Immune Cells Derived from Stem Cells May Reverse Age-Related Brain Changes and Alzheimer’s Signs

Researchers at Cedars-Sinai Medical Center have discovered that 'young' immune cells, generated from human stem cells, can reverse signs of aging and neurodegeneration in the brains of laboratory mice. Published in the journal Advanced Science, this preclinical study highlights the potential of harnessing immune cell therapy to combat cognitive decline associated with aging and Alzheimer's disease.

The study focused on mononuclear phagocytes—immune cells responsible for clearing harmful substances from the body, which typically decline in effectiveness with age. Scientists used pluripotent stem cells, which are adult cells reverted to an early embryonic state, to produce youthful versions of these immune cells. When infused into aging mice or models of Alzheimer’s, these cells produced notable improvements.

Mice treated with these young immune cells demonstrated better memory performance in behavioral tests and showed increased numbers of mossy cells in the hippocampus—a critical region for learning and memory. Additionally, the microglia, which act as the brain’s resident immune cells, remained healthier with more extensive branching, indicating preserved function.

Interestingly, the young immune cells did not appear to directly enter the brain, suggesting their beneficial effects might be mediated through indirect mechanisms, such as releasing protective proteins or extracellular vesicles into the bloodstream that influence brain health.

This research opens the door for developing personalized immune cell therapies from stem cells, offering an unlimited source of treatment candidates. The findings suggest that short-term interventions with these cells could significantly improve cognition and neural health, paving the way for future clinical trials in humans.

The study's authors believe that such therapies could provide promising new strategies for addressing age-related cognitive decline and neurodegenerative diseases like Alzheimer’s, by restoring immune function and brain health.

For more details, see the original publication in Advanced Science: DOI: 10.1002/advs.202417848.