Expression Of Interferon Regulatory Factor Research Articles

Analysis of structure–activity relationship of indol-3-yl-N-phenylcarbamic amides as potent STING inhibitors

A structure–activity relationship (SAR) study of stimulator of interferon gene (STING) inhibition was performed using a series of indol-3-yl-N-phenylcarbamic amides and indol-2-yl-N-phenylcarbamic amides. Among these analogs, compounds 10, 13, 15, 19, and 21 inhibited the phosphorylation of STING and interferon regulatory factor 3 (IRF3) to a greater extent than the reference compound, H-151. All five analogs showed stronger STING inhibition than H-151 on the 2′,3′-cyclic GMP-AMP-induced expression of interferon regulatory factors (IRFs) in a STINGR232 knock-in THP-1 reporter cell line. The half-maximal inhibitory concentration of the most potent compound, 21, was 11.5 nM. The molecular docking analysis of compound 21 and STING combined with the SAR study suggested that the meta- and para-positions of the benzene ring of the phenylcarbamic amide moiety could be structurally modified by introducing halides or alkyl substituents.

Lutein suppresses ferroptosis of cardiac microvascular endothelial cells via positive regulation of IRF in cardiac hypertrophy

Cardiac microvascular dysfunction contributes to cardiac hypertrophy (CH) and can progress to heart failure. Lutein is a carotenoid with various pharmacological properties, such as anti-apoptotic, anti-inflammatory, and antioxidant effects. Limited research has been conducted on the effects of lutein on pressure overload-induced CH. Studies have shown that CH is accompanied by ferroptosis in the cardiac microvascular endothelial cells (CMECs). This study aimed to investigate the effect of lutein on ferroptosis of CMECs in CH. The transcription factor interferon regulatory factor (IRF) is associated with immune system function, tumor suppression, and apoptosis. The results of this study suggested that pressure overload primarily inhibits IRF expression, resulting in endothelial ferroptosis. Administration of lutein increased the expression of IRF, providing protection to endothelial cells during pressure overload. IRF silencing downregulated solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) expression, leading to the induction of ferroptosis in CMECs. Lutein supplementation suppressed endothelial ferroptosis by upregulating IRF. These data suggest that IRF may function as a transcription factor for SLC7A11 and that lutein represses ferroptosis in CMECs by upregulating IRF expression. Therefore, targeting IRF may be a promising therapeutic strategy for effective cardioprotection in patients with CH and heart failure.

The transcription factor IRF4 determines the anti-tumor immunity of CD8+ T cells

Understanding the factors that regulate Tcell infiltration and functional states in solid tumors is crucial for advancing cancer immunotherapies. Here, we discovered that the expression of interferon regulatory factor 4 (IRF4) was a critical Tcell intrinsic requirement for effective anti-tumor immunity. Mice with T-cell-specific ablation of IRF4 showed significantly reduced Tcell tumor infiltration and function, resulting in accelerated growth of subcutaneous syngeneic tumors and allowing the growth of allogeneic tumors. Additionally, engineered overexpression of IRF4 in anti-tumor CD8+ Tcells that were adoptively transferred significantly promoted their tumor infiltration and transition from a naive/memory-like cell state into effector Tcell states. As a result, IRF4-engineered anti-tumor Tcells exhibited significantly improved anti-tumor efficacy, and inhibited tumor growth either alone or in combination with PD-L1 blockade. These findings identify IRF4 as a crucial cell-intrinsic driver of Tcell infiltration and function in tumors, emphasizing the potential of IRF4-engineering as an immunotherapeutic approach.

IRF8 in Conjunction With CD123 and CD20 to Distinguish Lupus Erythematosus Panniculitis From Subcutaneous Panniculitis-like T-Cell Lymphoma.

Distinguishing lupus erythematosus panniculitis (LEP) from subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a diagnostic challenge with important clinical implications. Immunohistochemical expression of interferon regulatory factor 8 (IRF8) has been shown to highlight cells with plasmacytoid dendritic cell differentiation. Considering that the presence of plasmacytoid dendritic cells highlighted by CD123 immunolabeling is a well-described feature that supports LEP over SPTCL, we hypothesized that IRF8 immunohistochemistry can be used as a diagnostic test to improve accuracy in differentiating LEP from SPTCL. In this study, we assessed the expression of IRF8, CD123, and CD20 in 35 cutaneous biopsies from 31 distinct patients, which included 22 cases of LEP and 13 cases of SPTCL. We found that clusters of IRF8-positive cells within the dermis, and away from subcutaneous fat, could discriminate LEP from SPTCL ( P =0.005). Similarly, CD123-positive clusters in any location were observed in LEP but absent in all cases of SPTCL. In addition, we found that dermal CD20-predominant lymphoid aggregates could help discriminate LEP from SPTCL ( P =0.022). As individual assays, IRF8, CD123, and CD20 were highly specific (100%, 100%, and 92%, respectively) though poorly sensitive (45%, 29%, and 50%, respectively). However, a panel combining IRF8, CD123, and CD20, with at least 1 positive marker was more accurate than any individual marker by receiver operating characteristic curve analysis. Our study provides a rationale for potentially including IRF8 as part of an immunohistochemical panel composed of other currently available markers used to differentiate LEP from SPTCL.

Expression of programmed death-ligand 1, IRF1 and CD8 T lymphocyte infiltration in a primary subset of breast cancer patients in Sudan

ObjectivesThis study aimed to investigate the protein expression of programmed death ligand 1 (PD-L1) in breast cancer (BC) tissues and link this data with estrogen status, the expression of interferon regulatory factor1 (IRF-1), and CD8+T lymphocyte infiltration by immunohistochemistry (IHC). We also attempted to identify the association between PD-L1 expression, the cell proliferation index marker (Ki67), and lymph node involvement. MethodsOne hundred and fifty formalin-fixed and paraffin-embedded (FFPE) blocks of breast tissue were acquired from Sudanese females via The National Public Health Laboratory. FFPE blocks were subjected to antigen/antibody detection by IHC with antibodies raised against PD-L1, IRF1, and CD8. These data were analyzed alongside data extracted from medical records relating to estrogen receptor (ER) status, Ki67 index, and lymph node (LN) status. ResultsIHC analysis revealed a significant association between PD-L1 and CD8 (p = 0.010). In addition, regression analysis indicated the ability of IRF1 to induce PD-L1 expression levels in IRF1-positive cases that were two-fold higher than IRF1-deficient cases (odds ratio [OR]: 2.441 p = 0.035). Analysis also suggested that PD-L1 exerts impact on cell proliferation, as reflected by the Ki67 index. An independent t test showed that higher Ki67 scores were more frequent among PD-L1-positive patients than in PD-L1-negative patients (t = 2.608 p = 0.014). There was an inverse association between PD-L1 and ER status; ER-positive tumors exhibited negative PD-L1 expression and vice versa (p = 0.04). Furthermore, we investigated the prognostic value of PD-L1 by evaluating the association between PD-L1 and LNs dispersed variably with tumor cells; there was no statistically significant relationship between these factors (p > 0.05). ConclusionThe expression of PD-L1 and IRF-1, along with the infiltration of CD8, represents a potent panel of biomarkers with which to identify BC patients with the highest probabilities of achieving an excellent response to immune therapy, particularly when taking ER status into account, as ER expression levels are known to be high when immune checkpoint blockers (ICBs) generate a poor response.

Inhibition of IL-4/STAT6/IRF4 signaling reduces the epithelial-mesenchymal transition in eosinophilic chronic rhinosinusitis with nasal polyps.

Previous studies have shown that epithelial-to-mesenchymal transition (EMT) in nasal epithelial cells is critical for tissue remodeling of chronic rhinosinusitis with nasal polyps (CRSwNP). However, the precise mechanism underlying the EMT remains poorly understood. This study aimed to investigate the role of interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (STAT6)/interferon regulatory factor 4 (IRF4) signaling pathway on EMT in eosinophilic CRSwNP. We performed quantitative real-time polymerase chain reaction, immunohistochemistry, immunofluorescent staining, and Western blotting to evaluate the expression of STAT6, IRF4, and EMT markers in sinonasal mucosal samples. Effects of IL-4-induced EMT were determined using primary human nasal epithelial cells (hNECs) from patients with eosinophilic CRSwNP. Wound scratch assay, cell morphology, Western blotting, and immunofluorescence cytochemistry were performed to evaluate EMT, and EMT-related markers. Next, human THP-1 monocytic cells were stimulated by phorbolate-12-myristate-13-acetate to differentiate into M0 and were subsequently polarized into M1 with lipopolysaccharide and interferon-γ, M2 with IL-4. The markers of the macrophage phenotype were assessed by Western blotting. The co-culture system was built to explore the interaction between macrophages (THP-1 cells) and hNECs. After co-culture with M2 macrophages, EMT-related markers of primary hNECs were evaluated by immunofluorescence cytochemistry and Western blotting. Enzymelinked immunosorbent assays were used to detect transforming growth factor beta 1 (TGF-β1) in THP-1-derived supernatants. STAT6 and IRF4 mRNA and protein expression were significantly upregulated in both eosinophilic and noneosinophilic nasal polyps compared with control tissues. The expression of STAT6 and IRF4 in eosinophilic nasal polyps was higher than those in noneosinophilic nasal polyps. STAT6 and IRF4 were not only expressed in epithelial cells but also in macrophages. The number of STAT6+CD68+ cells and IRF4+CD68+ cells in eosinophilic nasal polyps was higher than those in noneosinophilic nasal polyps and control tissues. EMT was enhanced in eosinophilic CRSwNP compared to the healthy controls and noneosinophilic CRSwNP. IL-4-stimulated human nasal epithelial cells exhibited EMT characteristics. The hNECs co-cultured with M2 macrophages demonstrated high levels of EMT-related markers. The TGF-β1 level was significantly induced by IL-4 and elevated (M2) rather than control macrophages. The inhibition of STAT6 by AS1517499 reduced the expression of IRF4 in epithelial cells and macrophages and counteracted IL-4-induced EMT in epithelial cells. In eosinophilic nasal polyps, IL-4 induces STAT6 signaling to upregulate IRF4 expression in epithelial cells and macrophages. IL-4 promotes EMT of hNECs through the STAT6/IRF4 signaling pathway. IL-4-induced M2 macrophages enhanced EMT of hNECs. Inhibition of STAT6 can downregulate the expression of IRF4 and suppress the EMT process, thus providing a new strategy for the treatment of nasal polyps.

Hypomethylated interferon regulatory factor 8 recruits activating protein-2α to attenuate porcine epidemic diarrhea virus infection in porcine jejunum.

Interferon regulatory factor 8 (IRF8) is a key regulator of innate immune receptor signaling that resists pathogen invasion by regulating cell growth and differentiation. Porcine epidemic diarrhea virus (PEDV) targets the intestine and damages the mucosal barrier. However, whether IRF8 regulates PEDV replication remains unclear. We revealed that PEDV infection activated IRF8 expression. Moreover, IRF8 deletion drastically promoted PEDV replication and invasion, increasing the virus copies and titers. Hypomethylation enrichment of activating protein (AP)-2α was significantly negatively correlated with high IRF8 expression, and AP-2α directly targeted the IRF8 promoter to regulate PEDV replication. Furthermore, IRF8 overexpression decreased the cellular reactive oxygen species levels and mitochondrial membrane potential and increased the antioxidant enzyme activities to alleviate PEDV-induced oxidative damage. IRF8 overexpression suppressed apoptotic gene expression, thereby inhibiting apoptosis in response to PEDV stimulation. Taken together, this study demonstrates that AP-2α is involved in PEDV-induced epigenetic modification of IRF8 to reduce cell apoptosis and oxidative stress and facilitate host resistance to PEDV in the intestinal epithelium.

Therapeutic efficacy of the resorcylic acid lactone LL-Z1640-2 for adult T-cell leukaemia/lymphoma.

Adult T-cell leukaemia/lymphoma (ATL) remains incurable. The NF-κB and interferon regulatory factor 4 (IRF4) signalling pathways are among the critical survival pathways for the progression of ATL. TGF-β-activated kinase 1 (TAK1), an IκB kinase-activating kinase, triggers the activation of NF-κB. The resorcylic acid lactone LL-Z1640-2 is a potent irreversible inhibitor of TAK1/extracellular signal-regulated kinase 2 (ERK2). We herein examined the therapeutic efficacy of LL-Z1640-2 against ATL. LL-Z1640-2 effectively suppressed the in vivo growth of ATL cells. It induced in vitro apoptosis and inhibited the nuclear translocation of p65/RelA in ATL cells. The knockdown of IRF4 strongly induced ATL cell death while downregulating MYC. LL-Z1640-2 as well as the NF-κB inhibitor BAY11-7082 decreased the expression of IRF4 and MYC at the protein and mRNA levels, indicating the suppression of the NF-κB-IRF4-MYC axis. The treatment with LL-Z1640-2 also mitigated the phosphorylation of p38 MAPK along with the expression of CC chemokine receptor 4. Furthermore, the inhibition of STAT3/5 potentiated the cytotoxic activity of LL-Z1640-2 against IL-2-responsive ATL cells in the presence of IL-2. Therefore, LL-Z1640-2 appears to be an effective treatment for ATL. Further studies are needed to develop more potent compounds that retain the active motifs of LL-Z1640-2.

Expression of Interferon Regulatory Factor 8 (IRF8) and Its Association with Infections in Dialysis Patients.

Patients on dialysis have dysfunctions of innate and adaptive immune system responses. The transcriptional factor IRF8 (interferon regulatory factor 8) is primarily expressed in plasmacytoid cells (pDCs) and myeloid dendritic cells (mDCs), playing a crucial role in the maturation of dendritic cells, monocytes, and macrophages, and contributing to protection against bacterial infections. The current study analyzed the expression patterns of IRF8 and assessed its association with the risk of infections in 79 dialysis patients compared to 44 healthy controls. Different subsets of leukocytes and the intracellular expression of IRF8 were measured using flow cytometry. Compared to the healthy controls, the dialysis patients showed significantly reduced numbers of pDCs and significantly increased numbers of natural killer cells and classical and intermediate monocytes. The dialysis patients exhibited decreased numbers of IRF8-positive dendritic cells (pDC p < 0.001, mDC1 p < 0.001, mDC2 p = 0.005) and increased numbers of IRF8-positive monocytes (p < 0.001). IRF8 expression in pDC, mDC, and classical monocytes was lower in the dialysis patients than in the controls. Dialysis patients who required hospitalization due to infections within one year of follow-up displayed significantly reduced IRF8 expression levels in pDCs compared to patients without such infections (p = 0.04). Our results suggest that reduced IRF8 expression in pDCs is a potential risk factor predisposing dialysis patients to serious infections.

Ginsenoside Rh2 promotes hepatic stellate cell ferroptosis and inactivation via regulation of IRF1-inhibited SLC7A11

BackgroundSustained liver fibrosis may lead to cirrhosis. Activated hepatic stellate cells (HSCs) are crucial for liver fibrosis development. Ferroptosis, a newly iron-dependent regulated cell death, has been demonstrated to be involved in HSC inactivation. PurposeGinsenoside Rh2 (GRh2), a natural bioactive product derived from ginseng, has been shown to promote HSC inactivation. However, the effect of GRh2 on HSC ferroptosis remains unclear. MethodsWe explored the effects of GRh2 on liver fibrosis in vivo and in vitro. RNA-sequence analysis was performed in HSCs after GRh2 treatment. The crosstalk between ferroptotic HSCs and macrophages was also explored. ResultsGRh2 alleviated liver fibrosis in vivo. In vitro, GRh2 reduced HSC proliferation and activation via ferroptosis, with increased intracellular iron, reactive oxygen species, malondialdehyde and glutathione depletion. The expression of SLC7A11, a negative regulator of ferroptosis, was obviously reduced by GRh2. Interestingly, interferon regulatory factor 1 (IRF1), a transcription factor, was predicted to bind the promoter region of SCL7A11. The interaction between IRF1 and SCL7A11 was further confirmed by the results of chromatin immunoprecipitation and luciferase reporter assays. Furthermore, loss of IRF1 led to an increase in SCL7A11, which contributed to the suppression of HSC ferroptosis and the enhancement of HSC activation in GRh2-treated HSCs. Further studies revealed that GRh2-induced HSC ferroptosis contributed to the inhibition of macrophage recruitment via regulation of inflammation-related genes. Moreover, GRh2 caused a reduction in liver inflammation in vivo. ConclusionCollectively, GRh2 up-regulates IRF1 expression, resulting in the suppression of SLC7A11, which contributes to HSC ferroptosis and inactivation. GRh2 ameliorates liver fibrosis through enhancing HSC ferroptosis and inhibiting liver inflammation. GRh2 may be a promising drug for treating liver fibrosis.

IRF4 is required for migration of CD4+ T cells to the intestine but not for Th2 and Th17 cell maintenance.

The transcription factor Interferon Regulatory Factor 4 (IRF4) is central in control of T cell activation and differentiation. Deficiency of IRF4 results in severe immune deficiency and affects maturation and function of most if not all T cell subsets. Here we use mouse infection models for Citrobacter rodentium and Strongyloides ratti to analyze the function of IRF4 in T helper (Th) 17 and Th2 cell responses, respectively. IRF4 deficient mice were impaired in the control of both pathogens, failed to mount Th17 and Th2 cell responses and showed impaired recruitment of T helper cells to the intestine, the infection site of both pathogens. Compromised intestinal migration was associated with reduced expression of the intestinal homing receptors α4β7 integrin, CCR9 and GPR15. Identification of IRF4 binding sites in the gene loci of these receptors suggests a direct control of their expression by IRF4. Competitive T cell transfer assays further demonstrated that loss of one functional Irf4 allele already affected intestinal accumulation and Th2 and Th17 cell generation, indicating that lower IRF4 levels are of disadvantage for Th2 and Th17 cell differentiation as well as their migration to the intestine. Conversion of peripheral CD4+ T cells from an Irf4 wildtype to an Irf4 heterozygous or from an Irf4 heterozygous to a homozygous mutant genotype after C. rodentium or S. ratti infection did not reduce their capacity to produce Th17 or Th2 cytokines and only partially affected their persistence in the intestine, revealing that IRF4 is not essential for maintenance of the Th2 and Th17 phenotype and for survival of these T helper cells in the intestine. In conclusion, we demonstrate that the expression levels of IRF4 determine Th2 and Th17 cell differentiation and their intestinal accumulation but that IRF4 expression is not crucial for Th2 and Th17 cell survival.

Calpeptin may reverse glucocorticoid-resistance of allergic rhinitis associated with cigarette smoke exposure by down-regulating interferon regulatory factor 1

Cigarette smoke exposure is an important factor in chronic inflammation in patients with allergic rhinitis (AR); however, the relationship between cigarette smoke and AR-related glucocorticoid resistance requires further study. In mice, calpeptin significantly reduces inflammation of the lower respiratory tract caused by cigarette smoke, but whether it can treat glucocorticoid-resistant AR caused by cigarette smoke requires further research. In this study, we confirmed that cigarette smoke exposure can aggravate the Th2 inflammatory response in AR leading to glucocorticoid resistance. The underlying mechanism may be related to decreased expression of DNA methyltransferase 3a (Dnmt3a), and increased expression of interferon regulatory factor 1 (IRF1). In addition, we found that calpeptin can inhibit the expression of IRF1 and thus treat AR-associated glucocorticoid resistance in rats exposed to cigarette smoke. These data suggest that calpeptin may downregulate IRF1 and therefore treat glucocorticoid resistance in AR-associated with cigarette smoke exposure.

IRF3 in adipose tissue inflammation and metabolism

Abstract Dysfunction of adipocytes and adipose tissue is a primary defect in obesity and obesity-associated metabolic diseases. Interferon regulatory factor 3 (IRF3) has been implicated in adipogenesis. However, the role of IRF3 in obesity and obesity associated disorders still remains unclear. Here we show that IRF3 expression in human adipose tissue was positively associated with insulin sensitivity and negatively associated with type 2 diabetes. In mouse preadipocytes, IRF3 not only acts as a brake negatively regulating the adipogenic transcriptional network centered on the PPARg pathway, but also is important for the functionality of adipocytes. In macrophages, IRF3 inhibits inflammatory cytokine expression through IFNb/IL-10 axis, thereby restraining adipose tissue inflammation in obesity. Mice deficient in IRF3 developed obesity and type 2 diabetes spontaneously associated with increased adipose tissue inflammation. This study demonstrates that IRF3 regulates the biology of multiple cell types including adipocytes and macrophages to prevent the development of obesity and obesity-related complications, hence, could be a target for therapeutic interventions for prevention and treatment of obesity-associated metabolic disorders. National Medical Research Council of Singapore

CCL17 Blockade by CCL17mAb/GSK-J4 Ameliorates Hyperalgesia in a Rat Model of Postoperative Pain.

C-C motif chemokine ligand 17 (CCL17), an important chemokine, plays a vital role in regulating immune balance in the central nervous system. In this study, we explored the potential roles of CCL17 in a rat postoperative pain model and that of blocking CCL17 in the prevention of postoperative pain in rats. A right plantar incision in rat was used as a model of postoperative pain. A behavioral change was measured preoperatively and postoperatively using mechanical withdrawal thresholds and thermal withdrawal latency. CCL17 and its upstream Jmjd-3 mRNA levels in the spinal cord were detected using real-time PCR, CCL17 levels in the serum were measured using enzyme-linked immunosorbent assay (ELISA), and the expression of interferon regulatory factor 4 (IRF4), which interacts with Jmjd-3, was detected by immunohistochemistry staining. After that, rats were intraperitoneally injected with either anti-CCL17 monoclonal antibody (mAb) or GSK-J4 (the Jmjd3 inhibitor) to evaluate the protective effects of blocking CCL17 on postoperative pain. We found that CCL17 and Jmjd-3 were significantly increased in the spinal cords of the postoperative pain rat, consistent with changes in hyperalgesia. In addition, our results showed that the mechanical and thermal allodynia was significantly ameliorated using anti-CCL17mAb or GSK-J4. Moreover, we found that anti-CCL17mAb or GSK-J4 treatment decreased c-fos expression in response to peripheral stimulation. Finally, our preliminary exploration found that anti-CCL17mAb or GSK-J4 had a protective effect on tissue damage. These findings indicated that high expression of CCL17 played a critical role in postoperative pain induced by plantar incision and that CCL17 blockade may serve as an effective approach to managing postoperative pain.

Extracellular vesicles from bone marrow mesenchymal stem cells alleviate acute rejection injury after liver transplantation by carrying miR-22-3p and inducing M2 polarization of Kupffer cells.

Acute rejection (AR) is a major problem following liver transplantation. Extracellular vesicles (EVs) are involved in various pathological processes including liver disease. The present study investigated the effect of EVs derived from bone marrow mesenchymal stem cells (BMSCs) on AR injury after orthotopic liver transplantation (OLT) in mice. BMSCs and EVs were isolated and identified. The OLT mouse model was established using Kamada's two-cuff method and injection with EVs, followed by liver function detection and measurement of inflammatory cytokines (interleukin-10, interferon-γ, and tumor necrosis factor-α), M1 and M2 markers (tumor necrosis factor-α, inducible nitric oxide synthase, resistin like alpha, and Arg1) were detected. Kupffer cells (KCs) were cultured and treated with lipopolysaccharides. miR-22-3p expression was detected. The effect of EVs-shuttled miR-22-3p on Kupffer cell polarization was studied. Binding relation of miR-22-3p and interferon regulatory factor 8 (IRF8) was verified. The effect of IRF8 on KC polarization was verified. BMSC-EV treatment enhanced liver function of OLT mice and alleviated AR and apoptosis, which were annulled after removing KCs. EVs induced KC M2 polarization. Mechanically, EVs carried miR-22-3p into KCs, upregulated miR-22-3p in KCs, and inhibited IRF8 expression. Upregulation of IRF8 in KCs inhibited EV-induced KC M2 polarization. BMSCs-EVs carry miR-22-3p into KCs and upregulate miR-22-3p, inhibit IRF8 expression, induce KC M2 polarization, and attenuate AR injury after liver transplantation.

ZBP1 mediates the progression of Alzheimer's disease via pyroptosis by regulating IRF3.

Alzheimer's disease (AD) is one of the leading causes of death throughout the world. Z-DNA binding protein 1 (ZBP1), a DNA-related gene, is associated with inflammation, and its expression is altered in AD brain. We aimed to elucidate the exact role of ZBP1 in AD development and its potential regulatory mechanism. First, we constructed both in vivo and in vitro models of AD and investigated the ZBP1 expression profile. A loss-of-function assay was performed by transfecting lentivirus carrying ZBP1 short hairpin RNA (shRNA). By evaluating cell death, oxidative stress, inflammation response and pyroptosis, the function of ZBP1 was validated. Finally, the correlation between ZBP1 and interferon regulatory factor 3 (IRF3) was verified. We also performed rescue experiments to validate the crucial role of IRF3 in ZBP1-mediated AD progression. According to our results, ZBP1 was upregulated in AD rat tissue and AD neurons. Silencing ZBP1 dramatically decreased cell injury, oxidative stress and inflammation in AD neurons and improved the cognitive function of AD rats. Additionally, IRF3 expression and phosphorylation were significantly elevated during AD development and positively correlated with ZBP1. Taken together, silencing ZBP1 suppressed cell injury and pyroptosis of AD neurons and improved cognitive function of AD rats via inhibiting IRF3. These findings might provide a novel insight for AD target diagnosis and therapy.

Loss of IRF8 inhibits the growth of acute myeloid leukemia cells.

The transcription factor interferon regulatory factor 8 (IRF8), as a member of the IRF family, is essential for myeloid cell differentiation. However, the precise role of IRF8 in the pathogenesis of acute myeloid leukemia (AML) remains unknown. By using multivariate analysis, we discovered that high IRF8 expression was an independent poor predictor of overall survival (OS) in AML patients from our clinical follow-up study. The proliferation of three AML cell lines was significantly inhibited by shRNA-mediated knockdown of IRF8, owing to cell cycle S-phase arrest. Furthermore, we demonstrated that knocking down IRF8 could suppress the expression of CyclinA and CyclinB1, resulting in a shift in cell cycle distribution. Loss of IRF8 in AML cells decreased the expression of STAT3 and phosphor-STAT3 (pSTAT3), which are key factors in JAK/STAT signal pathway and are important for AML progression. Using a xenograft mouse model, we discovered the antiproliferative effect of losing IRF8 in vivo. In conclusion, this study found that IRF8 may play a prognostic factor and therapeutic target in AML.

A Small Molecule RIG-I Agonist Serves as an Adjuvant to Induce Broad Multifaceted Influenza Virus Vaccine Immunity.

Retinoic acid-inducible gene I (RIG-I) is essential for activating host cell innate immunity to regulate the immune response against many RNA viruses. We previously identified that a small molecule compound, KIN1148, led to the activation of IFN regulatory factor 3 (IRF3) and served to enhance protection against influenza A virus (IAV) A/California/04/2009 infection. We have now determined direct binding of KIN1148 to RIG-I to drive expression of IFN regulatory factor 3 and NF-κB target genes, including specific immunomodulatory cytokines and chemokines. Intriguingly, KIN1148 does not lead to ATPase activity or compete with ATP for binding but activates RIG-I to induce antiviral gene expression programs distinct from type I IFN treatment. When administered in combination with a vaccine against IAV, KIN1148 induces both neutralizing Ab and IAV-specific T cell responses compared with vaccination alone, which induces comparatively poor responses. This robust KIN1148-adjuvanted immune response protects mice from lethal A/California/04/2009 and H5N1 IAV challenge. Importantly, KIN1148 also augments human CD8+ T cell activation. Thus, we have identified a small molecule RIG-I agonist that serves as an effective adjuvant in inducing noncanonical RIG-I activation for induction of innate immune programs that enhance adaptive immune protection of antiviral vaccination.

MUM-1 in canine lymphoma: A pilot study.

Expression of interferon regulatory factor 4 (IRF4)/multiple myeloma oncogene-1 (MUM1) in peripheral T-cell lymphoma (PTCL) in people is associated with a poorer survival outcome compared to cases of PTCL lacking MUM1 expression. The aim of this study was to determine whether MUM1 is expressed in canine peripheral T-cell lymphoma not otherwise specified (PTCL-NOS). For comparison, the presence of MUM1 antigen was also investigated in canine diffuse large B cell lymphoma (DLBCL). Nine cases of PTCL-NOS and 9 cases of DLBCL diagnosed by a commercial veterinary diagnostic laboratory were selected. Positive immunohistochemical labeling for MUM1 was observed in PTCL-NOS (2 out of 9 cases) and DLBCL (3 out of 9 cases). These findings suggest that a subset of neoplastic T and B lymphocytes can express MUM1. The role of MUM1 in the biological behavior and outcome of canine lymphoma (CL) requires further investigation on a larger number of cases.

CD36 neutralisation blunts TLR2-IRF7 but not IRF3 pathway in neonatal mouse brain and immature human microglia following innate immune challenge

Innate immune response in neonatal brain is associated with a robust microglial activation and induction of Toll-like Receptors (TLRs). To date, the role of the scavenger receptor CD36 in TLRs modulation, particularly TLR2 signaling, has been well established in adult brain. However, the crosstalk between TLR4, TLR2 and CD36 and its immunogenic influence in the neonatal brain remains unclear. In this study, using a CD36 blocking antibody (anti-CD36) at post-natal day 8, we evaluated the response of neonates to systemic endotoxin (lipopolysaccharide; LPS) challenge. We visualized the TLR2 response by bioluminescence imaging using the transgenic mouse model bearing the dual reporter system luciferase/green fluorescent protein under transcriptional control of a murine TLR2 promoter. The anti-CD36 treatment modified the LPS induced inflammatory profile in neonatal brains, causing a significant decrease in inflammatory cytokine levels and the TLR2 and TLR3 mediated signalling.The interferon regulatory factor 3 (IRF3) pathway remained unaffected. Treatment of the LPS-challenged human immature microglia with anti-CD36 induced a marked decrease in TLR2/TLR3 expression levels while TLR4 and IRF3 expression was not affected, suggesting the shared CD36 regulatory mechanisms in human and mouse microglia. Collectively, our results indicate that blocking CD36 alters LPS-induced inflammatory profile of mouse and human microglia, suggesting its role in fine-tuning of neuroinflammation.