Project description:Analysis of ALR-deficient cells indicates that ALRs are not required for the IFN response to intracellular DNA. To explore whether AIM2-like receptors activated another innate signaling pathway upon DNA detection, we performed microarray analysis comparing ALR+/+, ALR-/-, and AIM2-/- macrophages and fibroblasts 4 or 8 hours after transfection with calf-thymus DNA. Total RNA was isolated from ALR+/+, ALR-/-, and AIM2-/- bone marrow-derived macrophages (BMMs) or fibroblasts (MEFs) mock-treated (lipofectamine alone) or transfected with 5ug CT-DNA for 4 or 8 hours.
Project description:Analysis of ALR-deficient cells indicates that ALRs are not required for the IFN response to intracellular DNA. To explore whether AIM2-like receptors activated another innate signaling pathway upon DNA detection, we performed microarray analysis comparing ALR+/+, ALR-/-, and AIM2-/- macrophages and fibroblasts 4 or 8 hours after transfection with calf-thymus DNA.
Project description:Inflammasomes are critical for mounting host defense against pathogens. The molecular mechanisms that control activation of the AIM2 inflammasome in response to different cytosolic pathogens remain unclear. Here we found that the transcription factor IRF1 was required for the activation of the AIM2 inflammasome during infection with the Francisella tularensis subspecies novicida (F. novicida), whereas engagement of the AIM2 inflammasome by mouse cytomegalovirus (MCMV) or transfected double-stranded DNA did not require IRF1. Infection of F. novicida detected by the DNA sensor cGAS and its adaptor STING induced type I interferon-dependent expression of IRF1, which drove the expression of guanylate-binding proteins (GBPs); this led to intracellular killing of bacteria and DNA release. Our results reveal a specific requirement for IRF1 and GBPs in the liberation of DNA for AIM2 sensing depending on the pathogen encountered by the cell. We used microarrays to explore the gene expression profiles differentially expressed in Francisella-infected bone marrow-derived macrophages (BMDMs) isolated from Irf1-/-, Ifnar1-/-, Aim2-/- and wild-type mice.
Project description:Inflammasomes are critical for mounting host defense against pathogens. The molecular mechanisms that control activation of the AIM2 inflammasome in response to different cytosolic pathogens remain unclear. Here we found that the transcription factor IRF1 was required for the activation of the AIM2 inflammasome during infection with the Francisella tularensis subspecies novicida (F. novicida), whereas engagement of the AIM2 inflammasome by mouse cytomegalovirus (MCMV) or transfected double-stranded DNA did not require IRF1. Infection of F. novicida detected by the DNA sensor cGAS and its adaptor STING induced type I interferon-dependent expression of IRF1, which drove the expression of guanylate-binding proteins (GBPs); this led to intracellular killing of bacteria and DNA release. Our results reveal a specific requirement for IRF1 and GBPs in the liberation of DNA for AIM2 sensing depending on the pathogen encountered by the cell.
