Amyloid-β peptide protects against microbial infection in mouse and worm models of Alzheimer's disease

Abstract

The amyloid-bβ peptide (Abβ) is a key protein in Alzheimer's disease (AD) pathology. We previously reported in vitro evidence suggesting that Ab is an antimicrobial peptide. We present in vivo data showing that Aβ expression protects against fungal and bacterial infections in mouse, nematode, and cell culture models of AD. We show that Aβ oligomerization, a behavior traditionally viewed as intrinsically pathological, may be necessary for the antimicrobial activities of the peptide. Collectively, our data are consistent with a model in which soluble Aβ oligomers first bind to microbial cell wall carbohydrates via a heparin-binding domain. Developing protofibrils inhibited pathogen adhesion to..