IL-1β, IL-18, and eicosanoids promote neutrophil recruitment to pore-induced intracellular traps following pyroptosis.
Inflammasomes activate caspase-1, initiating a lytic form of programmed cell death termed pyroptosis, which is an important innate immune defense mechanism against intracellular infections. We recently demonstrated in a mouse infection model of pyroptosis that instead of releasing bacteria into the extracellular space, bacteria remain trapped within the pyroptotic cell corpse, termed the pore-induced intracellular trap (PIT). This trapping mediates efferocytosis of the PIT and associated bacteria by neutrophils; bacteria are subsequently killed via neutrophil ROS. Using this pyroptosis model, we now show that the pro-inflammatory cytokines IL-1β and IL-18 and inflammatory lipid mediators termed eicosanoids are required for effective clearance of bacteria downstream of pyroptosis. We further show that IL-1β, IL-18, and eicosanoids affect this in part by mediating neutrophil recruitment to the PIT. This is in addition to our prior findings that complement is also important to attract neutrophils. Thus, the PIT initiates a robust and coordinated innate immune response involving multiple mediators that attract neutrophils to efferocytose the PIT and its entrapped bacteria.
Department of Microbiology and Immunology, Center for Gastrointestinal Biology and Disease, and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Ine
I
Jorgensen
Department of Microbiology and Immunology, Center for Gastrointestinal Biology and Disease, and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Joseph P
JP
Lopez
Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, University of Tübingen, Tübingen, Germany.
Stefan A
SA
Laufer
Department of Microbiology and Immunology, Center for Gastrointestinal Biology and Disease, and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Edward A
EA
Miao
D000818:Animals; D020170:Caspase 1 / Q000378:metabolism; D002465:Cell Movement; D002478:Cells, Cultured; D015777:Eicosanoids / Q000378:metabolism; D065206:Extracellular Traps / Q000276:immunology; D016908:Gram-Positive Bacterial Infections / Q000276:immunology*; D007113:Immunity, Innate; D058847:Inflammasomes / Q000378:metabolism; D020382:Interleukin-18 / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009504:Neutrophils / Q000276:immunology*; D018272:Porins / Q000378:metabolism; D000069292:Pyroptosis; D017382:Reactive Oxygen Species / Q000378:metabolism; D019779:Salmonella enterica / Q000276:immunology*
D015777:Eicosanoids; D058847:Inflammasomes; D020382:Interleukin-18; D053583:Interleukin-1beta; D018272:Porins; D017382:Reactive Oxygen Species; D020170:Caspase 1
Caspase-1; Inflammasome; Neutrophil recruitment; Pore-induced intracellular trap; Pyroptosis
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