Researchers identify mechanisms behind zombie cells and bacteria

New biological studies have identified unique survival mechanisms in both human cells and bacteria that allow them to persist or function after death.

At Cedars-Sinai Medical Center, researchers discovered that senescent cells, often called “zombie cells,” use the PD-L2 protein as an invisibility cloak to evade the immune system. While senescence is a protective response to prevent damaged cells from becoming cancerous, the accumulation of these cells releases inflammatory molecules that contribute to age-related decline and insulin resistance. The study suggests that targeting this protein could help the body clear these cells more effectively.

Separately, biologists at Aarhus University discovered a phenomenon in bacteria where DNA replication continues after the cell has died. By starving specific bacterial species, researchers activated dormant phage DNA, causing the bacteria to burst and release their contents into a biofilm. This process allows the bacteria to continue producing DNA folded into specialized G-quadruplex structures, which could potentially be harnessed for chemical catalysis and biotechnology applications.