Scientists discover how harmful “zombie cells” hide from the immune system

Scientists have discovered a protein that may help harmful aging cells hide from the immune system, allowing them to accumulate and fuel age-related health problems. Blocking the protein in mice reduced these cells and inflammation while improving blood sugar regulation and strength, offering a promising new direction for anti-aging research. Researchers led by Cedars-Sinai Health Sciences University have discovered a protein that may allow harmful aging cells to escape detection by the immune system. By helping these cells remain in the body instead of being cleared away, the protein could contribute to their accumulation and the development of health problems associated with aging. The discovery, published in Cell Metabolism, identifies PD-L2 as a potential target for therapies aimed at eliminating harmful aging cells.

Scientists also believe the protein could serve as a blood marker, providing a way to detect and monitor these cells. "Our findings suggest that PD-L2 may help aging cells stay in the body when they would normally be removed by the immune system," said Selim Chaib, PhD, research assistant professor of Medicine at Cedars-Sinai and first and co-corresponding author of the study. As cells age or become damaged, some enter a state known as senescence. These cells stop dividing but remain alive, lingering in tissues rather than