University of Toronto researchers develop potent vaccine for Alzheimer's

December 19, 2000

Researchers in the University of Toronto's Faculty of Medicine have discovered that a vaccine may help prevent and treat the disabling memory loss and cognitive impairment (dementia) of Alzheimer's disease.

Alzheimer's occurs when toxic biochemical compounds known as amyloid ß peptides accumulate in the brain, forming amyloid plaque deposits and injuring nerve cells, eventually causing dementia. While previous studies have shown that vaccinating transgenic mice with this peptide could remove the amyloid plaques, there was never any evidence of improvement in brain function.

After developing transgenic mice with amyloid plaques and cognitive impairment similar to those found in human Alzheimer's, scientists at U of T's Centre for Research in Neurodegenerative Diseases (CRND) determined that immunization with amyloid ß peptides blocked both the production of the plaques and learning impairment.

"Not only were we able to clean up the brain tissue, but we also prevented the behavioural consequences of Alzheimer's," says Dr. Peter St George-Hyslop, director of the CRND and a neurologist at the University Health Network. "Obviously, it is more important that a treatment or prevention in humans be able to block the clinical dementia." St George-Hyslop and his colleagues say the amyloid ß peptide vaccination is ready to be tested on humans. "Our results also show that pharmaceutical treatments that are directed at blocking the formation of the peptide or that accelerate its removal might also be good ways to treat Alzheimer's either alone or in conjunction with other interventions like vaccination," says Christopher Janus, research associate at the CRND and the study's first author. "In the future there might be a cocktail of treatments including drugs which block formation and inhibit the toxicity and then a vaccination which will remove the plaque."

The researchers believe this study provides the final element of proof that Alzheimer's is initiated by amyloid ß peptides. "While there are other factors that play a role in the development of the disease, there is little doubt that these peptides initiate the process," says David Westaway, associate professor of laboratory medicine and pathobiology in the Faculty of Medicine and one of the study's co-authors. "If results from our laboratory studies hold true in humans, this vaccine might well play a key part in eradicating the disabling dementia that is associated with the disease, whether caused by genetic or environmental factors."

The next step will be for pharmaceutical manufacturers to conduct preliminary trials on the safety of the vaccination, before larger scale testing can begin on its therapeutic effectiveness. The researchers believe clinical trials could begin on human subjects within the year.
-end-
Over the past decade, researchers at U of T's Centre for Research in Neurodegenerative Diseases (http://www.utoronto.ca/crnd/) have made a number of fundamental discoveries which have had a significant impact on our understanding of Alzheimer's and other neurodegenerative diseases. Earlier this year they discovered a new gene, Nicastrin, involved in the biochemical processes involved in amyloid ß peptide production. In 1995 they identified two defective genes that cause aggressive early-onset forms of Alzheimer's (Presenilin 1 and Presenilin 2) and in 1990, they were the first to show Alzheimer's is a complex disorder with many causes, some of which are genetic.

This study, to be published in the Dec. 21-28 issue of Nature, was supported by the Alzheimer Society of Ontario, the Canadian Institutes of Health Research, The W. Garfield Weston Foundation, the Howard Hughes Medical Research Foundation and the US National Institute of Aging.

CONTACT:
Steven de Sousa U of T Public Affairs
416-978-5949
steven.desousa@utoronto.ca

University of Toronto

Related Dementia Articles from Brightsurf:

The danger of Z-drugs for dementia patients
Strong sleeping pills known as 'Z-drugs' are linked with an increased risk of falls, fractures and stroke among people with dementia, according to new research.

The long road to dementia
Alzheimer's disease develops over decades. It begins with a fatal chain reaction in which masses of misfolded beta-amyloid proteins are produced that in the end literally flood the brain.

Why people with dementia go missing
People with dementia are more likely to go missing in areas where road networks are dense, complicated and disordered - according to new research from the University of East Anglia.

PTSD may double risk of dementia
People who have experienced post-traumatic stress disorder (PTSD) are up to twice as likely to develop dementia later in life, according to a new study by UCL researchers, published in the British Journal of Psychiatry.

Dementia education
School-based dementia education could deliver much needed empathy and understanding for older generations as new research from the University of South Australia shows it can significantly improve dementia knowledge and awareness among younger generations.

Building dementia friendly churches
A project to help church communities become more 'dementia friendly' has had a significant impact across the country.

A "feeling" for dementia?
A research team led by the DZNE concludes that personal perception can be an important indicator for the early detection of Alzheimer's disease.

New biomarker for dementia diagnosis
Medical researchers in the UK and Australia have identified a new marker which could support the search for novel preventative and therapeutic treatments for dementia.

Digital solutions for dementia care
Telehealth delivery of dementia care in the home can be as effective as face-to-face home visit services if carers and recipients take advantage of the technologies available, Australian researchers say.

Despite a marked reduction in the prevalence of dementia, the number of people with dementia is set to double by 2050 according to new Alzheimer Europe report
Today, at a European Parliament lunch debate, Alzheimer Europe launched a new report presenting the findings of its collaborative analysis of recent prevalence studies and setting out updated prevalence rates for dementia in Europe.

Read More: Dementia News and Dementia Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.