title: Mycobacterium tuberculosis and the host cell inflammasome: a complex relationship.
abstract: The production of IL-1β during the infection with Mycobacterium tuberculosis (Mtb) is important for successful host immune defense. In macrophages and dendritic cells the host cell inflammasome is crucial for generation of secreted IL-1β in response to Mtb infections. In these cell types Mtb infection only activates the NLRP3-inflammasome. New reports demonstrate that nitric oxide has an important function in the negative regulation of the NLRP3-inflammasome to reduce tissue damage during Mtb infections. The type I interferon, IFN-β, is induced after Mtb infections and can also suppress NLRP3-inflammasome activation. In contrast, IFN-β increases activity of the AIM2-inflammasome after infection with intracellular pathogens such as Francisella tularensis and Listeria monocytogenes. Recent results demonstrate that non-tuberculous mycobacteria but not virulent Mtb induce the AIM2-inflammasome in an IFN-β dependent matter. Indeed, Mtb inhibits AIM2-inflammasome activation via its ESX-1 secretion system. This novel immune evasion mechanism may help Mtb to allow the induction of low levels of IFN-β to suppress the NLRP3-inflammasome without activating the AIM2-inflammasome.
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland College Park, MD, USA.
authors.forename: Volker
authors.initials: V
authors.lastname: Briken
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Ahlbrand
authors.forename: Swati
authors.initials: S
authors.lastname: Shah
mesh_terms: D003713:Dendritic Cells / Q000276:immunology* / Q000382:microbiology; D054884:Host-Pathogen Interactions; D057131:Immune Evasion; D058847:Inflammasomes / Q000276:immunology* / Q000378:metabolism*; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology; D009169:Mycobacterium tuberculosis / Q000276:immunology*
chemical_list: D058847:Inflammasomes
keywords: AIM2; ESX-1; IFN-β; IL-1β; Mycobacterium tuberculosis; NLRP3; inflammasome