IFN-β Expression Research Articles

OMP38 of Carbapenem-Resistant Acinetobacter Baumannii-Mediated mtDNA Release Activates the cGAS-STING Signaling to Induce Inflammatory Response.

Carbapenem-resistant Acinetobacter baumannii (CRAB) has become a major threat in the treatment of bacterial infection, and immunotherapy in a non-antibiotic-dependent manner is an effective way to overcome CRAB infection. However, the role of the innate immune response in CRAB infection is poorly understood. Here, it is reported that CRAB infection induced a cytosolic DNA-sensing signaling pathway and significant IFN-β production in mice post-CRAB infection. The knockout of STING reduced bacterial burden, the production of inflammatory cytokines, and lung injury in mice post CRAB infection. The cytosolic DNA sensor cyclic GMP-AMP synthase (cGAS) and the adaptor protein stimulator of interferon genes (STING) are required for CRAB-induced IFN-β expression in macrophages. Intriguingly, CRAB utilized outer membrane vesicles (OMVs) to transport outer membrane protein 38 (OMP38) into mitochondria, triggering mitochondrial DNA (mtDNA) release into the cytosol through the mitochondrial permeability transition pore (mPTP) and activating the cGAS-STING signaling. Finally, epigallocatechin gallate (EGCG) is demonstrated to block the activation of the cGAS-STING pathway and ameliorate CRAB-induced excessive inflammatory response. These results demonstrated that the early innate immune response to CRAB infection is activated in a cGAS-STING-dependent manner, which could be a potential therapeutic target for CRAB infection.

Host-derived Bacillus antagonistic novel duck reovirus infection by regulating gut microbiota-mediated immune responses

The Novel Duck Reovirus (NDRV) infection poses a significant health risk to ducks, primarily attributed to the absence of efficacious preventive measures. This research aimed to investigate whether the administration of isolated Bacillus could protect antagonistic NDRV infection in a Cherry Valley duck model. Four indigenous Bacillus strains from the feces of healthy ducks demonstrated promising biosafety profiles. One-day-old ducklings were inoculated intramuscularly with NDRV and subsequently subjected to a 28-day regimen of mixed Bacillus (Bac) treatment. The effects of Bac on pathological symptoms, immune response and intestinal flora were analyzed. The results showed that Bac significantly reduced weight loss, clinical symptoms, and viral loading. Moreover, Bac treatment significantly decreased neutrophils, monocytes proportion, the TNF-α, IL-1β and IL-6 expression, increased platelets, lymphocytes proportion, the IFN-β and IL-10 expression, and restored immune dysfunction. In addition, Bac has increased the relative abundance of Enterococcaceae, Lactobacillales, Bacilli, Ruminococcaceae, Clostridium and Phascolarctobacterium. Moreover, the metabolism of short-chain fatty acids (SCFAs) was further regulated, thereby enhancing the acetate content. The correlation analysis showed that a positive association between acetate levels and IFN-β expression, while a negative correlation was observed with viral loading. In conclusion, the results suggest that the anti-NDRV mechanism of Bac may involve the modulation of gut microbiota to elicit an immune response that inhibits viral infection. This study presents a novel approach for the prevention and treatment of NDRV, thereby establishing a theoretical foundation for the future development of probiotics in the prevention and treatment of NDRV.

CGAS/STING pathway modulation in polyhexamethyleneguanidine phosphate-induced immune dysregulation and pulmonary fibrosis using human monocytic cells (THP-1) and male C57BL/6 mice

ABSTRACT Polyhexamethyleneguanidine phosphate (PHMG), a widely used antimicrobial agent, has been implicated in humidifier disinfectant-associated lung injuries (HDLI). PHMG exposure suppressed interferon regulatory factor 3 (IRF3) activation and interferon-β (IFN-β) expression induced by a cGAS agonist or a STING agonist in human monocytic cells (THP-1), which are known to transition to alveolar macrophages during pulmonary fibrosis development. However, the mechanisms underlying PHMG-induced pulmonary toxicity in lung remain unclear. Thus, it was of interest to investigate the effects of PHMG on the innate immune system in male C57BL/6 mouse, focusing on the cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) pathway and potential role in pulmonary fibrosis. Intratracheal administration of PHMG (1 or 2 mg/kg) in mice resulted in lung fibrosis, as evidenced by H&E staining with Szapiel scoring, Masson’s trichrome staining with Ashcroft scoring, and increased mRNA levels of TGF-β and collagen type I. Interestingly, lower dose of PHMG enhanced IFN-β production in the lungs, whereas higher dose decreased IFN-β levels, indicating a biphasic effect that initially promotes inflammation but ultimately impairs host defense mechanisms, leading to pulmonary fibrosis. Our findings demonstrate the critical role of the cGAS/STING pathway in PHMG-induced mouse lung injury and suggest that targeting this pathway might serve as a potential therapeutic strategy for treating pulmonary fibrosis.

NEIL1 block IFN-β production and enhance vRNP function to facilitate influenza A virus proliferation

Influenza A virus (IAV) has developed multiple tactics to hinder the innate immune response including the epigenetic regulation during IAV infection, but the novel epigenetic factors and their mechanism in innate immunity remain well studied. Here, through a non-biased high-throughput sgRNA screening of 1041 known epigenetic modifiers in a cellular model of IAV-induced interferon-beta (IFN-β) production, we identified nei endonuclease VIII-like 1 (NEIL1) as a critical regulator of IFN-β in response to viral infection. Further studies showed that NEIL1 promoted the replication of the influenza virus by regulating the methylation of cytonuclear IFN-β promoter (mainly CpG-345), inhibiting the expression of IFN-β and IFN-stimulating genes. The structural domains of NEIL1, especially the catalytic domain, were critical for the suppression of IFN-β production, but the enzymatic activity of NEIL1 was dispensable. Furthermore, our results revealed that NEIL1 relied on interactions with the N- and C-terminus of the nucleoprotein (NP) of IAV, and NEIL1 expression facilitated the entry of the NP into the nucleus, which further enhanced the stability of the viral ribonucleoprotein (vRNP) complex and thus contributed to IAV replication and transcription. These findings reveal an enzyme-independent mechanism of host NEIL1 that negatively regulates IFN-β expression, thereby facilitating IAV propagation. Our study provides new insights into the roles of NEIL1, both in directly promoting virus replication and in evading innate immunity in IAV infection.

Deleting Trim33 in myeloid cells improves the efficiency of radiotherapy through an interferon beta dependent anti-tumor immune response.

Radiotherapy (RT) triggers an immune response that contributes to anti-tumor effects. Induction of interferon beta (IFN-β) is a key event in this immunogenicity of RT. We have previously shown that TRIM33, a chromatin reader, restrains IFN-β expression in Toll-like receptor-activated myeloid cells. Here, we explored whether deleting Trim33 in myeloid cells might improve the radio-induced immune response, and subsequent efficiency of RT. We first established that Trim33-/- bone marrow-derived macrophages showed increased expression of IFN-β in response to direct irradiation, or to treatment with irradiated cancer cells, further supporting our hypothesis. We then tested the efficiency of a single dose RT in three subcutaneous and one orthotopic tumor models. In all situations, myeloid deletion of Trim33 led to a significantly improved response after RT, leading to a complete and durable response in most of the treated mice bearing orthotopic oral tumors. This effect required the IFN-I pathway, and the presence of CD8+ T lymphocytes, but not NK cells. In addition, cured mice were capable of rejecting a secondary tumor challenge, demonstrating an in situ vaccination effect. We conclude that deleting Trim33 in myeloid cells improves RT efficiency, through a mechanism involving the IFN-I pathway and the immune response. Our work suggests that myeloid Trim33 is a host factor affecting the tumor response to RT, thus representing a new potential therapeutic target for modifying RT responses.

Riluzole Enhancing anti-PD-1 Efficacy by Activating cGAS/STING Signaling in Colorectal Cancer.

Colorectal cancer is the second leading cause of cancer mortality in the US. Although immune checkpoint blockade therapies including anti-PD-1/PD-L1 have been successful in treating a subset of colorectal cancer patients, response rates remain low. We have found that riluzole, a well-tolerated FDA-approved oral medicine for treating amyotrophic lateral sclerosis, increased intratumoral CD8+ T cells and suppressed tumor growth of colon cancer cells in syngeneic immune competent mice. Riluzole-mediated tumor suppression was dependent on the presence of CD8+ T cells. Riluzole activates the cytosolic DNA sensing cGAS/STING pathway in colon cancer cells, resulting in increased expression of interferon β (IFNβ) and IFNβ-regulated genes including CXCL10. Inhibition of ATM, but not ATR, resulted in a synergistic increase in IFNβ expression, suggesting that riluzole induces ATM-mediated damage response that contribute to cGAS/STING activation. Depletion of cGAS or STING significantly attenuated riluzole-induced expression of IFNβ and CXCL10 as well as increase of intratumoral CD8+ T cells and suppression of tumor growth. These results indicate that riluzole-mediated tumor infiltration of CD8+ T cells and attenuation of tumor growth is dependent on tumor cell intrinsic STING activation. To determine whether riluzole treatment primes the tumor microenvironment for immune checkpoint modulation, riluzole was combined with anti-PD-1 treatment. This combination showed greater efficacy than either single agent, and strongly suppressed tumor growth in vivo. Taken together, our studies indicate that riluzole activates cGAS/STING-mediated innate immune responses, which might be exploited to sensitize colorectal tumors to anti-PD-1/PD-L1 therapies. .

Increasing coil temperature of a third-generation e-cigarette device modulates C57BL/6 mouse lung immune cell composition and cytokine milieu independently of aerosol dose

ABSTRACT Higher coil temperature in e-cigarette devices increases the formation of aerosols and toxicants, such as carbonyls. At present, the health implications of vaping at higher temperatures, including exacerbation of pulmonary inflammation, are largely unknown when aerosol dose is considered. To isolate the pulmonary effects of coil temperature, C57BL/6 mice were exposed to e-cigarette aerosols generated at lower (190°C) or higher (250°C) temperature for 3 days, while maintaining a similar chamber aerosol concentration. Increasing coil temperature did not markedly alter aerosol mass-normalized emissions of select carbonyls formed from thermal degradation pathways including formaldehyde, acetaldehyde, propionaldehyde, and acetone under the tested environment. Total bronchoalveolar cells, primarily macrophages, were significantly decreased in mice exposed to aerosols generated with higher coil temperatures compared to lower temperature exposures. The gene expression of IFNβ, IL-1β, TNFα, and IL-10 in mouse lung tissue was significantly reduced following e-cigarette exposure under both conditions, compared to filtered air exposure. Higher temperature exposures further exacerbated downregulation of IFNβ and IL-1β. Data suggest that higher temperature vaping might modulate acute pulmonary immune responses, potentially inducing immune suppression, even when normalized for aerosol dose exposure. Coil temperature thus appears to be an important parameter that needs to be regulated to ensure harm reduction for e-cigarette users.

Regulation and Dynamics of IFN-β Expression Revealed with a Knockin Reporter Mouse.

IFN-β is a potent antiviral cytokine and the first member of the type I IFN family of cytokines to be induced during the antiviral response. IFN-β plays an essential protective role in host defense against virus infections, as well as a pathogenic role in numerous autoimmune and autoinflammatory disorders. However, contemporary tools to study the induction, kinetics, and behavior of IFN-β are lacking. In this study, we describe a knockin Ifnb-IRES-TdTomato-Cre reporter mouse to track IFN-β-expressing cells. We demonstrate pathway-specific induction of the TdTomato reporter and show that the linked Cre recombinase enables permanent marking of cells that express IFN-β. We identify a robust MAVS-dependent IFN-β response in lung epithelial cells following Sendai virus infection invivo. Finally, we find that activation of RNase L in macrophages by RNA ligands of the RIG-I-like receptors prevents protein translation of IFN-β and the TdTomato reporter. Our mouse model provides a powerful tool to study the biology of type I IFN induction and the antiviral response.

Swine NONO promotes IRF3-mediated antiviral immune response by Detecting PRRSV N protein.

Non-POU domain-containing octamer-binding protein (NONO) is a multi-functional nuclear protein which belongs to the Drosophila behavior/human splicing (DBHS) protein family. NONO is known to regulate multiple important biological processes including host antiviral immune response. However, whether NONO can inhibit porcine reproductive and respiratory syndrome virus (PRRSV) replication is less well understood. In this study, we demonstrated that swine NONO (sNONO) inhibited PRRSV replication, via increasing expression of IFN-β, whereas NONO knockdown or knockout in PAM-KNU cells was more susceptible to PRRSV infection. As an IRF3 positive regulation factor, NONO promoted IFN-β expression by enhancing activation of IRF3. During PRRSV infection, NONO further up-regulated IRF3-mediated IFN-β expression by interacting with PRRSV N protein. Mechanistically, NONO functioned as a scaffold protein to detect PRRSV N protein and formed N-NONO-IRF3 complex in the nucleus. Interestingly, it was found that the NONO protein reversed the inhibitory effect of PRRSV N protein on type I IFN signaling pathway. Taken together, our study provides a novel mechanism for NONO to increase the IRF3-mediated IFN-β activation by interacting with the viral N protein to inhibit PRRSV infection.

MERS-CoV-nsp5 expression in human epithelial BEAS 2b cells attenuates type I interferon production by inhibiting IRF3 nuclear translocation

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is an enveloped, positive-sense RNA virus that emerged in 2012, causing sporadic cases and localized outbreaks of severe respiratory illness with high fatality rates. A characteristic feature of the immune response to MERS-CoV infection is low type I IFN induction, despite its importance in viral clearance. The non-structural proteins (nsps) of other coronaviruses have been shown to block IFN production. However, the role of nsp5 from MERS-CoV in IFN induction of human respiratory cells is unclear. In this study, we elucidated the role of MERS-CoV-nsp5, the viral main protease, in modulating the host’s antiviral responses in human bronchial epithelial BEAS 2b cells. We found that overexpression of MERS-CoV-nsp5 had a dose-dependent inhibitory effect on IFN-β promoter activation and cytokine production induced by HMW-poly(I:C). It also suppressed IFN-β promoter activation triggered by overexpression of key components in the RIG-I-like receptor (RLR) pathway, including RIG-I, MAVS, IKK-ε and IRF3. Moreover, the overexpression of MERS-CoV-nsp5 did not impair expression or phosphorylation of IRF3, but suppressed the nuclear translocation of IRF3. Further investigation revealed that MERS-CoV-nsp5 specifically interacted with IRF3. Using docking and molecular dynamic (MD) simulations, we also found that amino acids on MERS-CoV-nsp5, IRF3, and KPNA4 may participate in protein-protein interactions. Additionally, we uncovered protein conformations that mask the nuclear localization signal (NLS) regions of IRF3 and KPNA4 when interacting with MERS-CoV-nsp5, suggesting a mechanism by which this viral protein blocks IRF3 nuclear translocation. Of note, the IFN-β expression was restored after administration of protease inhibitors targeting nsp5, indicating this suppression of IFN-β production was dependent on the enzyme activity of nsp5. Collectively, our findings elucidate a mechanism by which MERS-CoV-nsp5 disrupts the host’s innate antiviral immunity and thus provides insights into viral pathogenesis.

DAMPs Drive Fibroinflammatory Changes in the Glaucomatous ONH.

The optic nerve head (ONH) is well known to be the initial site of glaucomatous damage; however, the molecular mechanisms initiating this pathology are not fully understood. To further understand the initiating factors in glaucomatous damage we utilized a novel mouse model of glaucoma, B6.EDA+/+ mice, which constitutively express fibronectin containing the extra domain A (FN+EDA). FN+EDA is a known damage-associated molecular pattern (DAMP) that activates Toll-like receptor 4 and elicits a fibro-inflammatory response. Eyes from B6.EDA+/+ and C57BL/6J mice were evaluated for retinal ganglion cell (RGC) death, retinal nerve fiber layer (RNFL) thickness, and optic nerve (ON) damage at 12 months and 22 months of age. ONH sections were isolated using laser capture microdissection for subsequent RNA-sequencing and Gene Set Enrichment Analysis (GSEA). GSEA results were confirmed using immunohistochemical (IHC) staining. B6.EDA+/+ mice exhibit significantly higher intraocular pressure, loss of RGCs, thinning of the RNFL, and progressive levels of ON damage at 12 months and 22 months of age compared to C57BL/6J controls. Protein expression of DAMPs FN+EDA and biglycan was significantly increased in B6.EDA+/+ mice compared to C57BL/6J controls. GSEA analysis identified significantly up- and downregulated gene groupings at both 12 months and 22 months of age, and IHC staining at 12 and 18 months of age demonstrated significant increases of IFNα, IFNβ, and pSTAT1 expression in B6.EDA+/+ mice compared to C57BL/6J controls. Our study characterizes glaucomatous changes to the retina, ON, and ONH over the course of 2 years and identifies novel molecular pathways associated with these pathophysiological changes. These data illustrate the effects of FN+EDA on the fibro-inflammatory response in the aging ONH in a novel mouse model of glaucoma.

The pro-inflammatory responses of innate immune cells to Leishmania RNA virus 2-infected L. major support the survival and proliferation of the parasites

Infection of Leishmania by Leishmania RNA virus (LRV) has been proposed as a pathogenic factor that induces pro-inflammatory responses through the TLR3/TLR4 signaling pathway. We investigated the effect of L. major infection by LRV2 on innate immune cell responses (human neutrophil (HL-60) and macrophage (THP-1) cell lines). The expression levels of pro- and anti-inflammatory cytokine and chemokine genes as well as genes involved in the amino acid metabolism of arginine were then investigated by RT-qPCR. Moreover, the expression of TLR genes and their downstream signaling pathways were compared in THP-1 cells infected with the two isolates. Apoptosis was also evaluated in infected THP-1 and HL-60 cells using the PI/Annexin V flow cytometry assay. In both cell lines, the expression of pro-inflammatory cytokines increased in response to LRV2+ L. major (Lm+), and the expression of chemokines shifted toward macrophage recruitment. In contrast to LRV2- L. major (Lm-), Lm + infected THP-1 cells acquired the M2-like phenotype. The presence of LRV2 increased the gene expression of TLRs and their signaling pathways, especially TLR3 and TLR4, which was proportional to the increase in pro-inflammatory cytokines. In addition, Lm + increased the expression of IL-10 and IFN-β, which contribute to the survival and growth of the parasite in the phagolysosome. Altogether, our results showed that Lm + could stimulate pro-inflammatory responses that promote parasite replication and stabilization in the host.

The importance of IFNα2A (Roferon-A) in HSV-1 latency and T cell exhaustion in ocularly infected mice.

Published studies have generated compelling results indicating that type I IFN modulates function of HSV-1 latency-associated transcript (LAT). One member of type I IFN is IFNα2A also called Roferon-A). IFNα2A has been used in monotherapy or in combination therapy with other drugs to treat viral infections and different kinds of cancer in humans. The goal of this study was to determine whether the absence of IFNα2A affects primary and latent infections in ocularly infected mice. Therefore, we generated a mouse strain lacking IFNα2A expression (IFNα2A-/-). Ocular HSV-1 replication, IFN and immune cell expressions on days 3 and 5 post infection (PI), as well as eye disease, survival, latency-reactivation, and T cell exhaustion were evaluated in ocularly infected IFNα2A-/- and wild type (WT) control mice. Absence of IFNα2A did not affect other members of the IFNα family but it affected IFNβ and IFNγ expressions as well as some immune cells on day 5 PI compared to WT mice. Viral replication in the eye, eye disease, and survival amongst ocularly infected IFNα2A-/- mice were similar to that of WT infected mice. The absence of IFNα2A significantly reduced the levels of latency and T cell exhaustion but not time of reactivation compared with control mice. Our results suggest that blocking IFNα2A expression may be a useful tool in reducing latency and the subsequent side effects associated with higher levels of latency.

A Gain-of-Function Cleavage of TonEBP by Coronavirus NSP5 to Suppress IFN-β Expression.

Human coronaviruses (HCoVs) modify host proteins to evade the antiviral defense and sustain viral expansion. Here, we report tonicity-responsive enhancer (TonE) binding protein (TonEBP) as a cellular target of HCoVs. TonEBP was cleaved into N-terminal and C-terminal fragments (TonEBP NT and TonEBP CT, respectively) by NSP5 from all the HCoVs tested. This cleavage resulted in the loss of TonEBP's ability to stimulate the TonE-driven transcription. On the other hand, TonEBP NT promoted viral expansion in association with the suppression of IFN-β expression. TonEBP NT competed away NF-κB binding to the PRD II domain on the IFN-β promoter. A TonEBP mutant resistant to the cleavage by NSP5 did not promote the viral expansion nor suppress the IFN-β expression. These results demonstrate that HCoVs use a common strategy of targeting TonEBP to suppress the host immune defense.

Genomic investigation of innate sensing pathways in the tumor microenvironment

The innate immune system is the first responder to infectious agents, cellular debris, and cancerous growths. This system plays critical roles in the antitumor immune responses by boosting and priming T cell-mediated cytotoxicity but is understudied due to the complexity and redundancy of its various downstream signaling cascades. We utilized a mathematical tool to holistically quantify innate immune signaling cascades and immunophenotype over 8,000 tumors from The Cancer Genome Atlas (TCGA). We found that innate immune activation was predictive of patient mortality in a subset of cancers. Further analysis identified PHF genes as transcripts that were associated with genomic stability and innate activation. Knockdown of PHF gene transcripts in vitro led to an increase in cell death and IFNB1 expression in a cGAS-dependent manner, validating PHF genes as potential anti-tumor targets. We also found an association between innate immune activation and both tumor immunogenicity and intratumor microbes, which highlights the versatility of this model. In conclusion, interrogating activation of innate immune signaling cascades demonstrated the importance of studying innate signaling in cancer and broadened the search for new therapeutic adjuvants.

Azamollugin, a mollugin derivative, has inhibitory activity on MyD88- and TRIF-dependent pathways.

Previously, we reported that azamollugin, an aza-derivative of mollugin, exhibited potent inhibitory activity on NO production in LPS-stimulated RAW 264.7 cells. Further investigations in this study revealed that azamollugin not only suppressed iNOS gene expression regulated by NF-κB, but also inhibited LPS-induced IFN-β expression, which is known to be regulated by IRF3. Azamollugin exhibited an inhibitory activity on LPS-induced IRAK1 activation, suggesting inhibitory effect on the MyD88-dependent pathway. Furthermore, azamollugin inhibited LPS-induced phosphorylation of IRF3 and its upstream factor, TBK1/IKKε, suggesting an inhibitory effect on the TRIF-dependent pathway via TLR4. In addition, azamollugin also suppressed poly(I:C)-induced phosphorylation of TBK1 and IRF3, suggesting an inhibitory effect on the TRIF-dependent pathway via TLR3. These results suggest that azamollugin has inhibitory activity against both the MyD88-dependent and TRIF-dependent pathways, respectively.

A Hirsutella sinensis Alcohol Extract Exerts Bidirectional Immunoregulatory Effects by Regulating Macrophage Polarization.

For background, Hirsutella sinensis, the only anamorphic fungus considered an effective substitute for Cordyceps sinensis, possesses immunoregulatory properties. However, the specific mechanism underlying the immunoregulatory function of Hirsutella sinensis remains unclear. The purpose is to investigate the therapeutic effects of Hirsutella sinensis alcohol extract (HSAE) on immune dysregulation and elucidate the underlying mechanisms involved. For methods, we established inflammatory and immunosuppression models in vitro and in vivo to evaluate the bidirectional immunoregulatory function of HSAE via qRT-PCR and immunoblotting. We also studied its potential mechanism via RNA sequencing and transcriptional analysis. We further established M1 and M2 cell models to explore the effect of HSAE on M1/M2 polarization using qRT-PCR, immunoblotting, and flow cytometry. For results, our data demonstrated enhanced proliferation, phagocytosis, and antipathogenic activities of macrophages. Treatment with HSAE led to increases in the proportions of CD3+ and CD4+ immune cells in cyclophosphamide-induced immunosuppressed mice. Additionally, HSAE reduced the lipopolysaccharide (LPS)-induced expression of Il1b, Il6, Ifnb1, and Cxcl10 by inhibiting the activation of the NF-κB and MAPK pathways in vitro and improved mouse survival by reducing the proportion of M1/M2 macrophages in septic mice. Finally, we found that HSAE inhibited M1 polarization by decreasing the expression of iNOS and CD86 and promoted M2 polarization by increasing the expression of ARG1 and CD206. For conclusions, our study provides evidence that HSAE has the potential to enhance immune responses and suppress excessive inflammation. These effects were realized by modulating macrophage polarization, providing novel insights into the fundamental mechanism underlying the bidirectional immunomodulatory effect of HSAE.

Exploring expression levels of the cGAS-STING pathway genes in peripheral blood mononuclear cells of spinal tuberculosis patients

BackgroundThis study aimed to investigate the differential expression levels of the cGAS-STING pathway in peripheral blood mononuclear cells (PBMCs) of spinal tuberculosis (TB) patients with different progression and its feasibility as a diagnostic marker.MethodsPeripheral blood and medical records of 25 patients with spinal TB and 10 healthy individuals, were prospectively collected and analyzed. PBMCs and serum were extracted from peripheral blood and the expression levels of the cGAS-STING pathway in PBMCs were measured by real-time PCR (RT-PCR) and serum interferon β (IFN-β) expression levels were measured by enzyme-linked immunosorbent assay (ELISA). The expression of Interferon regulatory Factor 3 (IRF3) in PBMCs was measured using western blot. Statistical analysis was performed using the SPSS 26.0 statistical package.ResultsThe results showed that the expression level of the TANK-binding kinase 1 (TBK1) and IRF3 was significantly higher in PBMCs (P < 0.05), in patients with active lesions than in patients with stable lesions. The serum concentration of IFN-β was significantly higher in patients with active lesions (P = 0.028). Compared with healthy individuals, the expression level of the cGAS-STING pathway was elevated in PBMCs of TB patients (P < 0.05), and the difference in the expression level of IFN-β was not statistically significant (P > 0.05), and the serum IFN-β concentration was elevated (P < 0.05). The calculated AUC values for TBK1 and IRF3 in PBMCs, IFN-β in serum and erythrocyte sedimentation rate (ESR) to distinguish between patients with active and stable lesions were 0.732, 0.714, 0.839, and 0.714 respectively.ConclusionsThe expression level of TBK1 and IRF3 in PBMCs, and IFN-β in the serum of patients with spinal TB is positively correlated with disease activity. TBK1 has higher specificity and IFN-β in serum has higher sensitivity when used to differentiate between patients with active and stable lesions.

Metabolic Dependency Shapes Bivalent Antiviral Response in Host Cells in Response to Poly:IC: The Role of Glutamine.

The establishment of effective antiviral responses within host cells is intricately related to their metabolic status, shedding light on immunometabolism. In this study, we investigated the hypothesis that cellular reliance on glutamine metabolism contributes to the development of a potent antiviral response. We evaluated the antiviral response in the presence or absence of L-glutamine in the culture medium, revealing a bivalent response hinging on cellular metabolism. While certain interferon-stimulated genes (ISGs) exhibited higher expression in an oxidative phosphorylation (OXPHOS)-dependent manner, others were surprisingly upregulated in a glycolytic-dependent manner. This metabolic dichotomy was influenced in part by variations in interferon-β (IFN-β) expression. We initially demonstrated that the presence of L-glutamine induced an enhancement of OXPHOS in A549 cells. Furthermore, in cells either stimulated by poly:IC or infected with dengue virus and Zika virus, a marked increase in ISGs expression was observed in a dose-dependent manner with L-glutamine supplementation. Interestingly, our findings unveiled a metabolic dependency in the expression of specific ISGs. In particular, genes such as ISG54, ISG12 and ISG15 exhibited heightened expression in cells cultured with L-glutamine, corresponding to higher OXPHOS rates and IFN-β signaling. Conversely, the expression of viperin and 2'-5'-oligoadenylate synthetase 1 was inversely related to L-glutamine concentration, suggesting a glycolysis-dependent regulation, confirmed by inhibition experiments. This study highlights the intricate interplay between cellular metabolism, especially glutaminergic and glycolytic, and the establishment of the canonical antiviral response characterized by the expression of antiviral effectors, potentially paving the way for novel strategies to modulate antiviral responses through metabolic interventions.

Characterization and functional analysis of chicken promyelocytic leukemia protein

In mammals, promyelocytic leukemia (PML) protein, also named as TRIM19, is the key component of nuclear membrane-less sub structures PML nuclear bodies (PML-NBs) or nuclear domains 10 (ND10). PML-NBs are dynamic foci that consist of numerous permanently or transiently associated proteins. The mammalian PMLs are involved in the regulation of various cellular pathways, including apoptosis, intrinsic and innate antiviral immunity, cell cycle, DNA damage, senescence and etc. Nevertheless, little is known about the role of chicken PML (chPML). In this study, chPML gene was cloned, and its several functions were characterized. We found that chPML was widely expressed in different tissues of chickens, and showed different subcellular distribution pattern in DF-1 cells comparing with LMH and HD11 cells. Like human PML, chPML was identified to be SUMOylated. K463 is one critical SUMOylation site and 240RARRG244 is SUMO interaction motif (SIM) of chPML. Moreover, qPCR showed that chPML could not only up-regulate the expression of host innate immune factor IFN-β and its downstream ISGs, but also antigen presentation-related factors including class II transactivator (CIITA) and MHC II DM beta 2 (DMB2). Notably, over-expression of chIFN-β could promote the expression of endogenous chPML. All these provide novel insights into the function of chPML, and pave the way for further studying the roles of chPML in biological process and anti-infection function.