Combating Alzheimer's by Restoring the Brain's Clean-up Crew

A study published in Nature found CD22 — a B-cell receptor that governs immune responses — to be a negative controller of microglial phagocytosis, which might improve cognitive function in people with Alzheimer's, reports Fierce Biotech . The researchers tested nearly 3,000 genes that are currently targetable with drugs for clues as to which ones might play a role in age-related decline in microglial phagocytosis. They inhibited each gene to observe its effects on mice's microglia while also examining the hippocampus to ascertain what genetic changes are happening in young and old animals. Older microglia generated more copies of CD22 than younger ones, and blocking CD22 promoted microglial phagocytosis. The team continuously infused CD22 antibodies on both sides of mice's brains, and a month later the CD22-inhibited aged mice exhibited improved spatial memory and associative memory in two tests versus the control mice. "CD22 is a new target we think can be exploited for treatment of neurodegenerative diseases," declared Stanford University's Tony Wyss-Coray.