Alzheimer’s disease could be halted and even reversed by altering the brain’s immune system, groundbreaking research says.

New research gives hope to those suffering with dementia

Leading neurobiologist Professor Michal Schwartz said the findings were “very exciting” – and showed for the first time that a diseased brain was able to fight the debilitating condition.

Scientists saw a significant drop in the symptoms of dementia when they reduced the cells that prevent the immune system from reacting.

The study by experts at the Weizmann Institute of Science in Israel and published in journal Nature Communications, offers hope of a drug for the disease which affects about 850,000 people in Britain.

Mice were genetically engineered with human genes that are linked to dementia and made to learn the location of a platform in a rodent “swimming pool”.

Scientists then blocked the action of regulatory T cells which consequently allowed immune cells to enter the brain.

As a result, inflammation and clumps of “plaque” on the brain were reduced and the mice performed better in cognitive tests.

Prof Schwartz said: “Those who were given the therapy were almost as good at memorising the platform as normal mice – even though they already had symptoms of dementia.

“It means the therapy not only halted the condition but reversed it.”

The most common form of dementia, Alzheimer’s disease affects the body’s central nervous system.

Inflammation, damage to brain cells and abnormal protein build-up can cause devastating memory loss and inability to respond to the environment.

Researchers said the work highlighted the possibility of T cells as drug targets for future Alzheimer’s treatment.

Prof Schwartz said: “The concept is very exciting.

“We already have several molecules we believe could perform the same function in humans and we hope we will be able to reveal these in pre-clinical experiments by the end of the year.”