Alzheimer's vaccine 'promising'

Alzheimer's vaccine 'promising'

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.


This work represents a promising new line of vaccine development
Dr Clive Holmes

Over-production of amyloid proteins are thought to trigger

symptoms of Alzheimer's by forming clumps that litter the brain.

Previous studies have shown that it is possible to stimulate the

immune system of mice to attack these plaques if they are

immunised with amyloid protein.

This approach has been tested in preliminary trials on humans,

but early results showed that the immune response was too strong,

leading to damaging swelling of the brain, as well as plaque

destruction.

New studies in man are currently underway that hope to mobilise

the immune response in a less aggressive manner so that plaques

are destroyed, but brain swelling is avoided.

Gentle response

The latest approach, developed by a team at Tokyo Metropolitan

Institute for Neuroscience, works by stimulating the body to

produce small amounts of amyloid protein itself.

Mice are injected with 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.

In tests, the latest vaccine reduced the deposition of amyloid

proteins by between 15.5% and 38.5% compared with untreated mice.

Deposition in specific areas of the brain - the cerebral cortex

and hippocampus - was reduced 40%-50%.

The researchers suggest that DNA vaccines of the type they have

produced could provide a cheap and effective strategy for

treating Alzheimer's in future.

Dr Clive Holmes, of the Alzheimer's Research Trust, said the

Toyko study held great promise.

He said: "This work represents a promising new line of vaccine

development but more research would be needed to see if this

could be replicated safely in humans."

Dr Susanne Sorensen, of the Alzheimer's Society, agreed that the

fact that the vaccine appeared safe was significant.

She said: "The findings support the idea that a vaccine is our

best hope for fighting this devastating disease for which there

is currently no cure."

( note: It is not surprising to observe new virus origin at

later study. DNA or protein origin with link to virus is a way to

trigger immune or antibody reaction thus to protect host. However

side-effect may appear much later like prion protein case...it

may happen 10 to 30 years from now...be ware.. it is possible)


file c12 James Chong/ 40-A Jalan Mendu, Kuching , Borneo