Cell study points to new antibiotic strategy

A study in Cell shows granzyme B (GrB; GZMB), an immune cell protease, kills diverse bacterial species by shutting down multiple conserved survival pathways. The authors suggest compounds that mimic the protease’s mechanism could treat a broad spectrum of infections while avoiding the resistance that plagues conventional antibiotics, which target one pathway at a time.

T cells and NK cells secrete GrB together with pore-forming proteins such as perforin 1 (PRF1) or granulysin (GNLY); these create holes in target cell membranes through which GrB enters and kills the cell. While GrB was known to kill bacteria via processes involving reactive oxygen species (ROS), its mechanisms of ROS-independent killing were unclear...