that it is not capable of replicating itself by incorporating itself into the human genome.