Potatoes May Hold Key To Alzheimer's Vaccine

Alzheimer's disease (AD) is debilitating and one that robs people of their very essence - their minds. People with the disease generally succumb to dementia, memory loss, and ultimately the brain no longer can regulate normal body functions that lead to death. Researchers have been looking to discover a vaccine that would protect people from the disease.

Researchers at Case Western Reserve University appear to have made a breakthrough, by using a potato virus to produce amyloid beta proteins. It is hypothesized that amyloid beta proteins are responsible for AD.

Studies in mice have demonstrated that vaccinations with the amyloid beta protein (believed to be a major AD contributor) to produce Aβ antibodies can slow disease progression and improve cognitive function, possibly by promoting the destruction of amyloid plaques. Some early human trials have likewise been promising, but had to be halted due to the risk of autoimmune encephalitis.

One way to make Alzheimer's vaccinations safer would be to use a closely-related, but not human, protein as the vaccine, much like cowpox virus is used for smallpox immunizations.

In the August 15 Journal of Biological Chemistry, Robert Friedland and colleagues used this concept on an amyloid-like protein found in potato virus (PVY). They injected PVY into mice followed by monthly boosters for four months. The researchers found that the mice produced strong levels of antibodies that could attach to amyloid beta protein both in both solution and in tissue samples of Alzheimer's patients. And although the levels were lower, mice also developed Aβ antibodies if given injections of PVY-infected potato leaf as opposed to purified PVY.

This doesn't necessarily mean that the vaccine is right around the corner. There are still hurdles, including the possibility that amyloid beta proteins are a symptom, rather than a cause of the disease.

Friedland also hypothesizes that "immune responses generated from dietary exposure to proteins homologous to Aβ may induce antibodies that could influence the normal physiological processing of the protein and the development or progression of AD."