AUTHOR=Krause Kathrin , Amer Amal O. 

TITLE=Caspase Exploitation by Legionella pneumophila

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00515

DOI=10.3389/fmicb.2016.00515

ISSN=1664-302X

ABSTRACT=<p><italic>Legionella pneumophila</italic> remains a major health concern, especially for hospitalized patients. <italic>L. pneumophila</italic> in the environment can survive extracellular or as protozoan parasite within amoeba. After human infection it efficiently replicates in alveolar macrophages without activating inflammasome assembly and cleavage of caspase-1. In contrast murine macrophages actively recognize intracellular <italic>L. pneumophila</italic> via inflammasome components which initiate pro-inflammatory cytokine secretion, phagosomal maturation and pyroptotic cell death thereby leading to bacterial restriction. During this process flagellin-dependent and -independent signaling pathways trigger the canonical as well as the non-canonical inflammasome. This review describes the current knowledge about <italic>L. pneumophila</italic>-induced inflammasome pathways in permissive and restrictive host cells.</p>