This study evaluated whether PD-L2 acts as an immune checkpoint on senescent cells to promote their persistence during aging, using senescent human cells in vitro, PD-L2 knockout mice, and anti-PD-L2 therapy in aged wild-type mice.
Old PD-L2 knockout mice accumulated fewer senescent cells than wild-type controls, with greater insulin sensitivity and grip strength; anti-PD-L2 therapy also restored insulin sensitivity in aged wild-type mice.
Findings are largely preclinical (mouse models and isolated human cells), with no human clinical trial data; long-term safety and off-target effects of anti-PD-L2 therapy in non-cancer contexts are not assessed; specific senescent cell subtypes targeted are not fully characterized.
While not yet clinically actionable, PD-L2 blockade is a promising senolytic strategy that may reduce senescent cell burden and improve metabolic and physical function in aging — watch for early-phase trials in this space.
