Bringing down the host: enteropathogenic and enterohaemorrhagic E scherichia coli effector‐mediated subversion of host innate immune pathways

Summary Enteric bacterial pathogens commonly use a type III secretion system ( T 3 SS ) to successfully infect intestinal epithelial cells and survive and proliferate in the host. Enteropathogenic and enterohaemorrhagic E scherichia coli ( EPEC ; EHEC ) colonize the human intestinal mucosa, form characteristic histological lesions on the infected epithelium and require the T 3 SS for full virulence. T 3 SS effectors injected into host cells subvert cellular pathways to execute a variety of functions within infected host cells. The EPEC and EHEC effectors that subvert innate immune pathways – specifically those involved in phagocytosis, host cell survival, apoptotic cell death and inflammatory signalling – are all required to cause disease. These processes are reviewed within, with a focus on recent work that has provided insights into the functions and host cell targets of these effectors.