Researchers at Cedars-Sinai have developed young immune cells from human stem cells that reversed signs of aging and Alzheimer's disease in mice. The treatment improved memory and brain structure in the animals. The findings, published in Advanced Science, suggest potential for personalized therapies against cognitive decline.
Scientists at Cedars-Sinai Medical Center have achieved a breakthrough by creating 'young' immune cells from human induced pluripotent stem cells, which reversed cognitive decline and Alzheimer's symptoms in laboratory mice. The study, published in the journal Advanced Science in 2025 (DOI: 10.1002/advs.202417848), focused on mononuclear phagocytes—immune cells that clear harmful substances but lose function with age.
Clive Svendsen, PhD, executive director of the Board of Governors Regenerative Medicine Institute and senior author, explained the innovation: "Previous studies have shown that transfusions of blood or plasma from young mice improved cognitive decline in older mice, but that is difficult to translate into a therapy. Our approach was to use young immune cells that we can manufacture in the lab—and we found that they have beneficial effects in both aging mice and mouse models of Alzheimer's disease."
When infused into aging mice and those modeling Alzheimer's, the cells led to notable improvements. Treated mice performed better on memory tests and showed increased numbers of mossy cells in the hippocampus, a key area for learning and memory. Alexandra Moser, PhD, lead author and project scientist in the Svendsen Lab, noted: "The numbers of mossy cells decline with aging and Alzheimer's disease. We did not see that decline in mice receiving young mononuclear phagocytes, and we believe this may be responsible for some of the memory improvements that we observed."
Additionally, the brains of treated mice had healthier microglia, with preserved long, thin branches essential for detecting and clearing damaged tissue. The cells did not enter the brain directly, suggesting indirect benefits, possibly via anti-aging proteins, extracellular vesicles, or removal of pro-aging factors from the blood.
Jeffrey A. Golden, MD, executive vice dean for Education and Research, highlighted the potential: "Because these young immune cells are created from stem cells, they could be used as personalized therapy with unlimited availability. These findings show that short-term treatment improved cognition and brain health, making them a promising candidate to address age- and Alzheimer's disease-related cognitive decline."
The research was supported by the Universal Sunlight Foundation, the Cedars-Sinai Center for Translational Geroscience, and the Cedars-Sinai Board of Governors Regenerative Medicine Institute. Additional authors include Luz Jovita Dimas-Harms, Rachel M. Lipman, and others.