Legionella pneumophila Infection and The Host Unfolded Protein Response

Legionella pneumophila is an environmental bacterium and the major cause of Legionnaires’ disease in humans. L. pneumophila replicates in alveolar macrophages within an endoplasmic reticulum-like compartment termed the Legionella-containing vacuole (LCV). LCV biogenesis depends on the secretion of bacterial virulence effector proteins that subvert an array of cellular processes. Here, we investigated the effect of L. pneumophila infection on the host ER-stress response. We found that ER-stress and the unfolded protein response limited bacterial replication by inducing the activation of interferon signalling through a novel mechanism. This work revealed a previously unrecognised link between ER-stress and the host cytokine response.