Peripheral macrophages crossed the blood-brain barrier and eliminated 90% of plaque build up, according to Nature Medicine study.
Blocking a common immune system response cleared up plaques associated with Alzheimer’s disease and enabled treated mice to recover some lost memory, researchers report.
The team originally thought that blocking the immune system molecule TGFb (transforming growth factor) might actually increase the buildup of amyloid plaques associated with Alzheimer’s. Earlier studies found that patients tend to have elevated amounts of TGF-b, which plays a role in activating an immune system response to injury. Some hypothesized that the presence of the molecule was simply an attempt to quiet the inflammatory response caused by a buildup of plaque.
When TGF-b was blocked in peripheral immune cells of mice, the immune system seemed to unleash peripheral macrophages. The macrophages passed through the blood-brain barrier and surrounded the neurons and plaques in the mice.
The researchers found that as much as 90% of the plaques were eliminated from the brains of these mice. The mice also showed an improved ability to perform some tests including navigating mazes when compared to mice without TGF-b blocked. Scientists also found lower levels of other biological markers associated with the dementia.
The study was performed by investigators at Yale University, Saitama University, Johns Hopkins University, University of South Florida, and Cedars-Sinai Medical Center. The study is published May 30 in Nature Medicine.
