Amyloid-β fibrils propagate from yeast surfaces and capture C. albicans in culture medium.D.K.V. KUMAR ET AL., SCIENCE TRANSLATIONAL MEDICINE Plaques of amyloid-β peptides in certain parts of the brain are a telltale sign of Alzheimer’s disease–associated neurodegeneration. When not in pathological aggregates, these peptides—found in healthy brains at low levels—are commonly considered inefficiently cleared catabolic byproducts. Now, researchers at Harvard and Massachusetts General Hospital (MGH) and their colleagues have shown that amyloid-β can protect against yeast and bacterial infections in two animal models, as well as in cultured human cells. Amyloid-β was able to bind carbohydrates on the surfaces of microbes, preventing the invaders from binding host cells. The team’s findings, published today (May 25) in Science Translational Medicine, suggest that amyloid-β may function similarly to antimicrobial peptides of the innate immune system.
“This is quite good and convincing work that confirms host defense activity of amyloid-β against fungal and bacterial infections in animal models, and begins to unravel the mechanisms of antimicrobial activity of the protein,” said Kevan Hartshorn who studies innate immunity at the Boston University School of Medicine and was not involved in the study.
“Amyloid-β is overdue for an update,” said Douglas Ethell, a neuroscientist at Western University of Health Sciences in California who was not involved in the work. “For too long it’s been viewed as a useless byproduct that wreaks havoc on the human brain. This paper adds to a growing body of evidence that amyloid-β serves important physiological roles that we are only now beginning to understand.”
Rudolph Tanzi and Robert ...
