Gert van der Hoek
In Memoriam - Editor, Senior Moderator
UCI mouse study finds dramatic increase in brain plaques when key cells are lacking
Feb. 23, 2016 — Immune cells that normally help us fight off bacterial and viral infections may play a far greater role in Alzheimer’s disease than originally thought, according to University of California, Irvine neurobiologists with the Sue & Bill Gross Stem Cell Research Center and the Institute for Memory Impairments and Neurological Disorders.
The researchers discovered this when Alzheimer’s disease mice genetically modified to lack these key immune cells in their blood developed the distinctive brain plaques associated with the neurodegenerative disorder much more quickly.
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Alzheimer’s is the leading cause of age-related dementia and is thought to be driven by the accumulation of a protein called beta-amyloid that aggregates to form amyloid plaques in the brain. Microglia, immune cells that reside in the brain, attempt to clear this buildup, but in Alzheimer’s, they appear to be fighting a losing battle. While many studies have explored the role of microglia in Alzheimer’s, very few researchers have asked whether a different set of immune cells called T-cells and B-cells that reside outside the brain and play a large part in autoimmune diseases might also impact Alzheimer’s.
To test this idea, Blurton-Jones and Marsh bred genetically modified Alzheimer’s disease mice to lack three key immune cell types: T-cells, B-cells and NK-cells. Six months later, when the brains of these mice were compared to those of Alzheimer’s mice with intact immune systems, the scientists found a more than twofold increase in beta-amyloid accumulation.
“We were very surprised by the magnitude of this effect,” Blurton-Jones said. “We expected the influence of the deficient immune system on Alzheimer’s pathology to be much more subtle.”
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Feb. 23, 2016 — Immune cells that normally help us fight off bacterial and viral infections may play a far greater role in Alzheimer’s disease than originally thought, according to University of California, Irvine neurobiologists with the Sue & Bill Gross Stem Cell Research Center and the Institute for Memory Impairments and Neurological Disorders.
The researchers discovered this when Alzheimer’s disease mice genetically modified to lack these key immune cells in their blood developed the distinctive brain plaques associated with the neurodegenerative disorder much more quickly.
(..............)
Alzheimer’s is the leading cause of age-related dementia and is thought to be driven by the accumulation of a protein called beta-amyloid that aggregates to form amyloid plaques in the brain. Microglia, immune cells that reside in the brain, attempt to clear this buildup, but in Alzheimer’s, they appear to be fighting a losing battle. While many studies have explored the role of microglia in Alzheimer’s, very few researchers have asked whether a different set of immune cells called T-cells and B-cells that reside outside the brain and play a large part in autoimmune diseases might also impact Alzheimer’s.
To test this idea, Blurton-Jones and Marsh bred genetically modified Alzheimer’s disease mice to lack three key immune cell types: T-cells, B-cells and NK-cells. Six months later, when the brains of these mice were compared to those of Alzheimer’s mice with intact immune systems, the scientists found a more than twofold increase in beta-amyloid accumulation.
“We were very surprised by the magnitude of this effect,” Blurton-Jones said. “We expected the influence of the deficient immune system on Alzheimer’s pathology to be much more subtle.”
“We found that in Alzheimer’s mice with intact immune systems, antibodies – which are made by B-cells – accumulated in the brain and associated with microglia. This, in turn, helped increase the clearance of beta-amyloid,” Marsh said.
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