Search Results (77)

Měnglà virus (MLAV) is a member of the genus Dianlovirus in the family Filoviridae, which also includes Ebola virus (EBOV) and Marburg virus (MARV). Whether MLAV poses a threat to human health is uncertain. However, the MLAV VP35 and VP40 proteins can impair IFNα/β gene expression and block IFNα/β-induced Jak-STAT signaling, respectively, suggesting the capacity to counteract human innate immune defenses. In this study, MLAV VP40 is demonstrated to impair the Sendai virus (SeV)-induced activation of the IFNβ promoter. Inhibition is independent of the MLAV VP40 PPPY late-domain motif that interacts with host proteins possessing WW-domains to promote viral budding. Similar IFNβ promoter inhibition was not detected for EBOV or MARV VP40. MLAV VP40 exhibited lesser capacity to inhibit TNFα activation of an NF-κB reporter gene. MLAV VP40 impaired IFNβ promoter activation by an over-expressed, constitutively active form of RIG-I and by the over-expressed IRF3 kinases TBK1 and IKKε. However, MLAV VP40 did not inhibit IFNβ promoter activation by constitutively active IRF3 5D. Consistent with these findings, MLAV VP40 inhibited SeV-induced IRF3 phosphorylation. Although IRF3 phosphorylation occurs in the cytoplasm, MLAV VP40 exhibits substantial nuclear localization, accumulating in foci in HeLa cell nuclei. In contrast, the VP40 of EBOV and MARV exhibited lower degrees of nuclear localization and did not accumulate in foci. MLAV VP40 interacts with importin alpha-1 (IMPα1), suggesting entry via the IMPα/IMPβ nuclear import pathway. Cumulatively, these data identify novel features that distinguish MLAV VP40 from its homologues in EBOV and MARV. Full article

Swine acute diarrhea syndrome coronavirus (SADS-CoV), initially identified in China in February 2017, severely impacts the swine industry by causing lethal watery diarrhea in neonatal piglets. Understanding the molecular mechanism employed by SADS-CoV to evade the host’s immune defenses is of utmost importance. In this study, using the porcine ileum epithelial cell line IPI-FX as an in vitro model, we investigated the highly pathogenic SADS-CoV GDS04 strain and its nonstructural protein 5 (nsp5) for their roles in inhibiting interferon-beta (IFN-β) production. Our findings indicated that GDS04 inhibited poly(I:C)-induced IFN-β production by impeding the promoter activities of IRF3 and NF-κB. As a 3C-like protease, SADS-CoV nsp5 functioned as an interferon inhibitor by interacting with IKKε, reducing its protein abundance, and inhibiting its phosphorylation. This study enhances our understanding of the interaction between coronaviruses and their hosts, providing novel insights into the evasion of the immune system by coronaviruses. Full article

SARS-CoV-2, a β-coronavirus, primarily affects the lungs, with non-specific lesions and no cytopathic viral effect in the skin. Cutaneous antiviral mechanisms include activation of TLR/IRF pathways and production of type I IFN. We evaluated the antiviral mechanisms involved in the skin of COVID-19 patients, including skin samples from 35 deceased patients who had contracted COVID-19 before the launch of the vaccine. Detection of SARS-CoV-2 in the skin was performed using transmission electron microscopy and RT-qPCR. Microscopic and molecular effects of the virus in skin were evaluated by histopathology, RT-qPCR, and immunohistochemistry (IHC). The results revealed the presence of SARS-CoV-2 and microscopic changes, including microvascular hyaline thrombi, perivascular dermatitis, and eccrine gland necrosis. There was increased transcription of TBK1 and a reduction in transcription of TNFα by RT-qPCR in the COVID-19 group. IHC revealed reduced expression of ACE2, TLR7, and IL-6, and elevated expression of IFN-β by epidermal cells. In the dermis, there was decreased expression of STING, IFN-β, and TNF-α and increased expression of IL-6 in sweat glands. Our results highlight the role of type I IFN in the skin of COVID-19 patients, which may modulate the cutaneous response to SARS-CoV-2. Full article

Electrospinning techniques have been widely applied in diverse applications, such as biocompatible membranes, energy storage systems, and triboelectric nanogenerators (TENGs), with the capability to incorporate other functional materials to achieve specific purposes. Recently, gas sensors incorporating doped semiconducting materials fabricated by electrospinning have been extensively investigated. TENGs, functioning as self-powered energy sources, have been utilized to drive gas sensors without external power supplies. Herein, a self-powered triboelectric ethanol sensor (TEES) is fabricated by integrating a TENG and an ethanol gas sensor into a single device. The proposed TEES exhibits a significantly improved response time and lower detection limit compared to published integrated triboelectric sensors. The device achieves an open-circuit voltage of 51.24 V at 800 rpm and a maximum short-circuit current of 7.94 μA at 800 rpm. Owing to the non-contact freestanding operating mode, the TEES shows no significant degradation after 240,000 operational cycles. Compared with previous studies that integrated TENGs and ethanol sensors, the proposed TEES demonstrated a marked improvement in sensing performance, with a faster response time (6 s at 1000 ppm) and a lower limit of detection (10 ppm). Furthermore, ethanol detection is enabled by modulating the gate terminal of an IRF840 metal-oxide semiconductor field-effect transistor (MOSFET), which controls the illumination of a light-emitting diode (LED). The LED is extinguished when the electrical output decreases below the setting value, allowing for the discrimination of intoxicated states. These results suggest that the TEES provides a promising platform for self-powered, high-performance ethanol sensing. Full article

SARS-CoV-2 nonstructural protein (NSP) 6 is one of the factors affecting viral pathogenicity. Mutations in NSP6 continuously emerge during viral transmission and are closely associated with alterations in viral pathogenicity. This study investigated the structural and functional impacts of NSP6 mutations by analyzing NSP6 proteins from the Wuhan-Hu-1/B (WT) strain and predominant variants Alpha, XBB.1.16, BA.2.86, and JN.1 using bioinformatics, transcriptomics, and cellular experiments. The results demonstrate that the V3593F mutation decreased the β-sheet proportion and modified hydrogen bonding patterns, while the L3829F mutation enhanced structural stability by promoting random coils. The R3821K substitution exposed lysine residues, potentially enhancing molecular interactions. Combined transcriptomic profiling and functional assays revealed that WT-NSP6 significantly inhibited poly (I: C)-induced immune factor transcription and reduced the phosphorylation levels of p-IRF3 and p-STAT1, effects absent in the XBB.1.16 variant. Furthermore, WT-NSP6 markedly activated p-AKT and p-mTOR expression, with JN.1-NSP6 maintaining limited capacity to upregulate p-mTOR. However, p53 inhibitor treatment reversed Alpha-NSP6- and BA.2.86-NSP6-upregulated p-mTOR protein expression in cells. This study demonstrates that a high frequency of NSP6 mutations alters NSP6’s structure, impairing the type I interferon signaling pathway and affecting host antiviral responses through the p53-AKT-mTOR signaling pathway. These findings contribute to the understanding of evolution, immune evasion, and viral pathogenesis mechanisms, with potential implications for the development of antiviral therapies and preventive strategies for this viral infection. Full article

Due to the absence of gluten, rice noodles require complex processing to achieve a desirable texture. This study developed ethanolic-extruded indica rice flour (EERF) as a novel gluten substitute to simplify rice noodle production. EERF exhibited a distinct V-type crystalline structure (7.89% crystallinity) and high cold-paste viscosity (1043 cP), enabling its use as a binder in rice dough. When blended with native indica rice flour (IRF) at 10–20%, the EERF-IRF premix formed a cohesive dough with water via cold gelation, imparting viscoelasticity and tensile resistance. Optimal formulation (15% EERF for the premix and 37% water for making the dough) yielded fresh rice noodles with reduced cooking loss (5.57%) and a reduced breakage rate (14.44%), alongside enhanced sensory scores. This approach offers a clean-label, industrially scalable solution for producing rice noodles with simplified processing and improved quality. Full article

This study aimed to investigate the inhibitory effect of the chloroform fraction (CF) from Vitis vinifera root extract on LPS-induced neuroinflammation in BV-2 microglia cells and a C57/BL6J mouse model. CF significantly suppressed LPS-induced proinflammatory cytokines, including nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in BV-2 microglia cells. Mechanistically, CF inhibited LPS-induced activation of nuclear factor-κB (NF-κB) by blocking the p65 subunit and preventing the phosphorylation of NF-kappa-B inhibitor α (IκBα), while its effect was independent of the mitogen-activated protein kinase (MAPK) pathway. Furthermore, CF modulated the TRIF signaling pathway by regulating TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3), which contributed to the suppression of inflammatory mediators in BV-2 microglia cells. In vivo, we evaluated the neuroprotective effects of CF against cognitive dysfunction and inflammatory responses in an LPS-induced mouse model. Our behavioral assessments, including the Morris water maze and Y-maze tests, demonstrated that CF alleviated LPS-induced spatial learning impairment and cognitive decline. Additionally, CF significantly reduced the levels of inflammatory cytokines in serum and inflammatory mediators proteins expression in whole brain in LPS-injected mice, suggesting a direct link between reduced inflammatory responses and improved cognitive function. These findings suggest that CF from V. vinifera root extract may serve as a potential therapeutic strategy for neurodegenerative diseases mediated by microglial activation, such as Alzheimer’s disease. Full article

Since the onset of the COVID-19 pandemic, various severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants have emerged. Although the primary site of SARS-CoV-2 infection is the lungs, it can also affect the brain and induce neurological symptoms. However, the specific effects of different variants on the brain remain unclear. In this study, a whole-transcriptome analysis was conducted using the brain tissues of K18-hACE2 mice infected with the ancestral B.1 (Wuhan) variant and with major SARS-CoV-2 variants of concern, including B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617.2 (Delta) and B.1.529 (Omicron). After sequencing, differential gene expression, gene ontology (GO) and genome pathway enrichment analyses were performed. An Immune Cell Abundance Identifier (ImmuCellAI) was used to identify the abundance of different cell populations. Additionally, RT-qPCR was used to validate the RNA-seq data. The viral load and hierarchical clustering analyses divided the samples into two different clusters with notable differences in gene expression at day 6 post-infection for all variants compared to the control group. GO and the Kyoto Encyclopedia of genes and genomes enrichment analyses revealed similar patterns of pathway enrichment for different variants. ImmuCellAI revealed the changes in immune cell populations, including the decrease in CD4⁺ T and B cell proportions and the increase in CD8⁺ T and dendritic cell proportions. A co-expression network analysis revealed that some genes, such as STAT1, interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α), were dysregulated in all variants. A RT-qPCR analysis for IL-6, CXCL10 and IRF7 further validated the RNA-seq analysis. In conclusion, this study provides, for the first time, an extensive transcriptome analysis of a K18-hACE2 mouse brain after infection with major SARS-CoV-2 variants. Full article

TNF and IFN-γ are key proinflammatory cytokines implicated in the pathophysiology of COVID-19. Toll-like receptor (TLR)7 and TLR8 are known to recognize SARS-CoV-2 and induce TNF and IFN-γ production. However, it is unclear whether TNF and IFN-γ levels are altered through TLR-dependent pathways and whether these pathways mediate disease severity during COVID-19. This study aimed to investigate the association between TNF/IFN-γ levels and immune cell activation to understand their role in disease severity better. We enrolled 150 COVID-19 patients, who were classified by their systemic TNF and IFN-γ levels (high (H) or normal–low (N-L)) as TNF^HIFNγ^H, TNF^HIFNγ^N-L, TNF^N-LIFNγ^H, and TNF^N-LIFNγ^N-L. Compared to patients with TNF^N-LIFNγ^N-L, patients with TNF^HIFNγ^H had high systemic levels of pro- and anti-inflammatory cytokines and cytotoxic molecules, and their T cells and monocytes expressed TNF receptor 1 (TNFR1). Patients with TNF^HIFNγ^H presented the SNP rs3853839 to TLR7 and increased levels of MYD88, NFκB, and IRF7 (TLR signaling), FADD, and TRADD (TNFR1 signaling). Moreover, critical patients were observed in the four COVID-19 groups, but patients with TNF^HIFNγ^H or TNF^HIFNγ^N-L most required invasive mechanical ventilation. We concluded that increased TNF/IFN-γ levels are associated with hyperactive immune cells, whereas normal/low levels are associated with hypoactivity, suggesting a model to explain that the pathophysiology of critical COVID-19 may be mediated through different pathways depending on TNF and IFN-γ levels. These findings highlight the potential for exploring the modulation of TNF and IFN-γ as a therapeutic strategy in severe COVID-19. Full article

The first marine pestivirus, Phocoena pestivirus (PhoPeV), isolated from harbor porpoise, has been recently described. To further characterize this unique pestivirus, its host cell tropism and growth kinetics were determined in different cell lines. In addition, the interaction of PhoPeV with innate immunity in porcine epithelial cells and the role of selected cellular factors involved in the viral entry and RNA replication of PhoPeV were investigated in comparison to closely and distantly related pestiviruses. While Bungowannah pestivirus (BuPV), a unique porcine pestivirus closely related to PhoPeV, exhibits a broad cell tropism, PhoPeV only infects cells from pigs, cattle, sheep, and cats, as has been described for classical swine fever virus (CSFV). Viral titers correlate with the amount of intracellular PhoPeV-specific RNA detected in the tested cell lines. PhoPeV replicates most efficiently in the porcine kidney cell line SK6. Pestiviruses generally counteract the cellular innate immune response by degradation of interferon regulatory factor 3 (IRF3) mediated by the viral N-terminal protease (N^pro). No degradation of IRF3 and an increased expression of the type 1 interferon-stimulated antiviral protein Mx1 was observed in porcine cells infected with PhoPeV whose genome lacks the N^pro encoding region. Infection of a CD46-deficient porcine cell line suggested that CD46, which is implicated in the viral entry of several pestiviruses, is not a major factor for the viral entry of PhoPeV. Moreover, the results of this study confirmed that the cellular factor DNAJC14 plays a crucial role in viral RNA replication of non-cytopathic pestiviruses, including PhoPeV. Full article

Background/Objectives: COVID-19 is characterised by a wide variety of clinical manifestations, and clinical tests and genetic analysis might help to predict patient outcomes. Methods: In the current study, the expression of genes related to immune response (CCL5, IFI6, OAS1, IRF9, IL1B, and TGFB1) was analysed in the upper airway and paired-blood samples from 25 subjects infected with SARS-CoV-2. Relative gene expression was determined by RT-qPCR. Results: CCL5 expression was higher in the blood than in the upper airway (p < 0.001). In addition, a negative correlation was found between IFI6 and viral load (p = 0.033) in the upper airway, suggesting that the IFI6 expression inhibits the viral infection. Concerning sex, women expressed IL1B and IRF9 in a higher proportion than men at a systemic level (p = 0.008 and p = 0.049, respectively). However, an increased expression of IRF9 was found in men compared to women in the upper airway (p = 0.046), which could be due to the protective effect of IRF9, especially in men. Conclusions: The higher expression of CCL5 in blood might be due to the key role of this gene in the migration and recruitment of immune cells from the systemic circulation to the lungs. Our findings confirm the existence of sex differences in the immune response to early stages of the infection. Further studies in a larger cohort are necessary to corroborate the current findings. Full article

African swine fever (ASF), a highly infectious and devastating disease affecting both domestic pigs and wild boars, is caused by the African swine fever virus (ASFV). ASF has resulted in rapid global spread of the disease, leading to significant economic losses within the swine industry. A significant obstacle to the creation of safe and effective ASF vaccines is the existing knowledge gap regarding the pathogenesis of ASFV and its mechanisms of immune evasion. The cyclic GMP–AMP synthase (cGAS)–stimulator of interferon genes (STING) pathway is a major pathway mediating type I interferon (IFN) antiviral immune response against infections by diverse classes of pathogens that contain DNA or generate DNA in their life cycles. To evade the host’s innate immune response, ASFV encodes many proteins that inhibit the production of type I IFN by antagonizing the cGAS-STING signaling pathway. Multiple proteins of ASFV are involved in promoting viral replication by protein–protein interaction during ASFV infection. The protein QP383R could impair the function of cGAS. The proteins EP364R, C129R and B175L could disturb the function of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP). The proteins E248R, L83L, MGF505-11L, MGF505-7R, H240R, CD2v, E184L, B175L and p17 could interfere with the function of STING. The proteins MGF360-11L, MGF505-7R, I215L, DP96R, A151R and S273R could affect the function of TANK Binding Kinase 1 (TBK1) and IκB kinase ε (IKKε). The proteins MGF360-14L, M1249L, E120R, S273R, D129L, E301R, DP96R, MGF505-7R and I226R could inhibit the function of Interferon Regulatory Factor 3 (IRF3). The proteins MGF360-12L, MGF505-7R/A528R, UBCv1 and A238L could inhibit the function of nuclear factor kappa B (NF-Κb). Full article

Background: Diabetic macular edema (DME) causes vision impairment and significant vision loss. Portable optical coherence tomography (OCT) has the potential to enhance the accessibility and frequency of DME screening, facilitating early diagnosis and continuous monitoring. This study aimed to evaluate the reliability of a portable OCT device (ACT100) in assessing DME compared with a traditional stationary OCT device (Cirrus 5000 HD-OCT plus). Methods: This prospective clinical investigation included 40 eyes of 33 patients with DME. Participants with significant refractive errors (myopia > −6.0 diopters or hyperopia > +3.0 diopters), vitreous hemorrhage, tractional retinal detachment, or other ocular diseases affecting imaging were excluded. Spectral-domain OCT was performed by a single examiner using both devices to capture macular volume scans under mydriasis. Central macular thickness (CMT) was evaluated using the analysis software for each device: Cirrus used version 6.0.4, and ACT100 used version V20. We analyzed inter-evaluator and inter-instrument agreements for qualitative assessments of the intraretinal fluid (IRF), subretinal fluid (SRF), and epiretinal membrane (ERM) using Cohen’s kappa coefficient, whereas quantitative CMT assessments were correlated using Spearman’s correlation coefficient. Results: Substantial inter-evaluator agreement for IRF/SRF (κ = 0.801) and ERM (κ = 0.688) with ACT100 and inter-instrument agreement (κ = 0.756 for IRF/SRF, κ = 0.684 for ERM) were observed. CMT values measured using ACT100 were on average 29.6 μm lower than that of Cirrus (285.8 ± 56.6 vs. 315.4 ± 84.7 μm, p < 0.0001) but showed a strong correlation (R = 0.76, p < 0.0001). Conclusions: ACT100 portable OCT demonstrated high reliability for DME evaluations, comparable to that of stationary systems. Full article

The integrated stress response, especially stress granules (SGs), contributes to host immunity. Typical G3BP1⁺ stress granules (tSGs) are usually formed after virus infection to restrain viral replication and stimulate innate immunity. Recently, several SG-like foci or atypical SGs (aSGs) with proviral function have been found during viral infection. We have shown that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) protein induces atypical N⁺/G3BP1⁺ foci (N⁺foci), leading to the inhibition of host immunity and facilitation of viral infection. However, the precise mechanism has not been well clarified yet. In this study, we showed that the SARS-CoV-2 N (SARS2-N) protein inhibits dsRNA-induced growth arrest and DNA damage-inducible 34 (GADD34) expression. Mechanistically, the SARS2-N protein promotes the interaction between GADD34 mRNA and G3BP1, sequestering GADD34 mRNA into the N⁺foci. Importantly, we found that GADD34 participates in IRF3 nuclear translocation through its KVRF motif and promotes the transcription of downstream interferon genes. The suppression of GADD34 expression by the SARS2-N protein impairs the nuclear localization of IRF3 and compromises the host’s innate immune response, which facilitates viral replication. Taking these findings together, our study revealed a novel mechanism by which the SARS2-N protein antagonized the GADD34-mediated innate immune pathway via induction of N⁺foci. We think this is a critical strategy for viral pathogenesis and has potential therapeutic implications. Full article

The pathophysiological mechanisms of the post-acute sequelae of COVID-19 (PASC) remain unclear. Sex differences not only exist in the disease severity of acute SARS-CoV-2 infection but also in the risk of suffering from PASC. Women have a higher risk of suffering from PASC and a longer time to resolution than men. To explore the possible immune mechanisms of PASC among non-elderly females, we mined single-cell transcriptome data from peripheral blood samples of non-elderly female patients with PASC and acute SARS-CoV-2 infection, together with age- and gender-matched non-PASC and healthy controls available from the Gene Expression Omnibus database. By comparing the differences, we found that a CD14⁺ monocyte subset characterized by higher expression of signal transducers and activators of transcription 2 (STAT2) (CD14⁺STAT2^high) was notably increased in the PASC patients compared with the non-PASC individuals. The transcriptional factor (TF) activity analysis revealed that STAT2 and IRF9 were the key TFs determining the function of CD14⁺STAT2^high monocytes. STAT2 and IRF9 are TFs exclusively involving type I and III interferon (IFN) signaling pathways, resulting in uncontrolled IFN-I signaling activation and type I interferonopathy. Furthermore, increased expression of common interferon-stimulated genes (ISGs) has also been identified in most monocyte subsets among the non-elderly female PASC patients, including IFI6, IFITM3, IFI44L, IFI44, EPSTI1, ISG15, and MX1. This study reveals a featured CD14⁺STAT2^high monocyte associated with uncontrolled IFN-I signaling activation, which is indicative of a possible type I interferonopathy in the non-elderly female patients with PASC. Full article