Project description:Innate immune PRRs sense nucleic acids from microbes and orchestrate cytokine production to resolve infection. Inappropriate recognition of host nucleic acids also results in autoimmune disease. Here we utilize a model of inflammation resulting from accrual of self DNA (DNase II-/- Ifnar-/-) to understand the role of PRR sensing pathways in arthritis and autoantibody production. Using mice deficient in DNase II/Ifnar together with deficiency in either STING or AIM2 (TKO), we reveal central roles for the STING and AIM2 pathway in arthritis. AIM2 TKO mice show limited inflammasome activation and, like STING TKO mice, have reduced inflammation in joints. Surprisingly, autoantibody production is maintained in AIM2 and STING TKO mice, while DNase II-/- Ifnar-/- mice also deficient in Unc93b, a chaperone required for TLR7/9 endosomal localization, fail to produce autoantibodies to nucleic acids. Collectively, these data support distinct roles for cytosolic and endosomal nucleic acid sensing pathways in disease manifestations.
Project description:Colorectal cancer is a leading cause of cancer-related deaths. Mutations in the innate immune receptor AIM2 are frequently identified in patients with colorectal cancer, but how AIM2 modulates colonic tumorigenesis is unknown. Here, we found that Aim2-deficient mice were hypersusceptible to colonic tumor development. Production of inflammasome-associated cytokines and other inflammatory mediators were largely intact in Aim2-deficient mice, however, intestinal stem cells were prone to uncontrolled proliferation. Aberrant Wnt signaling expanded a population of tumor-initiating stem cells in the absence of AIM2. Susceptibility of Aim2-deficient mice to colorectal tumorigenesis was enhanced by a dysbiotic gut microbiota, which was reduced by reciprocal exchange of gut microbiota with wild-type healthy mice. These findings uncover a synergy between a specific host genetic factor and gut microbiota in determining the susceptibility to colorectal cancer. Therapeutic modulation of AIM2 expression and microbiota has the potential to prevent colorectal cancer. We used microarrays to compare the transcriptome Aim2 deficent mice to wild type mice in colon tumor and colitis samples. Here were 12 mice in total, 3 for each genotype and tissue combination.
Project description:Endosomal Toll-like receptors (TLRs) play an important role in the etiology of systemic autoimmune diseases such as SLE, where DNA- and RNA-associated autoantigens activate autoreactive B cells through TLR9- and TLR7-dependent pathways, respectively. Nevertheless, TLR9-deficient autoimmune prone mice develop more severe clinical disease, while TLR7-deficient and TLR7/9-double deficient autoimmune-prone mice develop less severe disease. To determine whether the regulatory activity of TLR9 is B cell intrinsic, we have now directly compared the functional properties of autoantigen activated WT, TLR9-deficient and TLR7-deficient B cells, in an experimental system where proliferation depends on BCR/TLR co-engagement. In vitro, TLR9-deficient cells are less dependent on survival factors for a sustained proliferative response than either WT or TLR7-deficient cells. The TLR9-deficient cells also preferentially differentiate toward the plasma cell lineage, as indicated by expression of CD138, sustained expression of IRF4, and other molecular markers of plasma cells. In vivo, autoantigen-activated TLR9-deficient cells give rise to greater numbers of autoantibody producing cells. Our results identify distinct roles for TLR7 and TLR9 in the differentiation of autoreactive B cells that explain the capacity of TLR9 to limit, and TLR7 to promote, the clinical features of SLE. AM14 WT, Tlr7-/-, Tlr9-/- and Tlr7/9-/- B cells were stimulated with PL2-3 for 0, 6, 24, and 42 hours, for a total of 16 samples.
Project description:Colorectal cancer is a leading cause of cancer-related deaths. Mutations in the innate immune receptor AIM2 are frequently identified in patients with colorectal cancer, but how AIM2 modulates colonic tumorigenesis is unknown. Here, we found that Aim2-deficient mice were hypersusceptible to colonic tumor development. Production of inflammasome-associated cytokines and other inflammatory mediators were largely intact in Aim2-deficient mice, however, intestinal stem cells were prone to uncontrolled proliferation. Aberrant Wnt signaling expanded a population of tumor-initiating stem cells in the absence of AIM2. Susceptibility of Aim2-deficient mice to colorectal tumorigenesis was enhanced by a dysbiotic gut microbiota, which was reduced by reciprocal exchange of gut microbiota with wild-type healthy mice. These findings uncover a synergy between a specific host genetic factor and gut microbiota in determining the susceptibility to colorectal cancer. Therapeutic modulation of AIM2 expression and microbiota has the potential to prevent colorectal cancer.
Project description:Endosomal Toll-like receptors (TLRs) play an important role in the etiology of systemic autoimmune diseases such as SLE, where DNA- and RNA-associated autoantigens activate autoreactive B cells through TLR9- and TLR7-dependent pathways, respectively. Nevertheless, TLR9-deficient autoimmune prone mice develop more severe clinical disease, while TLR7-deficient and TLR7/9-double deficient autoimmune-prone mice develop less severe disease. To determine whether the regulatory activity of TLR9 is B cell intrinsic, we have now directly compared the functional properties of autoantigen activated WT, TLR9-deficient and TLR7-deficient B cells, in an experimental system where proliferation depends on BCR/TLR co-engagement. In vitro, TLR9-deficient cells are less dependent on survival factors for a sustained proliferative response than either WT or TLR7-deficient cells. The TLR9-deficient cells also preferentially differentiate toward the plasma cell lineage, as indicated by expression of CD138, sustained expression of IRF4, and other molecular markers of plasma cells. In vivo, autoantigen-activated TLR9-deficient cells give rise to greater numbers of autoantibody producing cells. Our results identify distinct roles for TLR7 and TLR9 in the differentiation of autoreactive B cells that explain the capacity of TLR9 to limit, and TLR7 to promote, the clinical features of SLE.
Project description:This SuperSeries is composed of the following subset Series: GSE32016: Autoantibody Epitope Spreading in the Pre-Clinical Phase Predicts Progression to Rheumatoid Arthritis [ANALYTE: ANTIGEN] GSE32019: Autoantibody Epitope Spreading in the Pre-Clinical Phase Predicts Progression to Rheumatoid Arthritis [ANALYTE: Cytokine or chemokine] Refer to individual Series
Project description:Cell death plasticity is crucial for modulating tissue homeostasis and immune responses, but our understanding of the molecular components that regulate cell death pathways to determine cell fate remains limited. Here, a CRISPR screen of acute myeloid leukemia cells identifies protein tyrosine phosphatase non-receptor type 23 (PTPN23) as essential for survival. Loss of PTPN23 activates nuclear factor-kappa B, apoptotic, necroptotic, and pyroptotic pathways by causing the accumulation of death receptors and toll-like receptors (TLRs) in endosomes. These effects are recapitulated by depletion of PTPN23 co-dependent genes in the endosomal sorting complex required for transport (ESCRT) pathway. Through proximity-dependent biotin labeling, we show that NAK-associated protein 1 interacts with PTPN23 to facilitate endosomal sorting of tumor necrosis factor receptor 1 (TNFR1), sensitizing cells to TNF-alpha-induced cytotoxicity. Our findings reveal PTPN23-dependent ESCRT machinery as a cell death checkpoint that regulates the spatiotemporal distribution of death receptors and TLRs to restrain multiple cell death pathways.
Project description:The development of oral squamous cell carcinoma (OSCC) is a multistep process requiring the accumulation of genetic alterations. To identify genes responsible for OSCC development, we performed high-density single-nucleotide polymorphism array analysis and genome-wide gene expression profiling on OSCC tumors. These analyses identified "absent in melanoma (AIM2)" and "interferon-inducible gene 16 (IFI16)," mapped to the hematopoietic IFN-inducible nuclear proteins with 200-amino acid repeat (HIN-200) gene cluster in the amplified region of chromosome 1q23, with overexpression in OSCCs. AIM2 and IFI16 are cytoplasmic double-stranded DNA sensors for innate immunity and act as tumor suppressors in several human cancers. Knockdown of AIM2 or IFI16 in OSCC cells resulted in the suppression of cell growth and the induction of apoptosis, accompanied by the downregulation of NF-κB activation. Because all of the OSCC cell lines had impairment of p53 activity, wild-type p53 was introduced in p53-deficient OSCC cells, and as a result, the expression of wild-type p53 suppressed cell growth and induced apoptosis via suppression of NF-κB activity. Finally, the coexpression of AIM2 and IFI16 significantly enhanced cell growth in p53-deficient cells; in contrast, the expression of AIM2 and/or IFI16 in cells bearing wild-type p53 suppressed cell growth. Moreover, AIM2 and IFI16 synergistically enhanced NF-κB signaling in p53-deficient cells. Thus, expression of AIM2 and IFI16 may have oncogenic functions in OSCC cells inactivating p53 system. Copy number analysis of Affymetrix 250K SNP arrays was performed for 5 oral leukoplakia samples, 20 oral squamous cell carcinoma samples, and 8 oral squamous cell carcinoma cell lines.
Project description:The pathogenesis of rheumatoid arthritis (RA) is complicated and involves both innate and adaptive immunity [5]. The innate immunity such as macrophages or fibroblast-like synoviocytes (FLS) in the synovium can generate inflammatory mediators, including TNF-α, IL-1, IL-6, IL-17, IFN-γ, and chemo kines that lead to synovial inflammation, bone erosion, and cartilage damage [6-8]. The IL-17 signaling mediates the autoantibody production in collagen-induced arthritis (CIA) model [9]. However, the treatment response with an anti-IL17 monoclonal antibody in RA patients shows a high degree of heterogeneity [10]. The inhibitors of the Janus kinase (JAK) pathway are approved for RA patients [11]. These data suggest that the targeted multiple cytokines through the JAK pathway are useful for RA treatment. Disturbance of type I IFNs (IFNs-I) signaling and production drive autoimmune development [12]. The presymptomatic RA patients display an increase of IFNs-I before the onset of symptoms [13]. The RA patients also show the elevation of IFN- α in the synovial fluid and high expression of IFNs-I regulated gene in peripheral blood mononuclear cells (PBMC) [14]. However, the role of IFNs-I in arthritis and bone homeostasis has suggested the accelerating effect of arthritis and bone damage. The interferon-alpha receptor knockout mice develop arthritis severity higher than wild-type mice in the model of antigen-induced arthritis [15]. IFNs-I also affects the bone homeostasis by inhibiting osteoclastogenesis via receptor activator of nuclear factor-kappa B (RANK) pathway, and reduction of c-FOS expression [16-18]. Therefore, the goal of RA treatment with antagonizing the IFNs-I pathway has to be optimized between efficacy and potentially adverse effect. STING is a cytosolic DNA sensor that initiates the production of IFNs-I. STING functions have been reported as both pro-inflammatory signaling and negative regulator against inflammation [19-21]. The mutation in exon 5 of the STING gene results in gain function leading to initiate inflammation and cause the Sting associated vasculopathy with onset in infancy (SAVI) [22]. Loss of STING function rescues DNaseII-deficient mice from lethality and polyarthritis [23]. However, Sting-deficient lupus mice (MRL/Lpr mice) show higher and earlier mortality than Sting-sufficient MRL/Lpr mice [24]. The pathology also shows lymphoid hypertrophy with a higher amount of macrophages and granulocytes infiltration, autoantibodies, and cytokine [24]. The objective of this study was to identify the role of STING in the pathogenesis of rheumatoid arthritis using collagen-induced arthritis (CIA) model as a representative model of the human RA.
Project description:[Background] TNFa-induced adipose-related protein (TIARP) is a six-transmembrane protein that is expressed on macrophages, neutrophils and synoviocytes. We have recently reported that TIARP deficient mice (TIARP-/-) spontaneously developed arthritis, and had the high susceptibility to collagen-induced arthritis (CIA) with enhanced interleukin (IL)-6 production. However, the effect of TIARP to neutrophils and fibroblast-like syonoviocytes (FLS) has not been clearly elucidated. [Methods] We analyzed the roles of TIARP in K/BxN serum transfer model using TIARP-/- mice. We characterized the differences of neutrophils between WT and TIARP-/- mice by DNA microarray. Transmigration assays of TIARP-/- neutrophils were performed in vitro and in vivo. FLS were cultured with TNF? and the production of CXCL2 (a specific ligand of CXCR1 and CXCR2) and IL-6 were measured by ELISA. Moreover, TIARP-/- mice transferred with K/BxN serum were treated with anti-IL-6R antibodies. [Results] Arthritis in TIARP-/- mice transferred with K/BxN serum was significantly exacerbated. We identified overexpression of CXCR1 and CXCR2 in TIARP-/- neutrophils by DNA microarray. Neutrophils from TIARP-/- mice showed strong migration activity. The enhancement of chomotactic activity of TIARP-/- neutrophil was greatly facilitated by CXCL2 in vitro and in vivo. In addition, TIARP-/-FLS has enhanced the production of CXCL2 and IL-6 and the cell proliferation in the presence of TNFa, and the blockade of IL-6R significantly attenuated arthritis in vivo. [Conclusion] Our findings indicate that TIARP might down-regulate the production of CXCL2 and IL-6 in FLS, and the expression of chemokine receptors (CXCR1 and CXCR2) in neutrophils, resulting in the protective ability of neutrophils migration into arthritic joints. Mice were treated with thiogycollate medium intraperitoneally. After 3 days, peritoneal macrophages were isolated from three WT or TIARP-deficient mice, and these cells were stimulated by TNF? for 24 hours. Ly6G+ Neutrophils were isolated from splenocytes by MACS.