A new genetic clue in Alzheimer’s may be hiding in the brain’s immune cells
Researchers at Boston Children’s Hospital and collaborators report that microglia, the brain’s resident immune cells, can accumulate mutations in cancer-driving genes without turning cancerous. Instead, the team found evidence that these altered cells may help create the inflammatory conditions associated with Alzheimer’s disease.
The work, published in Cell, adds an unexpected layer to the Alzheimer’s puzzle. Rather than focusing only on hallmark protein buildups such as amyloid and tau, the study points toward a cellular selection process in which certain mutated immune cells may gain a survival advantage in the diseased brain. The result, according to the researchers, could be a more hostile environment for neurons.
What the team examined
The researchers sequenced 149 cancer-driving genes in tissue from 190 donated brains from people with Alzheimer’s disease and compared those findings with 121 healthy brains. The Alzheimer’s samples contained more single-letter DNA changes than the healthy tissue. More importantly, the mutations were not randomly scattered: the same five cancer driver genes appeared repeatedly.
That pattern suggests the changes are not simply background wear and tear from aging. Instead, the mutated microglia may be undergoing a kind of selection process. In an environment shaped by Alzheimer’s pathology, those cells may survive and proliferate better than neighboring cells, potentially reinforcing inflammation over time.
