PD-L2 protein identified as mechanism for senescent cell immune evasion

Researchers have identified the PD-L2 protein as a key factor that allows harmful senescent cells, often referred to as ‘zombie cells,’ to evade the immune system. According to a study published in the journal Cell Metabolism, these aging cells stop dividing but remain alive in tissues instead of being cleared away. This accumulation can trigger inflammation and disrupt the function of neighboring cells, contributing to various age-related health issues.

Dr. Selim Chaib, a medical research assistant at Cedars-Sinai Health Sciences University and co-author of the study, noted that PD-L2 helps these cells persist in the body despite the immune system's normal function of removing them. The discovery suggests that PD-L2 could serve as a therapeutic target to eliminate harmful senescent cells. Additionally, scientists believe the protein could function as a blood-based biomarker to detect and monitor the presence of these cells. In laboratory experiments, blocking PD-L2 was shown to reduce cellular senescence in mice.