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Background: Intervertebral disc degeneration (IDD) is widely regarded as the primary contributor to low back pain(LBP). As an immune-privileged organ, upon the onset of IDD, various components of the nucleus pulposus (NP) are exposed to the host’s immune system, accumulating cytokines. Cytokines facilitate intercellular communication within the immune system, induce immune cells polarisation, and exacerbate oxidative stress in IDD. Methods: Machine learning was used to identify crucial immune cells. Subsequently, Immune Response Enrichment Analysis (IREA) was conducted on the key immune cells to determine their cytokine responses and polarisation states in IDD. “CellChat” package facilitated the analysis of cell-cell communication. Differential gene expression analysis, PPI network, GO and KEGG pathway enrichment analysis, GSVA, co-expressed gene analysis and key gene-related networks were also performed to explore hub genes and their associated functions. Lastly, the differential expression and functions of key genes were validated through in vitro and in vivo experiments. Results: Through multiple machine learning methods, monocytes were identified as the crucial immune cells in IDD, exhibiting significant differentiation capacity. IREA revealed that monocytes in IDD polarize into an IFN-a1 and IFN-b enriched Mono-a state, potentially intensifying inflammation. Cell–cell communication analysis uncovered alteration in ANNEXIN pathway and a reduction in CXCL signaling between macrophages and monocytes, suggesting immune response dysregulation. Furthermore, ten algorithms identified three hub genes. Both experiments conducted in vitro and in vivo have conclusively shown that IRF7 serves as a crucial target for the treatment of IDD, and its knockdown alleviates IDD. Eight small-molecule drugs were predicted to have therapeutic potential for IDD. Conclusion: These findings offer a multidimensional understanding of the pathogenesis of IDD, pinpointing monocytes and key genes as potential diagnostic and therapeutic targets. They provide novel insights into potential diagnostic and therapeutic targets for IDD. [ABSTRACT FROM AUTHOR]

Background: The incidence of inflammatory bowel disease (IBD) is on the rise in developing countries, and investigating the underlying mechanisms of IBD is essential for the development of targeted therapeutic interventions. Interferon regulatory factor 7 (IRF7) is known to exert pro-inflammatory effects in various autoimmune diseases, yet its precise role in the development of colitis remains unclear. Methods: We analyzed the clinical significance of IRF7 in ulcerative colitis (UC) by searching RNA-Seq databases and collecting tissue samples from clinical UC patients. And, we performed dextran sodium sulfate (DSS)-induced colitis modeling using WT and Irf7−/− mice to explore the mechanism of IRF7 action on colitis. Results: In this study, we found that IRF7 expression is significantly reduced in patients with UC, and also demonstrated that Irf7−/− mice display heightened susceptibility to DSS-induced colitis, accompanied by elevated levels of colonic and serum pro-inflammatory cytokines, suggesting that IRF7 is able to inhibit colitis. This increased susceptibility is linked to compromised intestinal barrier integrity and impaired expression of key molecules, including Muc2, E-cadherin, β-catenin, Occludin, and Interleukin-28A (IL-28A), a member of type III interferon (IFN-III), but independent of the deficiency of classic type I interferon (IFN-I) and type II interferon (IFN-II). The stimulation of intestinal epithelial cells by recombinant IL-28A augments the expression of Muc2, E-cadherin, β-catenin, and Occludin. The recombinant IL-28A protein in mice counteracts the heightened susceptibility of Irf7−/− mice to colitis induced by DSS, while also elevating the expression of Muc2, E-cadherin, β-catenin, and Occludin, thereby promoting the integrity of the intestinal barrier. Conclusion: These findings underscore the pivotal role of IRF7 in preserving intestinal homeostasis and forestalling the onset of colitis. [ABSTRACT FROM AUTHOR]

Abstract Background The incidence of inflammatory bowel disease (IBD) is on the rise in developing countries, and investigating the underlying mechanisms of IBD is essential for the development of targeted therapeutic interventions. Interferon regulatory factor 7 (IRF7) is known to exert pro-inflammatory effects in various autoimmune diseases, yet its precise role in the development of colitis remains unclear. Methods We analyzed the clinical significance of IRF7 in ulcerative colitis (UC) by searching RNA-Seq databases and collecting tissue samples from clinical UC patients. And, we performed dextran sodium sulfate (DSS)-induced colitis modeling using WT and Irf7 −/− mice to explore the mechanism of IRF7 action on colitis. Results In this study, we found that IRF7 expression is significantly reduced in patients with UC, and also demonstrated that Irf7 −/− mice display heightened susceptibility to DSS-induced colitis, accompanied by elevated levels of colonic and serum pro-inflammatory cytokines, suggesting that IRF7 is able to inhibit colitis. This increased susceptibility is linked to compromised intestinal barrier integrity and impaired expression of key molecules, including Muc2, E-cadherin, β-catenin, Occludin, and Interleukin-28A (IL-28A), a member of type III interferon (IFN-III), but independent of the deficiency of classic type I interferon (IFN-I) and type II interferon (IFN-II). The stimulation of intestinal epithelial cells by recombinant IL-28A augments the expression of Muc2, E-cadherin, β-catenin, and Occludin. The recombinant IL-28A protein in mice counteracts the heightened susceptibility of Irf7 −/− mice to colitis induced by DSS, while also elevating the expression of Muc2, E-cadherin, β-catenin, and Occludin, thereby promoting the integrity of the intestinal barrier. Conclusion These findings underscore the pivotal role of IRF7 in preserving intestinal homeostasis and forestalling the onset of colitis.

[Display omitted] • CFA intraplantar injection caused a significant decrease in the level of spinal IRF7. • IRF7 plays an important role in the regulation of inflammatory pain. • IRF7 regulates the activation of NF-κB pathways in the spinal cord. • IRF7 modulates the expression of inflammatory mediators in the spinal cord. It is known that nerve signals arising from sites of inflammation lead to persistent changes in the spinal cord and contribute to the amplification and persistence of pain. Nevertheless, the underlying mechanisms have not yet been completely elucidated. We identified differentially expressed genes in the lumbar (L4–L6) segment of the spinal cord from complete Freund's adjuvant (CFA) rats compared to control animals via high throughput sequencing. Based on differential gene expression analysis, we selected interferon regulatory factor 7 (IRF7) for follow-up experiments to explore its antinociceptive potential. An animal model of inflammatory pain was induced by intraplantar injection of CFA. We evaluated the effects of adeno-associated viral (AAV)-mediated overexpression of IRF7 in the spinal cord on pain-related behavior after CFA injection. Moreover, the activation of the nuclear factor-κB (NF-κB) and the expression of inflammatory cytokines were investigated to understand the underlying mechanisms related to the contribution of IRF7 to inflammatory pain. CFA intraplantar injection caused a significant decrease in the level of spinal IRF7, which is mainly expressed in the dorsal horn neurons and astrocytes. Moreover, IRF7 overexpression significantly attenuated pain-related behaviors, as well as the activity of NF-κB/p65 and the production of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the spinal cord of CFA rats. Our data indicated that spinal IRF7 plays an important role in the regulation of inflammatory pain. Thus, IRF7 overexpression at the spinal cord level might represent a potential target for the treatment of inflammatory pain. [ABSTRACT FROM AUTHOR]

Aim: The main focus of this study is to explore the molecular mechanism of IRF7 regulation on RPS18 transcription in M1‐type macrophages in pancreatic adenocarcinoma (PAAD) tissue, as well as the transfer of RPS18 by IRF7 via exosomes to PAAD cells and the regulation of ILF3 expression. Methods: By utilising single‐cell RNA sequencing (scRNA‐seq) data and spatial transcriptomics (ST) data from the Gene Expression Omnibus database, we identified distinct cell types with significant expression differences in PAAD tissue. Among these cell types, we identified those closely associated with lipid metabolism. The differentially expressed genes within these cell types were analysed, and target genes relevant to prognosis were identified. Flow cytometry was employed to assess the expression levels of target genes in M1 and M2 macrophages. Cell lines with target gene knockout were constructed using CRISPR/Cas9 editing technology, and cell lines with target gene knockdown and overexpression were established using lentiviral vectors. Additionally, a co‐culture model of exosomes derived from M1 macrophages with PAAD cells was developed. The impact of M1 macrophage‐derived exosomes on the lipid metabolism of PAAD cells in the model was evaluated through metabolomics analysis. The effects of M1 macrophage‐derived exosomes on the viability, proliferation, division, migration and apoptosis of PAAD cells were assessed using MTT assay, flow cytometry, EdU assay, wound healing assay, Transwell assay and TUNEL staining. Furthermore, a mouse PAAD orthotopic implantation model was established, and bioluminescence imaging was utilised to assess the influence of M1 macrophage‐derived exosomes on the intratumoural formation capacity of PAAD cells, as well as measuring tumour weight and volume. The expression of proliferation‐associated proteins in tumour tissues was examined using immunohistochemistry. Results: Through combined analysis of scRNA‐seq and ST technologies, we discovered a close association between M1 macrophages in PAAD samples and lipid metabolism signals, as well as a negative correlation between M1 macrophages and cancer cells. The construction of a prognostic risk score model identified RPS18 and IRF7 as two prognostically relevant genes in M1 macrophages, exhibiting negative and positive correlations, respectively. Mechanistically, it was found that IRF7 in M1 macrophages can inhibit the transcription of RPS18, reducing the transfer of RPS18 to PAAD cells via exosomes, consequently affecting the expression of ILF3 in PAAD cells. IRF7/RPS18 in M1 macrophages can also suppress lipid metabolism, cell viability, proliferation, migration, invasion and intratumoural formation capacity of PAAD cells, while promoting cell apoptosis. Conclusion: Overexpression of IRF7 in M1 macrophages may inhibit RPS18 transcription, reduce the transfer of RPS18 from M1 macrophage‐derived exosomes to PAAD cells, thereby suppressing ILF3 expression in PAAD cells, inhibiting the lipid metabolism pathway, and curtailing the viability, proliferation, migration, invasion of PAAD cells, as well as enhancing cell apoptosis, ultimately inhibiting tumour formation in PAAD cells in vivo. Targeting IRF7/RPS18 in M1 macrophages could represent a promising immunotherapeutic approach for PAAD in the future. [ABSTRACT FROM AUTHOR]

Type I interferons (IFN-I) are pleiotropic factors endowed with multiple activities that play important roles in innate and adaptive immunity. Although many studies indicate that IFN-I inducers exert favorable effects on broad-spectrum antivirus, immunomodulation, and anti-tumor activities by inducing endogenous IFN-I and IFN-stimulated genes, their function in bone homeostasis still needs further exploration. Here, our study demonstrates 2 distinct IFN-I inducers, diABZI and poly(I:C), as potential therapeutics to alleviate osteolysis and osteoporosis. First, IFN-I inducers suppress the genes that control osteoclast (OC) differentiation and activity in vitro. Moreover, diABZI alleviates bone loss in Ti particle-induced osteolysis and ovariectomized -induced osteoporosis in vivo by inhibiting OC differentiation and function. In addition, the inhibitory effects of IFN-I inducers on OC differentiation are not observed in macrophages derived from Ifnar1−/−mice, which indicate that the suppressive effect of IFN-I inducers on OC is IFNAR-dependent. Mechanistically, RNAi-mediated silencing of IRF7 and IFIT3 in OC precursors impairs the suppressive effect of the IFN-I inducers on OC differentiation. Taken together, these results demonstrate that IFN-I inducers play a protective role in bone turnover by limiting osteoclastogenesis and bone resorption through the induction of OC-specific mediators via the IFN-I signaling pathway. Lay Summary: OCs are responsible for bone resorption, and their excessive differentiation and enhanced activity will lead to bone resorption diseases such as osteoporosis and osteolysis. Here, our study demonstrates 2 distinct IFN-I inducers, diABZI and poly(I:C), as potential therapeutics to alleviate osteolysis and osteoporosis. IFN-I inducers suppress OC differentiation, and particularly diABZI alleviates bone loss in osteolysis and osteoporosis mouse models. Taken together, IFN-I inducers play a protective role in bone turnover by limiting osteoclastogenesis and bone resorption through the induction of OC-specific mediators via the IFN-I signaling pathway. Our in-depth and comprehensive discovery of the IFN-I inducer would provide new insight into OC biology and therapeutic targets for osteoclastic bone resorption diseases. Graphical Abstract [ABSTRACT FROM AUTHOR]

Myeloid-derived suppressor cells (MDSCs) play a crucial role in promoting melanoma metastasis. Reprogramming MDSCs into mature M1 macrophages has emerged as a strategy to inhibit metastasis. Decitabine (Dec) is known to eradicate MDSCs and suppress tumor growth. In this study, we provide evidence that Dec not only reduces the MDSC population by inducing apoptosis, arresting cell cycle, and impairing recruitment, but also suppresses their immunosuppressive function by downregulating related genes and facilitating differentiation into M1 macrophages. Transcriptomic analysis of Dec-treated MDSCs revealed a marked downregulation of immunosuppressive genes including S100a9, S100a8, Vegf, Cxcr2, and Nos2. Meanwhile, M1 macrophage-associated genes involved in immune activation were upregulated, such as Ddx58, Isg15, Tap1, Ccl5, Cxcl9, and Cxcl10. Further bioinformatic analysis indicated that Dec promotes MDSC-to-M1 macrophage differentiation and activates innate immune pathways including NOD-like signaling to enhance anti-tumor immunity. Time-course studies implied that Dec upregulates myeloid transcription factor Irf7 to initiate MDSC differentiation and orchestrate the anti-tumor immune response. Collectively, our study unveils a novel dual-functional mechanism of Dec as both a cytotoxic agent reducing MDSCs and an inducer of their differentiation into M1 macrophages, thereby alleviating immunosuppression. This highlights Dec's potential for clinical melanoma metastasis suppression. [ABSTRACT FROM AUTHOR]

Abstract Background Macrophage proinflammatory activation contributes to the pathology of severe acute pancreatitis (SAP) and, simultaneously, macrophage functional changes, and increased pyroptosis/necrosis can further exacerbate the cellular immune suppression during the process of SAP, where cyclic GMP–AMP synthase (cGAS)–stimulator of interferon genes (STING) plays an important role. However, the function and mechanism of cGAS–STING in SAP-induced lung injury (LI) remains unknown. Methods Lipopolysaccharide (LPS) was combined with caerulein-induced SAP in wild type, cGAS −/− and sting −/− mice. Primary macrophages were extracted via bronchoalveolar lavage and peritoneal lavage. Ana-1 cells were pretreated with LPS and stimulated with nigericin sodium salt to induce pyroptosis in vitro. Results SAP triggered NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation-mediated pyroptosis of alveolar and peritoneal macrophages in mouse model. Knockout of cGAS/STING could ameliorate NLRP3 activation and macrophage pyroptosis. In addition, mitochondrial (mt)DNA released from damaged mitochondria further induced macrophage STING activation in a cGAS- and dose-dependent manner. Upregulated STING signal can promote NLRP3 inflammasome-mediated macrophage pyroptosis and increase serum interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α levels and, thus, exacerbate SAP-associated LI (SAP-ALI). Downstream molecules of STING, IRF7, and IRF3 connect the mtDNA–cGAS–STING axis and the NLRP3–pyroptosis axis. Conclusions Negative regulation of any molecule in the mtDNA–cGAS–STING–IRF7/IRF3 pathway can affect the activation of NLRP3 inflammasomes, thereby reducing macrophage pyroptosis and improving SAP-ALI in mouse model.

Background: Macrophage proinflammatory activation contributes to the pathology of severe acute pancreatitis (SAP) and, simultaneously, macrophage functional changes, and increased pyroptosis/necrosis can further exacerbate the cellular immune suppression during the process of SAP, where cyclic GMP–AMP synthase (cGAS)–stimulator of interferon genes (STING) plays an important role. However, the function and mechanism of cGAS–STING in SAP-induced lung injury (LI) remains unknown. Methods: Lipopolysaccharide (LPS) was combined with caerulein-induced SAP in wild type, cGAS −/− and sting −/− mice. Primary macrophages were extracted via bronchoalveolar lavage and peritoneal lavage. Ana-1 cells were pretreated with LPS and stimulated with nigericin sodium salt to induce pyroptosis in vitro. Results: SAP triggered NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation-mediated pyroptosis of alveolar and peritoneal macrophages in mouse model. Knockout of cGAS/STING could ameliorate NLRP3 activation and macrophage pyroptosis. In addition, mitochondrial (mt)DNA released from damaged mitochondria further induced macrophage STING activation in a cGAS- and dose-dependent manner. Upregulated STING signal can promote NLRP3 inflammasome-mediated macrophage pyroptosis and increase serum interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α levels and, thus, exacerbate SAP-associated LI (SAP-ALI). Downstream molecules of STING, IRF7, and IRF3 connect the mtDNA–cGAS–STING axis and the NLRP3–pyroptosis axis. Conclusions: Negative regulation of any molecule in the mtDNA–cGAS–STING–IRF7/IRF3 pathway can affect the activation of NLRP3 inflammasomes, thereby reducing macrophage pyroptosis and improving SAP-ALI in mouse model. [ABSTRACT FROM AUTHOR]

Radiotherapy (RT) can induce tumor regression outside the irradiation field, known as the abscopal effect. However, the detailed underlying mechanisms remain largely unknown. A tumor‐bearing mouse model is successfully constructed by inducing both subcutaneous tumors and lung metastases. Single‐cell RNA sequencing, immunofluorescence, and flow cytometry are performed to explore the regulation of tumor microenvironment (TME) by RT. A series of in vitro assays, including luciferase reporter, RNA Pulldown, and fluorescent in situ hybridization (FISH) assays, are performed to evaluate the detailed mechanism of the abscopal effect. In addition, in vivo assays are performed to investigate combination therapy strategies for enhancing the abscopal effect. The results showed that RT significantly inhibited localized tumor and lung metastasis progression and improved the TME. Mechanistically, RT promoted the release of tumor‐derived exosomes carrying circPIK3R3, which is taken up by macrophages. circPIK3R3 promoted Type I interferon (I‐IFN) secretion and M1 polarization via the miR‐872‐3p/IRF7 axis. Secreted I‐IFN activated the JAK/STAT signaling pathway in CD8+ T cells, and promoted IFN‐γ and GZMB secretion. Together, the study shows that tumor‐derived exosomes promote I‐IFN secretion via the circPIK3R3/miR‐872‐3p/IRF7 axis in macrophages and enhance the anti‐tumor immune response of CD8+ T cells. [ABSTRACT FROM AUTHOR]

p53 is mutated in half of cancer cases. However, no p53-targeting drugs have been approved. Here, we reposition decitabine for triple-negative breast cancer (TNBC), a subtype with frequent p53 mutations and extremely poor prognosis. In a retrospective study on tissue microarrays with 132 TNBC cases, DNMT1 overexpression was associated with p53 mutations (P = 0.037) and poor overall survival (OS) (P = 0.010). In a prospective DEciTabinE and Carboplatin in TNBC (DETECT) trial (NCT03295552), decitabine with carboplatin produced an objective response rate (ORR) of 42% in 12 patients with stage IV TNBC. Among the 9 trialed patients with available TP53 sequencing results, the 6 patients with p53 mutations had higher ORR (3/6 vs. 0/3) and better OS (16.0 vs. 4.0 months) than the patients with wild-type p53. In a mechanistic study, isogenic TNBC cell lines harboring DETECT-derived p53 mutations exhibited higher DNMT1 expression and decitabine sensitivity than the cell line with wild-type p53. In the DETECT trial, decitabine induced strong immune responses featuring the striking upregulation of the innate immune player IRF7 in the p53-mutated TNBC cell line (upregulation by 16-fold) and the most responsive patient with TNBC. Our integrative studies reveal the potential of repurposing decitabine for the treatment of p53-mutated TNBC and suggest IRF7 as a potential biomarker for decitabine-based treatments. [ABSTRACT FROM AUTHOR]

Abstract Aim The main focus of this study is to explore the molecular mechanism of IRF7 regulation on RPS18 transcription in M1‐type macrophages in pancreatic adenocarcinoma (PAAD) tissue, as well as the transfer of RPS18 by IRF7 via exosomes to PAAD cells and the regulation of ILF3 expression. Methods By utilising single‐cell RNA sequencing (scRNA‐seq) data and spatial transcriptomics (ST) data from the Gene Expression Omnibus database, we identified distinct cell types with significant expression differences in PAAD tissue. Among these cell types, we identified those closely associated with lipid metabolism. The differentially expressed genes within these cell types were analysed, and target genes relevant to prognosis were identified. Flow cytometry was employed to assess the expression levels of target genes in M1 and M2 macrophages. Cell lines with target gene knockout were constructed using CRISPR/Cas9 editing technology, and cell lines with target gene knockdown and overexpression were established using lentiviral vectors. Additionally, a co‐culture model of exosomes derived from M1 macrophages with PAAD cells was developed. The impact of M1 macrophage‐derived exosomes on the lipid metabolism of PAAD cells in the model was evaluated through metabolomics analysis. The effects of M1 macrophage‐derived exosomes on the viability, proliferation, division, migration and apoptosis of PAAD cells were assessed using MTT assay, flow cytometry, EdU assay, wound healing assay, Transwell assay and TUNEL staining. Furthermore, a mouse PAAD orthotopic implantation model was established, and bioluminescence imaging was utilised to assess the influence of M1 macrophage‐derived exosomes on the intratumoural formation capacity of PAAD cells, as well as measuring tumour weight and volume. The expression of proliferation‐associated proteins in tumour tissues was examined using immunohistochemistry. Results Through combined analysis of scRNA‐seq and ST technologies, we discovered a close association between M1 macrophages in PAAD samples and lipid metabolism signals, as well as a negative correlation between M1 macrophages and cancer cells. The construction of a prognostic risk score model identified RPS18 and IRF7 as two prognostically relevant genes in M1 macrophages, exhibiting negative and positive correlations, respectively. Mechanistically, it was found that IRF7 in M1 macrophages can inhibit the transcription of RPS18, reducing the transfer of RPS18 to PAAD cells via exosomes, consequently affecting the expression of ILF3 in PAAD cells. IRF7/RPS18 in M1 macrophages can also suppress lipid metabolism, cell viability, proliferation, migration, invasion and intratumoural formation capacity of PAAD cells, while promoting cell apoptosis. Conclusion Overexpression of IRF7 in M1 macrophages may inhibit RPS18 transcription, reduce the transfer of RPS18 from M1 macrophage‐derived exosomes to PAAD cells, thereby suppressing ILF3 expression in PAAD cells, inhibiting the lipid metabolism pathway, and curtailing the viability, proliferation, migration, invasion of PAAD cells, as well as enhancing cell apoptosis, ultimately inhibiting tumour formation in PAAD cells in vivo. Targeting IRF7/RPS18 in M1 macrophages could represent a promising immunotherapeutic approach for PAAD in the future.

Toll-like receptors (TLRs) are a family of innate immune receptors that recognize molecular patterns in foreign pathogens and intrinsic danger/damage signals from cells. TLR7 is a nucleic acid sensing endosomal TLR that is activated by single-stranded RNAs from microbes or by small noncoding RNAs that act as endogenous ligands. TLR7 signals through the MyD88 adaptor protein and activates the transcription factor interferon regulatory factor 7 (IRF7). TLR7 is found throughout the brain and is highly expressed in microglia, the main immune cells of the brain that have also been implicated in alcohol drinking in mice. Upregulation of TLR7 mRNA and protein has been identified in postmortem hippocampus and cortex from AUD subjects that correlated positively with lifetime consumption of alcohol. Similarly, Tlr7 and downstream signaling genes were upregulated in rat hippocampal and cortical slice cultures after chronic alcohol exposure and in these regions after chronic binge-like alcohol treatment in mice. In addition, repeated administration of the synthetic TLR7 agonists imiquimod (R837) or resiquimod (R848) increased voluntary alcohol drinking in different rodent models and produced sustained upregulation of IRF7 in the brain. These findings suggest that chronic TLR7 activation may drive excessive alcohol drinking. In the brain, this could occur through increased levels of endogenous TLR7 activators, like microRNAs and Y RNAs. This review explores chronic TLR7 activation as a pathway of dysregulated neuroimmune signaling in AUD and the endogenous small RNA ligands in the brain that could perpetuate innate immune responses and escalate alcohol drinking.

Background & aimsThe stimulator of interferon genes (STING)/TANK-binding kinase 1 (TBK1) pathway is vital in mediating innate immune and inflammatory responses during oxidative/endoplasmic reticulum (ER) stress. However, it remains unknown whether macrophage thioredoxin-interacting protein (TXNIP) may regulate TBK1 function and cell death pathways during oxidative/ER stress.MethodsA mouse model of hepatic ischaemia/reperfusion injury (IRI), the primary hepatocytes, and bone marrow-derived macrophages were used in the myeloid-specific TXNIP knockout (TXNIPM-KO) and TXNIP-proficient (TXNIPFL/FL) mice.ResultsThe TXNIPM-KO mice were resistant to ischaemia/reperfusion (IR) stress-induced liver damage with reduced serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) levels, macrophage/neutrophil infiltration, and pro-inflammatory mediators compared with the TXNIPFL/FL controls. IR stress increased TXNIP, p-STING, and p-TBK1 expression in ischaemic livers. However, TXNIPM-KO inhibited STING, TBK1, interferon regulatory factor 3 (IRF3), and NF-κB activation with interferon-β (IFN-β) expression. Interestingly, TXNIPM-KO augmented nuclear factor (erythroid-derived 2)-like 2 (NRF2) activity, increased antioxidant gene expression, and reduced macrophage reactive oxygen species (ROS) production and hepatic apoptosis/necroptosis in IR-stressed livers. Mechanistically, macrophage TXNIP deficiency promoted cylindromatosis (CYLD), which colocalised and interacted with NADPH oxidase 4 (NOX4) to enhance NRF2 activity by deubiquitinating NOX4. Disruption of macrophage NRF2 or its target gene 2',5' oligoadenylate synthetase-like 1 (OASL1) enhanced Ras GTPase-activating protein-binding protein 1 (G3BP1) and TBK1-mediated inflammatory response. Notably, macrophage OASL1 deficiency induced hepatocyte apoptotic peptidase activating factor 1 (APAF1), cytochrome c, and caspase-9 activation, leading to increased caspase-3-initiated apoptosis and receptor-interacting serine/threonine-protein kinase 3 (RIPK3)-mediated necroptosis.ConclusionsMacrophage TXNIP deficiency enhances CYLD activity and activates the NRF2-OASL1 signalling, controlling IR stress-induced liver injury. The target gene OASL1 regulated by NRF2 is crucial for modulating STING-mediated TBK1 activation and Apaf1/cytochrome c/caspase-9-triggered apoptotic/necroptotic cell death pathway. Our findings underscore a novel role of macrophage TXNIP-mediated CYLD-NRF2-OASL1 axis in stress-induced liver inflammation and cell death, implying the potential therapeutic targets in liver inflammatory diseases.Lay summaryLiver inflammation and injury induced by ischaemia and reperfusion (the absence of blood flow to the liver tissue followed by the resupply of blood) is a significant cause of hepatic dysfunction and failure following liver transplantation, resection, and haemorrhagic shock. Herein, we uncover an underlying mechanism that contributes to liver inflammation and cell death in this setting and could be a therapeutic target in stress-induced liver inflammatory injury.

In the realm of Parkinson's disease (PD) research, NLRP3 inflammasome-mediated pyroptosis has recently garnered significant attention as a potential novel form of dopaminergic neuronal death. Our previous research revealed the activation of innate immune-related genes, such as the TLR4 signaling pathway and interferon regulatory factor 7 (IRF7), although the specific mechanism remains unclear. Our current study shed light on whether the TLR4 signaling pathway and IRF7 can affect the pyroptosis of dopaminergic nerve cells and thus participate in the pathogenesis of PD. The PD model was constructed by MPP+ treatment of PC12 cells or stereotactic injection of the striatum of SD rats, and the expression of genes were detected by RT-qPCR and Western Blotting. Lentivirus, siRNA and (5Z)-7-Oxozeaenol were used to validate the regulation of this pathway on pyroptosis. The expression of TLR4, TAK1, IRF7 and pyroptosis molecular markers was upregulated after MPP+ treatment. IRF7 could affect dopaminergic neural cells pyroptosis by targeted regulation of NLRP3. Furthermore, inhibition of the TLR4/TAK1 signaling pathway led to a decrease in the expression of both IRF7 and NLRP3, while overexpression of IRF7 reversed the reduction in pyroptosis and increase in TH expression. TLR4/TAK1/IRF7 axis can promote PD by influencing pyroptosis through NLRP3. [ABSTRACT FROM AUTHOR]

Background: The production of interferons (IFNs) is essential for the control of viral infections, and interferon regulatory factor 7 (IRF7) is considered as a vital regulator for the transcription of type I IFNs. Amphibians appear to possess a highly expanded type I IFN repertoire, consisting of intron-containing genes as observed in fish, and intronless genes as in other higher vertebrates. However, the knowledge on transcriptional regulatory mechanism of these two types of type I IFN genes is rather scarce in amphibians. Methods and results: A IRF7 gene named as Np-IRF7 was identified in Tibetan frog (Nanorana parkeri), and bioinformatic analysis revealed that the predicted protein of Np-IRF7 contains several important structural features known in IRF7. Expression analysis showed that Np-IRF7 gene was widely expressed and rapidly induced by poly(I:C) in different organs/tissues. Interestingly, luciferase reporter assay revealed that intronless IFN promoters were more effectively activated than intron-containing IFN promoter in Np-IRF7-transfected cells. Moreover, the overexpression of Np-IRF7 could induce the expression of ISGs and suppress the replication of FV3 in A6 cells. Conclusion: Np-IRF7 is indeed the ortholog of known IRF7, and IRF7 is structurally conserved in different lineages of vertebrates. Np-IRF7 played distinct roles in the activation of intron-containing and intronless type I IFN promoters, thus inducing the expression of interferon-stimulated antiviral effectors and providing a protection against ranavirus infection. The present research thus contributes to a better understanding of regulatory function of IRF7 in the IFN-mediated antiviral response of anuran amphibians. [ABSTRACT FROM AUTHOR]

Abstract Radiotherapy (RT) can induce tumor regression outside the irradiation field, known as the abscopal effect. However, the detailed underlying mechanisms remain largely unknown. A tumor‐bearing mouse model is successfully constructed by inducing both subcutaneous tumors and lung metastases. Single‐cell RNA sequencing, immunofluorescence, and flow cytometry are performed to explore the regulation of tumor microenvironment (TME) by RT. A series of in vitro assays, including luciferase reporter, RNA Pulldown, and fluorescent in situ hybridization (FISH) assays, are performed to evaluate the detailed mechanism of the abscopal effect. In addition, in vivo assays are performed to investigate combination therapy strategies for enhancing the abscopal effect. The results showed that RT significantly inhibited localized tumor and lung metastasis progression and improved the TME. Mechanistically, RT promoted the release of tumor‐derived exosomes carrying circPIK3R3, which is taken up by macrophages. circPIK3R3 promoted Type I interferon (I‐IFN) secretion and M1 polarization via the miR‐872‐3p/IRF7 axis. Secreted I‐IFN activated the JAK/STAT signaling pathway in CD8+ T cells, and promoted IFN‐γ and GZMB secretion. Together, the study shows that tumor‐derived exosomes promote I‐IFN secretion via the circPIK3R3/miR‐872‐3p/IRF7 axis in macrophages and enhance the anti‐tumor immune response of CD8+ T cells.

Abstract Objective To investigate the mechanism of action of Srg3 in acute lung injury caused by sepsis. Methods First, a sepsis-induced acute lung injury rat model was established using cecal ligation and puncture (CLP). RNA sequencing (RNA-seq) was used to screen for highly expressed genes in sepsis-induced acute lung injury (ALI), and the results showed that Srg3 was significantly upregulated. Then, SWI3-related gene 3 (Srg3) was knocked down using AAV9 vector in vivo, and changes in ALI symptoms in rats were analyzed. In vitro experiments were conducted by establishing a cell model using lipopolysaccharide (LPS)-induced BEAS-2B cells and coculturing them with phorbol 12-myristate 13-acetate (PMA)-treated THP-1 cells to analyze macrophage polarization. Next, downstream signaling pathways regulated by Srg3 and transcription factors involved in regulating Srg3 expression were analyzed using the KEGG database. Finally, gain-of-loss functional validation experiments were performed to analyze the role of downstream signaling pathways regulated by Srg3 and transcription factors involved in regulating Srg3 expression in sepsis-induced acute lung injury. Results Srg3 was significantly upregulated in sepsis-induced acute lung injury, and knocking down Srg3 significantly improved the symptoms of ALI in rats. Furthermore, in vitro experiments showed that knocking down Srg3 significantly weakened the inhibitory effect of LPS on the viability of BEAS-2B cells and promoted alternative activation phenotype (M2) macrophage polarization. Subsequent experiments showed that Srg3 can regulate the activation of the NF-κB signaling pathway and promote ferroptosis. Specific activation of the NF-κB signaling pathway or ferroptosis significantly weakened the effect of Srg3 knockdown. It was then found that Srg3 can be transcriptionally activated by interferon regulatory factor 7 (Irf7), and specific inhibition of Irf7 significantly improved the symptoms of ALI. Conclusions Irf7 transcriptionally activates the expression of Srg3, which can promote ferroptosis and activate classical activation phenotype (M1) macrophage polarization by regulating the NF-κB signaling pathway, thereby exacerbating the symptoms of septic lung injury.

Abstract Background Type I interferons (IFN-I) are fundamental in controlling viral infections but fatal interferonopathy is restricted in the immune-privileged central nervous system (CNS). In contrast to the well-established role of Interferon Regulatory Factor 7 (IRF7) in the regulation of IFN-I response in the periphery, little is known about the specific function in the CNS. Methods To investigate the role for IRF7 in antiviral response during neurotropic virus infection, mice deficient for IRF3 and IRF7 were infected systemically with Langat virus (LGTV). Viral burden and IFN-I response was analyzed in the periphery and the CNS by focus formation assay, RT-PCR, immunohistochemistry and in vivo imaging. Microglia and infiltration of CNS-infiltration of immune cells were characterized by flow cytometry. Results Here, we demonstrate that during infection with the neurotropic Langat virus (LGTV), an attenuated member of the tick-borne encephalitis virus (TBEV) subgroup, neurons do not rely on IRF7 for cell-intrinsic antiviral resistance and IFN-I induction. An increased viral replication in IRF7-deficient mice suggests an indirect antiviral mechanism. Astrocytes rely on IRF7 to establish a cell-autonomous antiviral response. Notably, the loss of IRF7 particularly in astrocytes resulted in a high IFN-I production. Sustained production of IFN-I in astrocytes is independent of an IRF7-mediated positive feedback loop. Conclusion IFN-I induction in the CNS is profoundly regulated in a cell type-specific fashion.

Background: Retinal pigment epithelial (RPE) cells have a pivotal function in preserving the equilibrium of the retina and moderating the immunological interaction between the choroid and the retina. This study primarily focuses on delineating the protective effect offered by Kaempferol (Kae) against RPE cell damage. Methods: Bioinformatics analysis was performed on the GSE30719 dataset to identify hub genes associated with RPE. Subsequently, we analyzed the impact of Kae on RPE apoptosis, cell viability, and inflammatory response through cell experiments, and explored the interaction between hub genes and Kae. Results: Based on the GSE30719 dataset, nine hub genes (ISG15, IFIT1, IFIT3, STAT1, OASL, RSAD2, IRF7, MX2, and MX1) were identified, all of which were highly expressed in the GSE30719 case group. Kae could boost the proliferative activity of RPE cells caused by lipopolysaccharide (LPS), as well as reduce apoptosis and the generation of inflammatory factors (tumor necrosis factor receptor (TNFR), interleukin-1beta (IL-1β)) and cytokines (IL-1, IL-6, IL-12). STAT1 was shown to inhibit cell proliferation, promote apoptosis, and secrete IL-1/IL-6/IL-12 in LPS-induced RPE cells. Moreover, IRF7 was found to interact with STAT1 in LPS-induced RPE cells, and STAT1 could maintain IRF7 levels through deubiquitination. In addition, we also found that the protective effect of Kae on LPS-induced RPE cell injury was mediated through STAT1/IRF7 axis. Conclusion: This study provided evidence that Kae protects RPE cells via regulating the STAT1/IRF7 signaling pathways, indicating its potential therapeutic relevance in the diagnosis and management of retinal disorders linked with RPE cell damage.

1,2-Dichloroethane (1,2-DCE) is a prevalent environmental contaminant, and our study revealed its induction of testicular toxicity in mice upon subacute exposure. Melatonin, a prominent secretory product of the pineal gland, has been shown to offer protection against pyroptosis in male reproductive toxicity. However, the exact mechanism underlying 1,2-DCE-induced testicular toxicity and the comprehensive extent of melatonin's protective effects in this regard remain largely unexplored. Therefore, we sequenced testis piRNAs in mice exposed to environmentally relevant concentrations of 1,2-DCE by 28-day dynamic inhalation, and investigated the role of key piRNAs using GC-2 spd cells. Our results showed that 1,2-DCE induced mouse testicular damage and GC-2 spd cell pyroptosis. 1,2-DCE upregulated the expression of pyroptosis-correlated proteins in both mouse testes and GC-2 spd cells. 1,2-DCE exposure caused pore formation on cellular membranes and lactate dehydrogenase leakage in GC-2 spd cells. Additionally, we identified three upregulated piRNAs in 1,2-DCE-exposed mouse testes, among which piR-mmu-1019957 induced pyroptosis in GC-2 spd cells, and its inhibition alleviated 1,2-DCE-induced pyroptosis. PiR-mmu-1019957 mimic and 1,2-DCE treatment activated the expression of interferon regulatory factor 7 (IRF7) in GC-2 spd cells. IRF7 knockdown reversed 1,2-DCE-induced cellular pyroptosis, and overexpression of piR-mmu-1019957 did not promote pyroptosis when IRF7 was inhibited. Notably, melatonin reversed 1,2-DCE-caused testicular toxicity, cellular pyroptosis, and upregulated piR-mmu-1019957 and IRF7. Collectively, our findings indicated that melatonin mitigates this effect, suggesting its potential as a therapeutic intervention against 1,2-DCE-induced male reproductive toxicity in clinical practice.

ABSTRACTAmong cancer immunotherapy, which has received great attention in recent years, cancer vaccines can potentially prevent recurrent tumors by using the exquisite power and specificity of the immune system. Specifically, whole tumor cell vaccines (WTCVs) based on surgically resected tumors have been considered to elicit robust anti-tumor immune responses by exposing various tumor-associated antigens to host immunity. However, most tumors have little immunogenicity because of immunoediting by continuous interactions with host immunity; thus, preparing WTCVs based on patient-derived non-modified tumors cannot prevent tumor onset. Hence, the immunogenicity of tumor cells must be improved for effective WTCVs. In this study, we indicate the importance of the interferon regulatory factor 7 (Irf7) axis, including Irf7 and its downstream factors, within tumor cells in regulating immunogenicity. Indeed, WTCVs that augmented the Irf7 axis have exerted remarkable recurrence-preventive effects when vaccinated after tumor inactivation by radiation. Most notably, vaccination with murine colon cancer cells that enhanced the Irf7 axis prevented the development of challenged tumors in all mice and resulted in a 100% survival rate during the observation period. Furthermore, the mechanism leading to vaccine effectiveness was mediated by interferon-gamma-producing B cells. This study provides novel insights into how to enhance tumor immunogenicity and use WTCVs as recurrence prophylaxis.

Objective: To investigate the mechanism of action of Srg3 in acute lung injury caused by sepsis. Methods: First, a sepsis-induced acute lung injury rat model was established using cecal ligation and puncture (CLP). RNA sequencing (RNA-seq) was used to screen for highly expressed genes in sepsis-induced acute lung injury (ALI), and the results showed that Srg3 was significantly upregulated. Then, SWI3-related gene 3 (Srg3) was knocked down using AAV9 vector in vivo, and changes in ALI symptoms in rats were analyzed. In vitro experiments were conducted by establishing a cell model using lipopolysaccharide (LPS)-induced BEAS-2B cells and coculturing them with phorbol 12-myristate 13-acetate (PMA)-treated THP-1 cells to analyze macrophage polarization. Next, downstream signaling pathways regulated by Srg3 and transcription factors involved in regulating Srg3 expression were analyzed using the KEGG database. Finally, gain-of-loss functional validation experiments were performed to analyze the role of downstream signaling pathways regulated by Srg3 and transcription factors involved in regulating Srg3 expression in sepsis-induced acute lung injury. Results: Srg3 was significantly upregulated in sepsis-induced acute lung injury, and knocking down Srg3 significantly improved the symptoms of ALI in rats. Furthermore, in vitro experiments showed that knocking down Srg3 significantly weakened the inhibitory effect of LPS on the viability of BEAS-2B cells and promoted alternative activation phenotype (M2) macrophage polarization. Subsequent experiments showed that Srg3 can regulate the activation of the NF-κB signaling pathway and promote ferroptosis. Specific activation of the NF-κB signaling pathway or ferroptosis significantly weakened the effect of Srg3 knockdown. It was then found that Srg3 can be transcriptionally activated by interferon regulatory factor 7 (Irf7), and specific inhibition of Irf7 significantly improved the symptoms of ALI. Conclusions: Irf7 transcriptionally activates the expression of Srg3, which can promote ferroptosis and activate classical activation phenotype (M1) macrophage polarization by regulating the NF-κB signaling pathway, thereby exacerbating the symptoms of septic lung injury. Highlights: Srg3 is highly expressed in sepsis-induced acute lung injury. Knockdown of Srg3 suppresses lung injury symptoms in septic rats. Srg3 regulates NF-κB signaling pathway and ferroptosis. Irf7 transcriptionally regulates Srg3 and activates its transcriptional activity in sepsis-induced acute lung injury. The overexpression of Irf7 weakens the beneficial effect of Srg3 knockdown on improving sepsis-induced acute lung injury. [ABSTRACT FROM AUTHOR]

The pandemic coronavirus disease 2019 (COVID-19) has caused a high mortality rate and poses a significant threat to the population. The disease may progress with mild symptoms or may cause the need for intensive care, depending on many factors. In this study, it was aimed to determine if there is a tendency due to genetic factors in COVID-19 patients. Ninety-four of 188 patients with mild clinical and 94 with severe clinical symptoms were included in the study. The targeted panel including coagulopathy (F2, F5), viral invasion (ACE2), and inflammation (CXCL8, IFNAR2, IFNL4, IL10, IL2, IL6, IRF7, TLR3, TLR7, TNF) related genes was performed sequenced by the next generation sequencing (NGS). The variants found were classified and univariate analyses were performed to select candidate variables for logistic model. Risk factors and variants were compared. It was revealed that the presence of 2 or more risk factors caused the disease to progress severely (p < 0.001). Heterozygous IRF7:c.1357−23dup variant had a 2.5 times higher risk for mild disease compared to severe disease. Other variants were found to be more significant in mild disease. Since polymorphic variants were not evaluated in the literature, the findings of our study could not be compared with the literature. However, as variants that may be effective in the severity of infections may differ according to ethnicity. This study has the feature of being a guide for subsequent studies to be carried out especially in Turkish population. Clinical course of the COVID-19 is likely to depend on a variety of risk factors, including age, sex, clinical status, immunology and genetic factors. [ABSTRACT FROM AUTHOR]

The pathogenesis of avian leukosis virus subgroup J (ALV-J) is complex and our understanding of it is limited. Based on our previous research, we explored the relationship between ALV-J infection and regulatory factor 1&7 (IRF1 and IRF7), interferon beta (IFNβ), and the newly identified long noncoding RNA IRF1 (LncIRF1). LncIRF1 is 1603 nt and exists in the cytoplasm and nucleus. After the occurrence of ALV-J infection, the expression levels of LncIRF1, IRF1, IRF7, and IFNβ varied in different chicken tissues. In DF1 cell lines of chicken embryo fibroblast cells (DF1 cells) the expression levels of LncIRF1, IRF7, IRF1, and IFNβ increased when ALV-J infection. Similarly, after LncIRF1 overexpression and the ALV-J challenge, the expression levels of IRF1, IRF7, and IFNβ increased, while increased LncIRF1 inhibited the proliferation of DF1 cells. Interference with LncIRF1 did not affect IRF1, IRF7, and IFNβ. However, expression levels of IRF1, IRF7, and IFNβ decreased due to LncIRF1 interference after the ALV-J challenge. An assay of the RNA-binding domain abundant in apicomplexans indicated that most of the proteins bound to LncIRF1 are related to cell proliferation and viral replication and these proteins also interact with IRF1, IRF7, and IFNβ. We suggest that LncIRF1 plays an important immunomodulatory role in the anti-ALV-J response. [ABSTRACT FROM AUTHOR]

Introduction: COVID-19 has been a major focus of scientific research since early 2020. Due to its societal, economic, and clinical impact worldwide, research efforts aimed, among other questions, to address the effect of host genetics in susceptibility and severity of COVID-19. Methods: We, therefore, performed next-generation sequencing of coding and regulatory regions of 16 human genes, involved in maintenance of the immune system or encoding receptors for viral entry into the host cells, in a subset of 60 COVID-19 patients from the General Hospital Tešanj, Bosnia and Herzegovina, classified into three groups of clinical conditions of different severity (“mild,” “moderate,” and “severe”). Results: We confirmed that the male sex and older age are risk factors for severe clinical picture and identified 13 variants on seven genes (CD55, IL1B, IL4, IRF7, DDX58, TMPRSS2, and ACE2) with potential functional significance, either as genetic markers of modulated susceptibility to SARS-CoV-2 infection or modifiers of the infection severity. Our results include variants reported for the first time as potentially associated with COVID-19, but further research and larger patient cohorts are required to confirm their effect. Discussion: Such studies, focused on candidate genes and/or variants, have a potential to answer the questions regarding the effect of human genetic makeup on the expected infection outcome. In addition, loci we identified here were previously reported to have clinical significance in other diseases and viral infections, thus confirming a general, broader significance of COVID-19- related research results following the end of the pandemic period. [ABSTRACT FROM AUTHOR]

Central nervous system (CNS) infection with Sindbis virus (SINV), the prototypic alphavirus, results in encephalomyelitis in a well-established mouse model that is used to characterize immune factors important in controlling viral infection in neurons. We have previously shown that interferon regulatory factor (IRF) 7 is required for survival from SINV encephalomyelitis, as mice deficient in IRF7 (Irf7−/− ) develop paralysis and fatal disease within 7–8 days after infection without clearing infectious virus from the CNS. To determine the contributions of this innate immune factor in the prevention of fatal disease, we characterized the antiviral immune response to SINV infection in Irf7−/− and C57BL/6J [wild-type (WT)] mice. Irf7−/− mice had prolonged and widespread viral infection in motor neuron-rich regions of the CNS associated with more rapid and severe immunopathology in these regions. Proportions of CD8+ T cells and inflammatory macrophages were higher in Irf7−/− mice following infection, but T cells infiltrating the CNS produced fewer antiviral cytokines than in WT mice. Levels of IFN-γ and SINV-specific antibody in motor neuron-rich regions of the brain were comparable or higher than WT, indicating that IRF7 deficiency does not impair expression of these immune factors important in facilitating viral clearance. Therefore, IRF7 is required for the clearance of SINV from motor neuron-rich regions of the CNS through a mechanism that either is necessary for the neuronal response to currently identified mediators of infectious virus clearance or enables the production of additional antiviral factor(s) needed for clearance. IMPORTANCE Viral encephalomyelitis outcome is dependent on host responses to neuronal infection. Interferon (IFN) is an important component of the innate response, and IFN regulatory factor (IRF) 7 is an inducible transcription factor for the synthesis of IFN-α. IRF7-deficient mice develop fatal paralysis after CNS infection with Sindbis virus, while wild-type mice recover. Irf7−/− mice produce low levels of IFN-α but high levels of IFN-β with induction of IFN-stimulated genes, so the reason for this difference is not understood. The current study shows that Irf7−/− mice developed inflammation earlier but failed to clear virus from motor neuron-rich regions of the brainstem and spinal cord. Levels of IFN-γ and virus-specific antibody were comparable, indicating that IRF7 deficiency does not impair expression of these known viral clearance factors. Therefore, IRF7 is either necessary for the neuronal response to currently identified mediators of clearance or enables the production of additional antiviral factor(s) needed for clearance. [ABSTRACT FROM AUTHOR]

Background: Type I interferons (IFN-I) are fundamental in controlling viral infections but fatal interferonopathy is restricted in the immune-privileged central nervous system (CNS). In contrast to the well-established role of Interferon Regulatory Factor 7 (IRF7) in the regulation of IFN-I response in the periphery, little is known about the specific function in the CNS. Methods: To investigate the role for IRF7 in antiviral response during neurotropic virus infection, mice deficient for IRF3 and IRF7 were infected systemically with Langat virus (LGTV). Viral burden and IFN-I response was analyzed in the periphery and the CNS by focus formation assay, RT-PCR, immunohistochemistry and in vivo imaging. Microglia and infiltration of CNS-infiltration of immune cells were characterized by flow cytometry. Results: Here, we demonstrate that during infection with the neurotropic Langat virus (LGTV), an attenuated member of the tick-borne encephalitis virus (TBEV) subgroup, neurons do not rely on IRF7 for cell-intrinsic antiviral resistance and IFN-I induction. An increased viral replication in IRF7-deficient mice suggests an indirect antiviral mechanism. Astrocytes rely on IRF7 to establish a cell-autonomous antiviral response. Notably, the loss of IRF7 particularly in astrocytes resulted in a high IFN-I production. Sustained production of IFN-I in astrocytes is independent of an IRF7-mediated positive feedback loop. Conclusion: IFN-I induction in the CNS is profoundly regulated in a cell type-specific fashion. [ABSTRACT FROM AUTHOR]

Interferon regulatory factor (IRF) 7 was originally identified as master transcriptional factor that produced IFN-I and regulated innate immune response, subsequent studies have revealed that IRF7 performs a multifaceted and versatile functions in multiple biological processes. In this review, we provide a comprehensive overview on the current knowledge of the role of IRF7 in immunity and autoimmunity. We focus on the latest regulatory mechanisms of IRF7 in IFN-I, including signaling pathways, transcription, translation, and posttranslational levels, the dimerization and nuclear translocation, and the role of IRF7 in IFN-III and COVID-19. In addition to antiviral immunity, we also discuss the role and mechanism of IRF7 in autoimmunity, and the further research will expand our understanding of IRF7. [ABSTRACT FROM AUTHOR]

Rabies, a highly fatal zoonotic disease, is a significant global public health threat. Currently, the pathogenic mechanism of rabies has not been fully elucidated, and no effective treatment for rabies is available. Increasing evidence shows that the tripartite-motif protein (TRIM) family of proteins participates in the host's regulation of viral replication. Studies have demonstrated the upregulated expression of tripartite-motif protein 21 (TRIM21) in the brain tissue of mice infected with the rabies virus. Related studies have shown that TRIM21 knockdown inhibits RABV replication, while overexpression of TRIM21 exerted the opposite effect. Knockdown of interferon-alpha and interferon-beta modulates the inhibition of RABV replication caused by TRIM21 knockdown and promotes the replication of the virus. Furthermore, our previous study revealed that TRIM21 regulates the secretion of type I interferon during RABV infection by targeting interferon regulatory factor 7 (IRF7). IRF7 knockdown reduced the inhibition of RABV replication caused by the knockdown of TRIM21 and promoted viral replication. TRIM21 regulates RABV replication via the IRF7-IFN axis. Our study identified TRIM21 as a novel host factor required by RABV for replication. Thus, TRIM21 is a potential target for rabies treatment or management. [ABSTRACT FROM AUTHOR]

During viral infection, host defensive proteins either enhance the host immune response or antagonize viral components directly. In this study, we report on the following two mechanisms employed by zebrafish mitogen-activated protein kinase kinase 7 (MAP2K7) to protect the host during spring viremia of carp virus (SVCV) infection: stabilization of host IRF7 and degradation of SVCV P protein. In vivo, map2k7+/- (map2k7-/- is a lethal mutation) zebrafish showed a higher lethality, more pronounced tissue damage, and more viral proteins in major immune organs than the controls. At the cellular level, overexpression of map2k7 significantly enhanced host cell antiviral capacity, and viral replication and proliferation were significantly suppressed. Additionally, MAP2K7 interacted with the C terminus of IRF7 and stabilized IRF7 by increasing K63-linked polyubiquitination. On the other hand, during MAP2K7 overexpression, SVCV P proteins were significantly decreased. Further analysis demonstrated that SVCV P protein was degraded by the ubiquitin-proteasome pathway, as the attenuation of K63-linked polyubiquitination was mediated by MAP2K7. Furthermore, the deubiquitinase USP7 was indispensable in P protein degradation. These results confirm the dual functions of MAP2K7 during viral infection. [ABSTRACT FROM AUTHOR]

We have developed a platform for quantitative genetic interaction mapping using viral infectivity as a functional readout and constructed a viral host-dependency epistasis map (vE-MAP) of 356 human genes linked to HIV function, comprising >63,000 pairwise genetic perturbations. The vE-MAP provides an expansive view of the genetic dependencies underlying HIV infection and can be used to identify drug targets and study viral mutations. We found that the RNA deadenylase complex, CNOT, is a central player in the vE-MAP and show that knockout of CNOT1, 10, and 11 suppressed HIV infection in primary T cells by upregulating innate immunity pathways. This phenotype was rescued by deletion of IRF7, a transcription factor regulating interferon-stimulated genes, revealing a previously unrecognized host signaling pathway involved in HIV infection. The vE-MAP represents a generic platform that can be used to study the global effects of how different pathogens hijack and rewire the host during infection.

Interferon regulatory factor 7 (IRF7) is known as the master transcription factor of the type I interferon response in mammalian species along with IRF3. Yet birds only have IRF7, while they are missing IRF3, with a smaller repertoire of immune-related genes, which leads to a distinctive immune response in chickens compared to in mammals. In order to understand the functional role of IRF7 in the regulation of the antiviral response against avian influenza virus in chickens, we generated IRF7-/- chicken embryonic fibroblast (DF-1) cell lines and respective controls (IRF7wt) by utilizing the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) system. IRF7 knockout resulted in increased viral titers of low pathogenic avian influenza viruses. Further RNA-sequencing performed on H6N2-infected IRF7-/- and IRF7wt cell lines revealed that the deletion of IRF7 resulted in the significant down-regulation of antiviral effectors and the differential expression of genes in the MAPK (mitogen-activated protein kinase) and mTOR (mechanistic target of rapamycin) signaling pathways. Dynamic gene expression profiling of the host response between the wildtype and IRF7 knockout revealed potential signaling pathways involving AP1 (activator protein 1), NF-κB (nuclear factor kappa B) and inflammatory cytokines that may complement chicken IRF7. Our findings in this study provide novel insights that have not been reported previously, and lay a solid foundation for enhancing our understanding of the host antiviral response against the avian influenza virus in chickens.

Interferon regulatory factor 7 (IRF7), a member of the interferon regulatory factors (IRFs) family, is located downstream of the pattern recognition receptors (PRRs)-mediated signaling pathway and is essential for the production of type I interferon (IFN-I). Activation of IRF7 inhibits various viral and bacterial infections and suppresses the growth and metastasis of some cancers, but it may also affect the tumor microenvironment and promote the development of other cancers. Here, we summarize recent advances in the role of IRF7 as a multifunctional transcription factor in inflammation, cancer and infection by regulating IFN-I production or IFN-I-independent signaling pathways. [ABSTRACT FROM AUTHOR]

Interferon regulatory factors (IRFs) are key elements of antiviral innate responses that regulate the transcription of interferons (IFNs) and IFN-stimulated genes (ISGs). While the sensitivity of humancoronaviruses to IFN shasbeencharacterized, antiviral roles of IRFs during human coronavirus infection are not fully understood. Type I or II IFN treatment protected MRC5 cells from human coronavirus 229E infection, but not OC43. Cells infected with 229E or OC43 upregulated ISGs, indicating that antiviral transcription is not suppressed. Antiviral IRFs, IRF1, IRF3 and IRF7, were activated in cells infected with 229E, OC43 or severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2). RNAi knockdown and overexpression of IRFs demonstrated that IRF1 and IRF3 have antiviral properties against OC43, while IRF3 and IRF7 are effective in restricting 229E infection. IRF3activation effectively promotes transcriptionof antiviral genes duringOC43or229Einfection. Our study suggests that IRFsmay be effective antiviral regulators against human coronavirus infection. [ABSTRACT FROM AUTHOR]

Introduction: COVID-19 has been a major focus of scientific research since early 2020. Due to its societal, economic, and clinical impact worldwide, research efforts aimed, among other questions, to address the effect of host genetics in susceptibility and severity of COVID-19.Methods: We, therefore, performed next-generation sequencing of coding and regulatory regions of 16 human genes, involved in maintenance of the immune system or encoding receptors for viral entry into the host cells, in a subset of 60 COVID-19 patients from the General Hospital Tešanj, Bosnia and Herzegovina, classified into three groups of clinical conditions of different severity (“mild,” “moderate,” and “severe”).Results: We confirmed that the male sex and older age are risk factors for severe clinical picture and identified 13 variants on seven genes (CD55, IL1B, IL4, IRF7, DDX58, TMPRSS2, and ACE2) with potential functional significance, either as genetic markers of modulated susceptibility to SARS-CoV-2 infection or modifiers of the infection severity. Our results include variants reported for the first time as potentially associated with COVID-19, but further research and larger patient cohorts are required to confirm their effect.Discussion: Such studies, focused on candidate genes and/or variants, have a potential to answer the questions regarding the effect of human genetic makeup on the expected infection outcome. In addition, loci we identified here were previously reported to have clinical significance in other diseases and viral infections, thus confirming a general, broader significance of COVID-19-related research results following the end of the pandemic period.

Ferroptosis is implicated in the progression of ulcerative colitis (UC), and interferon regulatory factor 7 (IRF7) contributes to cell death. This study probed the mechanism of IRF7 in ferroptosis of colonic epithelial cells (ECs) in mice with dextran sodium sulfate (DSS)-induced UC. The UC mouse model and the in vitro ferroptosis model were respectively established by DSS feeding and the treatment with FIN56 (a ferroptosis inducer). Results of quantitative real-time polymerase chain reaction and western blotting revealed the upregulation of IRF7 and solute carrier family 11 member 2 (SLC11A2/NRAMP2/DMT1) and the downregulation of microRNA (miR)-375-3p in DSS-treated mice and FIN56-treated ECs. Silencing of IRF7 improved the symptoms of UC in DSS-induced mice and decreased the levels of tumor necrosis factor α, interleukin 6, monocyte chemoattractant protein 1, and interleukin 1β, reactive oxygen species, iron ions, lipid peroxidation, and increased glutathione and glutathione peroxidase 4. Chromatin immunoprecipitation and dual-luciferase assays showed that binding of IRF7 to the miR-375-3p promoter inhibited miR-375-3p expression, and miR-375-3p suppressed SLC11A2 transcription. The rescue experiments revealed that knockdown of miR-375-3p neutralized the role of silencing IRF7 in alleviating ferroptosis of colonic ECs. Overall, IRF7 upregulated SLC11A2 transcription by inhibiting miR-375-3p expression, thereby prompting ferroptosis of colonic ECs and UC progression in DSS-treated mice.

As a TIR domain-containing molecular, sterile a-and armadillo motif-containing protein (SARM) acts as an adaptor in Toll-like receptor (TLR) signaling, and also plays important roles in mediating apoptosis and neuronal injury. In the present study, the ortholog of SARM, named as Lc-SARM, was cloned and identified in large yellow croaker (Larimichthys crocea). The full-length ORF of Lc-SARM consists of 2,154 bp, encoding a protein of 717 amino acids (aa), which is comprised of an N-terminal ARM domain, two SAM domains, and a C-terminal TIR domain. Confocal microscopy revealed that Lc-SARM was mainly distributed in the cytoplasm, and the mRNA expression level of Lc-SARM was broadly distributed in all the detected organs/tissues, with the highest expression level found in the brain. The expression patterns of Lc-SARM could be induced in response to poly I:C, LPS, PGN stimulations, and Pseudomonas plecoglossicida infection. Notably, although the overexpression of Lc-SARM could significantly induce NF-kB, IRF3, IRF7, and type I IFN promoter activation, whereas the co-expression of Lc-SARM with Lc-TRIF, Lc-TRAF3, Lc-IRF3, or Lc-IRF7 significantly down-regulated the induction of NF-kB, IRF3, IRF7, or type I IFN promoter activation, and suppressed the antiviral effects as well as the downstream antiviralrelated genes expression compared to the only overexpression of Lc-TRIF, Lc-TRAF3, Lc-IRF3, or Lc-IRF7. Co-immunoprecipitation (Co-IP) assays also demonstrated that Lc-SARM interacts separately with Lc-TRIF, Lc-TRAF3, Lc-IRF3, and Lc-IRF7. It is thus collectively suggested that Lc-SARM functions as a negative regulator in Lc-TRIF, Lc-TRAF3, and Lc-IRF3/7 involved antiviral signaling. [ABSTRACT FROM AUTHOR]

TGF-β-activated kinase-1 (TAK1), tightly related to innate immunity, is phosphorylated and activated by X-linked protein kinase (PRKX) in humans and mammals, which belongs to the c-AMP-dependent protein kinase family. However, the relationship between PRKX and TAK1 remains unknown in teleost. It has been reported in vertebrates for the first time that TAK1 of black carp (bcTAK1) interacts with bcIRF7 and is capable to up-regulate bcIRF7- mediated IFN signaling in our previous study. In this study, the role of PRKX homologue of black carp (Mylopharyngodon piceus) (bcPRKX) in bcTAK1/IFN signaling has been explored. Overexpression of bcPRKX suppressed the transcription of interferon promoters but enhanced the transcription of NFκB promoter. Mylopharyngodon piceus kidney (MPK) cells transfected with shRNA targeting bcPRKX gene presented enhanced antiviral activity against spring viremia of carp virus (SVCV), in which the mRNA levels of the antiviral proteins were increased, including MX1, Viperin and PKR. Overexpressed bcPRKX dampened bcTAK1/bcIRF7/IFN signaling in the luciferase reporter assay and plaque assay. The interaction between bcTAK1 and bcPRKX has been identified by the immunofluorescence (IF) staining and coimmunoprecipitation (co-IP) assay. In addition, we found that bcPRKX can trigger the degradation of bcTAK1. However, the lysosome inhibitor chloroquine, but not the proteasome inhibitor MG-132, prevented the bcTAK1 degradation mediated by bcPRKX. Thus, we conclude that bcPRKX inhibits bcTAK1/bcIRF7/IFN signaling during the innate immune activation by targeting bcTAK1 and triggers lysosome-dependent degradation of bcTAK1. [ABSTRACT FROM AUTHOR]

Interferon regulatory factor (IRF) 3 and IRF7 are master regulators of type I interferon (IFN‐I)‐dependent antiviral innate immunity. Upon viral infection, a positive feedback loop is formed, wherein IRF7 promotes further induction of IFN‐I in the later stage. Thus, it is critical to maintain a suitably low level of IRF7 to avoid the hyperproduction of IFN‐I. In this study, we find that early expression of IFN‐I‐dependent STAT1 promotes the expression of XAF1 and that XAF1 is associated specifically with IRF7 and inhibits the activity of XIAP. XAF1‐knockout and XIAP‐transgenic mice display resistance to viral infection, and this resistance is accompanied by increases in IFN‐I production and IRF7 stability. Mechanistically, we find that the XAF1‐XIAP axis controls the activity of KLHL22, an adaptor of the BTB‐CUL3‐RBX1 E3 ligase complex through a ubiquitin‐dependent pathway. CUL3‐KLHL22 directly targets IRF7 and catalyzes its K48‐linked ubiquitination and proteasomal degradation. These findings reveal unexpected functions of the XAF1‐XIAP axis and KLHL22 in the regulation of IRF7 stability and highlight an important target for antiviral innate immunity. Synopsis: A XAF1‐XIAP‐KLHL22 axis functions as a major regulator to control IRF7 protein abundance and helps maintaining proper IFN‐I production. XAF1‐KO and XIAP transgenic mice display resistance to viral infection.XAF1‐KO and XIAP transgenic mice show increased IFN‐I production and IRF7 stability.KLHL22 directly targets IRF7, catalyzes its K48‐linked ubiquitination and promotes its proteasomal degradation.The XAF1‐XIAP axis controlls the activity of KLHL22 through ubiquitin‐dependent pathways. [ABSTRACT FROM AUTHOR]

Background: Parkinson's disease (PD) is one of the most devastating neurodegenerative disorders and is associated with oxidative stress injury (OSI) and inflammatory responses. This study sought to investigate the mechanism of ovarian tumour domain‐containing ubiquitin aldehyde binding 1 (OTUB1) in OSI and inflammatory responses in PD, providing a theoretical foundation for PD treatment. Methods: The PD mouse model was established by an intraperitoneal injection of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine, followed by behavioural tests, observation of brain pathological changes, and quantification of inflammatory (TNF‐α, IL‐1β, and IL‐10) and OS (ROS, SOD, and MDA) factors. Next, the expression levels of OTUB1, interferon regulatory factor 7 (IRF7), and NADPH oxidase 4 (NOX4) levels were determined by real‐time quantitative polymerase chain reaction and western blot assay, the binding of OTUB1 to IRF7 was analysed by co‐immunoprecipitation, and the ubiquitination level of IRF7 and the enrichment and binding of IRF7 and the NOX4 promoter were measured by chromatin immunoprecipitation and dual‐luciferase assays. Afterwards, rescue experiments were performed with IRF7 or NOX4 overexpression in OTUB1 knockout PD mice. Results: OTUB1 was upregulated in brain tissues of PD mice. Inhibition of OTUB1 alleviated PD progression, OSI, and inflammatory responses. OTUB1 stabilized IRF7 through deubiquitination, and IRF7 bound to the NOX4 promoter to promote NOX4 expression. IRF7 or NOX4 overexpression reversed the effects of silencing OTUB1 on OSI and inflammatory responses in PD mice. Conclusion: OTUB1‐mediated deubiquitination stabilized IRF7 and upregulated NOX4 expression, thereby promoting OSI and inflammatory responses in PD mice. [ABSTRACT FROM AUTHOR]

Background Occurrence of vitiligo was reported in patients treated with IFN (Interferons) for melanoma, hepatitis C, and hepatitis B. This suggests IFN and its immunoregulatory factors may play a role in the pathogenesis of vitiligo. However, the immunopathogenesis remains largely unknown. Objective Explore the role of immunoregulatory factor 7 (IRF7) and immune-regulatory factor 3 (IRF3) in the serum of vitiligo patients. Methods We studied (n=94) vitiligo patients and compared them with healthy control subjects. All included subjects were submitted to full history taking, dermatological examination, VASI score calculation. IRF7 and IRF3 levels were assessed by IRF7 and IRF3 Immunoassay ELISA kit. Results Serum IRF-7 and IRF-3 are not elevated in vitiligo patients, and is associated with the least severity of the disease. Conclusion Our data suggest that the serum levels of type 1 IFN (IRF7) and (IRF3) are not implicated in vitiligo pathogenesis. However, Age and duration of disease showed a negative correlation with IRF3 serum levels with statistically significant correlation. [ABSTRACT FROM AUTHOR]

Type I interferon (IFN) response is the first line of host-based innate immune defense against viral infections. However, viruses have developed multiple strategies to counter host IFN responses, so they may continue infecting hosts via effective replication. Avian reovirus (ARV), an RNA virus, causes viral arthritis or tenosynovitis in chickens. Previous studies have shown that ARV is highly resistant to the antiviral effects of IFN. However, the underlying mechanisms that enable ARV to block the IFN pathway remain unclear. In this study, we found that ectopic expression of ARV protein, σA, significantly inhibited the production of IFN-β induced by melanoma-differentiation-associated gene 5 (MDA5) and poly(I·C). Knockdown of σA during ARV infection enhances the IFN-β response and suppresses viral replication. ARV σA inhibited the MDA5-mediated IFN-β activation by targeting interferon regulatory factor 7 (IRF7). Further studies demonstrated that σA interacts with IRF7, thereby blocking IRF7 dimerization and nuclear translocation, finally leading to the inhibition of IFN-β production. These findings reveal a novel mechanism that allows ARV to evade host antiviral immunity.IMPORTANCE ARV, the causative agent of viral arthritis or tenosynovitis in chickens, has a significant economic impact as it results in poor weight gain and increased feed conversion ratios. The MDA5-mediated IFN-β signal pathway plays an important role in host antiviral defense. Therefore, RNA viruses have developed mechanisms to counter this signaling pathway and successfully establish infection. However, the strategies adopted by ARV to block MDA5-IRF7 signaling remain unclear. In the current study, we demonstrated that ARV σA inhibits this pathway by binding to IRF7, which blocked IRF7 dimerization and nuclear translocation. Our findings may provide insights into how avian reovirus counteracts the innate antiviral immunity of the host to ensure viral replication. [ABSTRACT FROM AUTHOR]

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a multifaceted clinical syndrome characterized by mineral imbalances, abnormalities in bone metabolism, chronic inflammation and vascular calcification. Etelcalcetide, a second-generation intravenous calcimimetic agent, has been approved for treating high-turnover renal osteodystrophy, effectively targeting the pathophysiological mechanisms underlying this condition. We investigate the impacts of etelcalcetide on osteoclast (OC) differentiation and functionality in CKD-MBD via three critical mechanisms: inflammation initiated by interferon regulatory factor 7 (IRF7), receptor-interacting protein (RIP)-mediated necroptosis and apoptosis-induced cell death. The low-dose (CKD + L) or high-dose (CKD + H) of etelcalcetide groups significantly improved biochemical markers compared to the CKD control mice. Additionally, etelcalcetide-treated CKD mice significantly improved cortical and trabecular bone parameters. In an in vitro study, etelcalcetide was observed to bolster the IRF7-mediated IFNβ response in OC differentiation. Furthermore, it stimulated RIP-mediated necroptosis via RIP and MLKL activation, inhibiting bone resorption. Moreover, the drug increased levels of caspases 3 and 9, inducing cell death in OCs. These findings suggest that etelcalcetide regulates bone metabolism and reduces skeletal issues in CKD-MBD. Etelcalcetide likely enhances bone parameters in CKD-MBD mice by regulating IRF7 pathways and inhibiting OC differentiation. It also improves bone health and promotes RIP-mediated necroptosis and apoptosis pathways within OCs. [ABSTRACT FROM AUTHOR]

The production of type I interferon is tightly regulated to prevent excessive immune activation. However, the role of selective autophagy receptor SQSTM1 in this regulation in teleost remains unknown. In this study, we cloned the triploid fish SQSTM1 (3nSQSTM1), which comprises 1371 nucleotides, encoding 457 amino acids. qRT-PCR data revealed that the transcript levels of SQSTM1 in triploid fish were increased both in vivo and in vitro following spring viraemia of carp virus (SVCV) infection. Immunofluorescence analysis confirmed that 3nSQSTM1 was mainly distributed in the cytoplasm. Luciferase reporter assay results showed that 3nSQSTM1 significantly blocked the activation of interferon promoters induced by 3nMDA5, 3nMAVS, 3nTBK1, and 3nIRF7. Co-immunoprecipitation assays further confirmed that 3nSQSTM1 could interact with both 3nTBK1 and 3nIRF7. Moreover, upon co-transfection, 3nSQSTM1 significantly inhibited the antiviral activity mediated by TBK1 and IRF7. Mechanistically, 3nSQSTM1 decreased the TBK1 phosphorylation and its interaction with 3nIRF7, thereby suppressing the subsequent antiviral response. Notably, we discovered that 3nSQSTM1 also interacted with SVCV N and P proteins, and these viral proteins may exploit 3nSQSTM1 to further limit the host's antiviral innate immune responses. In conclusion, our study demonstrates that 3nSQSTM1 plays a pivotal role in negatively regulating the interferon signaling pathway by targeting 3nTBK1 and 3nIRF7. • 3nSQSTM1 negatively regulates the interferon signaling. • 3nSQSTM1 interacts with 3nTBK1 and 3nIRF7. • 3nSQSTM1 interacts with SVCV N and P proteins. [ABSTRACT FROM AUTHOR]

This study aimed to elucidate the biological roles and regulatory mechanisms of B-cell lymphoma 7 protein family member A (BCL7A) in acute myeloid leukemia (AML), particularly its interaction with polypyrimidine tract binding protein 1 (PTBP1) and the effects on cancer progression and drug resistance. BCL7A expression levels were analyzed in AML tissues and cell lines, focusing on associations with promoter hypermethylation. Interaction with PTBP1 and effects of differential expression of BCL7A were examined in vitro and in vivo. The impacts on cell proliferation, cycle progression, apoptosis, and differentiation were studied. Additionally, the regulatory roles of BCL7A on interferon regulatory factor 7 (IRF7) and 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) were assessed. BCL7A was downregulated in AML due to promoter hypermethylation and negatively regulated by PTBP1. Upregulation of BCL7A impeded AML cell growth, induced apoptosis, promoted cell differentiation, and decreased cell infiltration into lymph nodes, enhancing survival in mouse models. Overexpression of BCL7A upregulated IRF7 and downregulated HMGCS1, linking to reduced AML cell malignancy and decreased resistance to cytarabine. BCL7A acts as a tumor suppressor in AML, inhibiting malignant progression and enhancing drug sensitivity through the IRF7/HMGCS1 pathway. These findings suggest potential therapeutic targets for improving AML treatment outcomes. [Display omitted] [ABSTRACT FROM AUTHOR]

Tumor necrosis factor receptor-associated factors (TRAFs) play vital roles in tumor necrosis factor receptor (TNF-R) and interleukin-1 receptor/Toll-like receptor (IL-1R/TLR) mediated signaling pathway. However, the role that TRAF7 plays in the host immune responses is largely unknown in comparison to the extensive and in-depth research that has been conducted on other members of the TRAF family. Notably, Lc-TRAF7, a cloned TRAF7 ortholog, was discovered in the large yellow croaker (Larimichthys crocea) in the current study, which has an open reading frame (ORF) of 1,962 base pairs and encodes a protein of 653 amino acids (aa). Lc-TRAF7 is consisted of a RING finger domain, a coiled-coil domain, and seven WD40 domains, with the genomic organization consisted of 20 exons and 19 introns. According to the expression analysis, Lc-TRAF7 was presented in a wide range of detected organs and tissues of the healthy fish, and was able to significantly induced by stimulations of poly I:C, LPS, PGN, and Pseudomonas plecoglossicida infection. Subcellular distribution analysis revealed that Lc-TRAF7 was a cytoplasmic protein, with the RING finger and coiled-coil domain function importantly in its subcellular localization. Luciferase assays demonstrated that Lc-TRAF7 overexpression significantly induced the activation of NF-κB, IRF3, IRF7, and IFN1 promoters. In addition, the WD40 domains play a pivotal role in the NF-κB promoter activation, whereas the RING finger and coiled-coil domain were essential in the IRF3, IRF7, and IFN1 promoter activation. Notably, Lc-TRAF7 overexpression could suppress SVCV proliferation in EPC cells, and the expression levels of IRF3, IRF7, ISG15, ISG56, RSAD2, and TNF-α were up-regulated under Lc-TRAF7 overexpression in LYCMS cells. These findings collectively implied that Lc-TRAF7 may function as an important regulator in the host antiviral responses via the NF-κB as well as IRF3/7 involved signaling pathways.

During mammalian viral infections, interferon regulatory factor 7 (IRF7) partners with IRF3 to regulate the type I interferon response. In chickens, however, it is still unclear how IRF7 functions in the host innate immune response, especially given that IRF3 is absent. To further elucidate the functional role of chicken IRF7 during avian influenza virus (AIV) infection, we generated inducible IRF7 overexpression DF-1 cell lines and performed in vitro infection using low pathogenic AIVs (LPAIVs). Overexpression of IRF7 resulted in higher viral replication of H6N2 and H10N7 LPAIVs compared to empty vector control cells regardless of IRF7 expression level. In addition, a high rate of induced cell death was observed due to elevated level of IRF7 upon viral infection. RNA-seq and subsequent transcriptome analysis of IRF7 overexpression and control cells discovered candidate genes possibly controlled by chicken IRF7. Functional annotation revealed potential pathways modulated by IRF7 such as TGF-beta signaling pathway, FoxO signaling pathway and cell structural integrity related pathways. Next, we analyzed the host response alteration due to the IRF7 overexpression and additionally discovered the possible connection of chicken IRF7 and JAK-STAT signaling pathway. These findings suggest that chicken IRF7 could modulate a wide range of cellular processes in the host innate immune response thus meticulous control of IRF7 expression is crucial to the host in response to AIV infection.

Lili Guo,1 Te Fang,1 Yanhua Jiang,1 Dingsheng Liu2 1Department of Anesthesiology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning, 110001, People’s Republic of China; 2Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, 110004, Liaoning, People’s Republic of ChinaCorrespondence: Dingsheng LiuDepartment of General Surgery, Shengjing Hospital, China Medical University, No. 36 Sanhao St, Heping District, Shenyang, 110004, Liaoning, People’s Republic of ChinaEmail Dingsheng-liu@hotmail.comBackground: Stomach adenocarcinoma (STAD) is one of the most prevalent malignances, ranking fifth in incidence and third in mortality among all malignances. Interferon regulatory factors (IRFs) play a vital role in immune response and tumor cellular biological process. The roles of IRFs in STAD are far from being systematically clarified.Methods: A series of bioinformatics tools, including GEPIA, UALCAN, TIMER, Kaplan–Meier plotter and LinkedOmics, were applied to explore the expression and clinical significance of IRFs in STAD.Results: IRF3/7 expression were upregulated in STAD in sub-group analyses based on race, gender, age, H. Pylori infection status, histological subtypes, tumor grade, individual cancer stages, and nodal metastasis status. High IRF3/7 expression were associated with poor overall survival (OS), post-progression survival (PFPS) and first progression (FP) in STAD. IRF3 and IRF7 were altered in 5% and 6% of all TCGA STAD patients. Further analysis revealed that IRF7 was significantly associated with the abundance of immune cells (B cells, Neutrophils and Dendritic cells) and the expression of most immune biomarkers. Enrichment analysis indicated that IRF7 was mainly involved in adaptive immune response, NOD-like receptor signaling pathway, Necroptosis, and Toll-like receptor signaling pathway. We also identified several IRF7-associated kinase and miRNA targets in STAD. The result of verified experiment revealed that ITF7 expression was increased in STAD tissues compared with normal tissues and prognosis analysis revealed that STAD patients with high IRF7 expression had a poor overall survival.Conclusion: IRF7 is upregulated in STAD and associated with poor OS, PPS and FP. Moreover, IRF7 is significantly associated with the abundance of immune cells and the expression of most immune biomarkers, suggesting that IRF7 is as a prognostic biomarker and associated with immune infiltration in STAD.Keywords: stomach adenocarcinoma, bioinformatics analysis, immune infiltration, IRF7

During an infection, hematopoiesis is altered to increase the output of mature myeloid cells to fight off the pathogen. Despite convincing evidence that hematopoietic stem and progenitor cells (HSPCs) can sense pathogens directly, more mechanistic studies are needed to reveal whether pattern recognition receptor (PRR) signaling initiates myeloid development directly, or indirectly through the production of cytokines by HSPCs that can act in an autocrine/paracrine manner, or by a combination of both direct and indirect mechanisms. In this study, we have used an in vitro model of murine HSPCs to study myeloid differentiation in response to the TLR2 ligand Pam3CSK4 and showed that, besides indirect mechanisms, TLR2 stimulation of HSPCs promotes myelopoiesis directly by initiating a MyD88-dependent signaling. This direct differentiation program involves a combined activation of the transcription factors PU.1, C/EBPβ, and IRF7 driven by TBK1 and PI3K/mTOR. Notably, downstream of MyD88, the activated TBK1 kinase can activate mTOR directly and IRF7 induction is mediated by both TBK1 and mTOR. TLR2 signaling also induces NF-κB dependent IL-6 production that may further induce indirect myeloid differentiation. Our results have identified the direct signaling pathways and the transcription factors involved in macrophage development from HSPCs in response to TLR2 engagement, a critical process to trigger a rapid immune response during infection. TLR2-induced signaling pathways that drive myeloid differentiation in HSPCs. MyD88 is recruited upon Pam3CSK4 binding to TLR1/TLR2, activating TBK1, and the PI3K/mTORC1 pathway. This results in the expression of transcription factors IRF7, PU.1, and C/EBPβ, which drive direct macrophage differentiation. TLR2 signaling also induces NF-κB-dependent release of IL-6 that can act in an autocrine/paracrine manner inducing indirect macrophage differentiation. [ABSTRACT FROM AUTHOR]