Search Results (508)

African swine fever (ASF) is a highly lethal viral disease of pigs caused by the African swine fever virus (ASFV). The mortality rate is nearly 100%. Currently, it is known that the ASFV has a complex structure, and its genome encodes various immune escape proteins. However, the pathogenic mechanism of ASFV remains to be studied. This study found that ASFV pD345L significantly inhibits the activation of the ISRE promoter triggered by interferon (IFN) β and the production of downstream IFN-stimulated genes (ISG). We further reveal that pD345L may degrade STAT1 via the autophagy pathway and impede its nuclear translocation; this inhibitory effect is closely associated with its exonuclease activity. Our research results have clarified the impact of ASFV pD345L on the JAK/STAT signaling pathway, expanding our understanding of the inhibitory effect of ASFV-encoded proteins on the host’s innate immunity, and to some extent, contributing to the development of an African swine fever vaccine. Full article

The role of human leukocyte antigen F (HLA-F) at the maternal–fetal interface (MFI) during viral infection and its regulation by interferon signaling remains poorly understood. Here, we investigated HLA-F expression and regulation in first-trimester trophoblast cells following activation of the type I interferon pathway and viral infection. We demonstrate that HLA-F is significantly upregulated at both mRNA and protein levels in response to Poly(I:C) and IFN-β in a dose- and time-dependent manner, suggesting its regulation as an interferon-stimulated gene (ISG). Zika virus (ZIKV) infection similarly induced HLA-F upregulation over time. In contrast, HSV-2 infection downregulated HLA-F mRNA while maintaining steady protein levels, indicative of virus-specific regulatory mechanisms. Moreover, we identified a soluble form of HLA-F secreted following Poly(I:C) stimulation. These findings reveal that HLA-F is dynamically regulated in trophoblasts during viral challenge and type I IFN signaling activation, supporting its broader immunomodulatory role in antiviral defense and immune tolerance at the MFI. Full article

Interferons (IFNs) play fundamental roles in cancer immunity. We have previously shown that conditional ablation of Notch pathway genes in a mouse model of glioma results in impaired IFNγ signaling and immunosuppressive tumors. However, it remained unclear whether the interaction between the Notch and IFN signaling pathways could be leveraged to counteract immune evasion in glioma. Here, we investigated whether expression of the intrinsically active Notch intracellular domain (NICD) could enhance IFN responses in glioma cells. Using a doxycycline (Dox)-inducible system, we overexpressed (OE) NICD in U-251MG human glioma cells. NICD-OE dramatically potentiated STAT1 phosphorylation in response to stimulation with either IFNγ or IFNα. Moreover, NICD-OE induced the expression of the transcription factor IRF1, a regulator of IFN signaling responses. Notably, NICD-OE in U-251MG human glioma cells boosted the IFNγ-dependent transcription of the CXCL9 and CXCL10 genes, which encode cytokines that regulate T cell function. Accordingly, NICD-OE in vivo promoted cytotoxic T lymphocyte recruitment to the tumor and reduced tumor cell proliferation in a murine glioma model. Hence, we have identified a signaling network that could be exploited to enhance anti-tumor immunity in glioma subtypes. Full article

This study is a narrative review of natural killer (NK) cells in Behcet disease (BD). BD is an inflammatory disorder with manifestations in mucosal tissues. Unlike autoimmune diseases that generate autoantibodies, BD is believed to be an autoinflammatory disease triggered by innate immune cells rather than adaptive cells. Hyperactivation of neutrophils causes vasculitis and thrombosis, and they migrate into cutaneous and ocular lesions. Dominance of M1 macrophages promotes the differentiation of Th1 cells. Moreover, the cross-reaction of bacterial heat shock proteins induces production of cytokines such as IL-4 and IFN-γ in γδT cells, which alters the balance between Th1 and Th2 phenotypes. Nevertheless, NK cells play more critical roles in BD pathogenesis than other innate immune cells because not only is their activity precisely controlled by the interaction between ligands and receptors, but NK1 shift also elicits Th1 dominance. The genetic factors associated with BD are HLA-B51 and major histocompatibility complex class I-related chain A (MICA), which stimulate NK receptors as ligands. Improperly processed peptides dysregulate their interaction with NK receptors, triggering the inflammatory response. NK1 and NK2 subsets represent cytokine production in relapse and remission periods; however, the cytotoxicity of NK cells in relapse is lower than that in remission periods. It still remains unclear how NK cells are activated recurrently and expand cytokine production. This review highlights the regulation of gene expression encoding NK receptors, tissue-resident NK cells, and adaptive NK cells to discuss their potential for relapse. Splicing variants and readthrough genes encoding NK receptors easily alter cytokine production. Moreover, tissue-resident NK cells in mucosal tissues and adaptive NK cells that memorize the virus infection have the potential to trigger hyperactivation in relapse. Full article

African swine fever virus (ASFV) is the causative agent of African swine fever (ASF), a fatal and highly contagious disease, resulting in enormous losses to the global swine industry. No licensed vaccines or effective therapeutics are currently available to control ASFV infection. Interferons (IFNs) serve as key mediators of host antiviral immunity by inducing interferon-stimulated genes (ISGs), but the specific mechanisms by which individual ISGs restrict ASFV replication remain unclear. Interferon-induced protein with tetratricopeptide repeats 3 (IFIT3, also called ISG60) has been shown to exhibit antiviral activity against various viruses, but its role in ASFV infection has not been previously studied. Here, we used porcine alveolar macrophages (PAMs), the primary target cells of ASFV, to investigate IFIT3’s function in ASFV replication. We found that overexpression of IFIT3 inhibited ASFV replication, while its knockdown enhanced viral propagation. Mechanistically, IFIT3 directly blocked ASFV adsorption to host cells, thereby suppressing all subsequent stages of the viral cycle. IFIT3 also specifically interacted with ASFV F334L, an early viral gene product that encodes the small subunit of ribonucleotide reductase, a key enzyme for viral DNA synthesis. Additionally, IFIT3 positively regulated the STAT1/TBK1/IRF3 signaling axis: its overexpression increased phosphorylation of TBK1 and IRF3, as well as the protein level of STAT1, while IFIT3 knockdown attenuated activation of these molecules. Transcriptomic analysis of IFIT3-knockout PAMs revealed significant suppression of innate immune pathways, including type I interferon, JAK-STAT, and RIG-I-like receptor pathways, along with downregulated expression of core antiviral molecules such as ISG15, MX1, and STAT1. Conversely, pathways related to viral adsorption, endocytosis, and cytoskeleton were activated, and pathways involved in protein translation initiation, endoplasmic reticulum stress, and autophagy were dysregulated, creating a favorable intracellular environment for ASFV replication. In conclusion, IFIT3 restricts ASFV replication possibly by inhibiting viral adsorption and promoting innate immune signaling, identifying it as a potential therapeutic target against ASFV. This study’s limitation is its in vitro PAM model; future work will validate IFIT3’s role in vivo and develop targeted inhibitors. Full article

Background: E2 is fundamental to the onset and progression of CC. CAFs are the most abundant stromal population in the tumor microenvironment. CAFs have been shown to promote protumoral effects in CC cell lines; however, the effects of E2-stimulated CAFs remain to be explored. Objectives: This study aimed to evaluate whether E2-stimulated CAFs modify the behavior of SiHa and HeLa tumor cells, including their metabolism, ROS production, migration, apoptosis, and gene expression. Methods: Characterization and estrogen receptor expression in primary CAF cultures were evaluated by immunofluorescence. Supernatants from non-stimulated and E2-stimulated CAFs were used to culture CC cells, and mitochondrial metabolism was measured by MTT, ROS production by H2DCFDA, migration using the wound-healing assay, apoptosis by Annexin V assay, and gene expression by next-generation RNA-seq. Results: Stimulation of CC cells with CAFs’ supernatants demonstrated that it influences tumor cells in different ways. In SiHa cells, the metabolic shift was supported by decreased mitochondrial metabolism, increased ROS production, and enhanced gene enrichment for glycolysis and hypoxia responses. On the other hand, in HeLa cells, CAFs enhanced migration and gene enrichment in KRAS signaling, epithelial-mesenchymal transition, and the proinflammatory response, via enrichment of the IL6/JAK/STAT3 signaling pathway, along with the overexpression of cytokines such as IFN-γ, IL-6, and IL-8. Conclusions: CAFs exert protumoral effects by promoting a metabolic shift in SiHa cells or enhancing migration and cytokine secretion in HeLa cells; these effects are independent of E2 stimulation in CAFs. Full article

Phosphatidylinositol-3-kinases (PI3Ks) are heterodimers of catalytic and regulatory subunits that regulate cell metabolism, activation, and survival. PI3K, particularly the p110α catalytic isoform, is frequently mutated in cancer, and highly specific inhibitors such as alpelisib are currently used in oncology and in PIK3CA-related overgrowth disorders. Given the relevance of macrophages in anti-tumor immunity, we examined the impact of alpelisib on murine monocytes’ intracellular signaling and on in vitro differentiation, polarization, and effector functions of macrophages. Real-time qPCR (RT-qPCR) showed comparable relative expression of PI3K isoforms (p110α, p110β, p110δ, p110γ and p85) in bone marrow monocytes and in macrophages differentiated with macrophage colony-stimulating factor (M-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF). However, alpelisib increased p110α, p110β, and p85 relative gene expression (2–3-fold) during M-CSF-dependent differentiation. Functionally, alpelisib-treated M-CSF macrophages displayed enhanced interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α) secretion and reduced IL-10 production after lipopolysaccharide (LPS) plus interferon gamma (IFN-γ) or LPS stimulation. In contrast, GM-CSF macrophages differentiated with alpelisib secreted lower levels of IL-6 and TNF-α and reduced inducible nitric oxide synthase (iNOS) and arginase-1 (Arg-1) gene expression. Additionally, cytokine profiles (IL-2, IL-6, IFN-γ and IL-10) were altered when alpelisib-treated macrophages were cocultured with CD4⁺ T cells under either antigen-specific or polyclonal activation conditions, indicating that the inhibitor modifies both differentiation and subsequent effector interactions of the macrophages. Thus, alpelisib induces lasting effects on macrophage differentiation and function, with potential implications in tumor-associated macrophages that develop under M-CSF or GM-CSF-rich cancer microenvironments. Full article

The rising health threat to healthcare workers (HCWs) demands innovative preventive solutions that are affordable, scalable, and easy to deploy, especially in resource-limited settings. This present study investigated the effects of Lactococcus lactis strain Plasma (LC-Plasma) intake on upper respiratory infection (URI)-like symptoms in a healthy healthcare-associated population in Vietnam. A randomized, placebo-controlled, double-blind, parallel-group clinical trial was conducted, integrating clinical symptom analysis with ex vivo immune response analysis of peripheral blood mononuclear cells (PBMCs). The study found that after 4 weeks of continuous oral LC-Plasma intake, participants in the LC-Plasma group had significantly fewer cumulative days of fever and fatigue than those in the Control group. Increased expression of interferon-stimulated genes (ISGs), particularly MxA, was observed in PBMC cultures from the LC-Plasma intake group. In PBMCs from LC-Plasma recipients classified as low IFN-α responders, the addition of CpG ODN 2216, a mild TLR9 agonist, significantly enhanced interferon-α production. Humoral factors derived from LC-Plasma-primed PBMCs demonstrated inhibitory effects on dengue virus replication in Huh-7 cells. These results suggest that LC-Plasma consumption by the healthcare-associated population reduces the severity of viral infection symptoms, notably fever and fatigue. Elevation of systemic antiviral immunity through activation of plasmacytoid dendritic cells (pDCs) to produce IFN-α and upregulation of ISG expression could be the mechanisms of action. Lactococcus lactis LC-Plasma supplementation, hence, presents a promising adjunctive approach to alleviate the burden of URI-like symptoms in low-resourced vulnerable populations. Full article

Skin aging is driven by both intrinsic and extrinsic factors, including ultraviolet (UV) radiation and environmental stressors. Tumor necrosis factor-alpha (TNF-α) is a key pro-aging cytokine that promotes reactive oxygen species (ROS) production, leading to collagen degradation and inflammatory responses in skin cells. In this study, we investigated the protective effects of Prunus persica flower extract and its major constituents (1–4) against TNF-α–induced oxidative and inflammatory responses in human dermal fibroblasts (HDFs) and human epidermal keratinocytes (HEKs). In HDFs, the extract and isolated compounds significantly suppressed TNF-α–induced ROS generation and matrix metalloproteinase-1 (MMP-1) secretion while enhancing collagen synthesis. Notably, mandelamide (4) markedly reduced MMP-1 secretion (from 7.53 ± 0.28 to 2.97 ± 0.12, p < 0.001) and restored collagen levels (from 3.3 ± 0.03 to 19.1 ± 0.58, p < 0.001). In HEKs, mandelamide attenuated the production of inflammatory mediators under TNF-α stimulation and further suppressed MMP expression while restoring the mRNA expression of hyaluronan synthase genes under TNF-α/ interferon-γ (IFN-γ) co-stimulation. Importantly, mandelamide exhibited selective activity under inflammatory conditions without affecting basal cellular states. Collectively, these findings demonstrate that mandelamide is a key bioactive constituent of Prunus persica (P. persica) flowers and exerts protective effects against inflammation-associated skin aging through the modulation of oxidative stress and extracellular matrix homeostasis. Full article

Crimean–Congo hemorrhagic fever virus (CCHFV) and severe fever with thrombocytopenia syndrome virus (SFTSV) are tick-borne pathogens that cause severe illness and high mortality. Early diagnosis is critical, particularly in resource-limited settings, to enable timely intervention. Host gene expression profiling offers a promising approach to identify potential biomarkers for early detection, disease staging, and logical treatment decision-making. Using a transient IFN-α/β receptor-suppressed mouse model, we performed targeted transcriptomic analysis on blood samples collected at 2, 3, and 4 days after CCHFV or SFTSV challenge. A significant increase in viral load and changes in gene expression were observed as early as two days post-challenge. CCHFV induced a progressively evolving interferon-driven response, while SFTSV triggered rapid, sustained immune activation. Affected targets included interferon-stimulated genes, chemokines, cytokines, Toll-like receptors, and genes associated with viral evasion and innate immune response. Despite shared expression patterns, unique genes were identified as potential biomarkers to distinguish between CCHFV and SFTSV infections. Differential gene expression revealed distinct immune response dynamics, with suppression of critical immune regulatory genes suggesting transcriptional signatures associated with viral evasion mechanisms contributing to disease severity. These findings provide a comparative analysis of molecular pathways and gene expression changes, offering critical insights for biomarker discovery, effective triage, and evaluation of appropriate medical intervention. Full article

Chikungunya virus (CHIKV) is an alphavirus that infects dermal fibroblasts as a primary target cell during natural mosquito-borne transmission. While primary human dermal fibroblasts (hDFs) have been implicated as a key source of type I interferon (IFN-I) during CHIKV infection, the dynamics of this response and its sufficiency for antiviral protection remain incompletely understood. Here, we systematically characterize in vitro CHIKV infection of primary hDFs, evaluating the effects of single-passage viral stock origin (mammalian- vs. mosquito-propagated), donor variability, and multiplicity of infection (MOI) on infection kinetics and innate immune induction. We demonstrate that hDFs support high-titered CHIKV replication at both MOI 1 and 0.01, resulting in universal cell death by 72 hpi despite robust IFNβ transcript induction—reaching up to ~2800-fold over mock—and secretion of pro-inflammatory cytokines, including IFNα2, TNFα, IL-1β, and IL-8. Notably, IFNβ protein levels remained below 10 pg/mL under all infection conditions, revealing a disconnect between transcriptional and translational responses, suggesting CHIKV-mediated translational suppression. Pharmacological inhibition of TBK1/IKKε via amlexanox did not suppress IFNβ transcript induction at any tested concentration, suggesting that canonical PRR signaling through this node—including both RIG-I/MAVS and TLR3/TRIF pathways—is not the major driver of the observed transcriptional response. In contrast, co-inoculation with exogenous IFNβ as low as 20 pg/mL activated IFNAR signaling, robustly upregulated interferon-stimulated genes (ISGs), and fully rescued hDFs from otherwise lethal infection. Together, these findings demonstrate that CHIKV-infected hDFs mount a transcriptionally robust but translationally insufficient innate immune response and that the transcriptional response appears to operate independently of TBK1/IKKε. These results have direct implications for understanding how the skin microenvironment may modulate early CHIKV pathogenesis and suggest that paracrine IFNβ signaling from neighboring cell types may be critical for fibroblast survival during natural infection. Full article

Background/Objectives: SARS-CoV-2 is the causative agent of COVID-19, an infectious viral respiratory disease with human-to-human transmission. Current molecular understanding of how hosts respond to infection by respiratory viral pathogens in general and to SARS-CoV-2 in particular is still a research field under development. The activation levels of various host pathways are dependent on several variables, including the host tissue compartment. Methods: In this work, Illumina RNA sequencing was performed to assess the transcriptional host response to SARS-CoV-2 infection using COVID-19 PCR testing nasopharyngeal (NP) swab remnants from twenty infected and nine non-infected individuals. Results: Differential gene expression (DGE) analysis identified 182 overexpressed genes, with strong enrichment in innate immune and viral response genes. This included a significant induction of IFIH1/MDA5, a pattern recognition receptor (PRR) gene participating in the initial sensing of viral RNAs and subsequent cascade activation of interferon (IFN) and IFN-stimulated genes (ISGs). Interestingly, we observed different levels of concordance with previous similar studies and a significant induction of RIG1 and TLR3, two PRR genes encoding proteins that function to upregulate IFN and ISGs, but which are not normally identified as differentially expressed genes (DEGs). Finally, the overexpression of MX1, a well-characterized biomarker of viral infection; IFIT1, one of the top upregulated genes; and OAS1, OAS2 and OAS3, genes with a molecular function, 2-5-oligoadenylate synthase activity, identified as enriched in the DGE analyses, was confirmed by RT-qPCR. Conclusions: This study provides insights into upper respiratory tract responses to SARS-CoV-2 infections and identifies a set of differentially expressed genes (DEGs) with potential as candidates for further investigations as viral infection biomarkers. Full article

Manganese ions (Mn²⁺) are an essential trace element within organisms spanning the entire tree of life. It has reported that Mn²⁺ exerts strong immunocompetence effects and exhibits antiviral effects against various human and animal viruses, including DNA and RNA viruses. Recently, Mn²⁺ has been found to be involved in the activation of the innate immune DNA-sensing cyclic GMP-AMP synthase (cGAS) stimulator of interferon genes (STING) pathway and subsequent antiviral function. However, the antiviral mechanism of Mn²⁺ remains unclear. In the current study, the results suggest that the cGAS-STING pathway is essential for Mn²⁺ to promote interferon (IFN) signaling, but it is not essential for triggering antiviral functions. After knocking out the STING or interferon regulatory factor 3 (IRF3) gene, Mn²⁺ still retains its antiviral activity against herpes simplex virus type 1 (HSV-1) and vesicular stomatitis virus (VSV). Furthermore, the results from transcriptomic analysis indicate that Mn²⁺ can induce a significant change in the apoptotic process in STING⁻/⁻ 3D4/21 cells. Mn²⁺ can induce cell apoptosis through the oxidative stress pathway, and inhibiting the apoptotic signal could suppress Mn²⁺-mediated antiviral activity in STING⁻/⁻ 3D4/21 cells. Additionally, dual knockout of IRF3 and caspase3, resulting in concurrent loss of IFN and apoptotic signals, eliminates the antiviral effects of Mn²⁺. In summary, the current study suggests that Mn²⁺ could exert antiviral effects not only through the cGAS-STING-IFN pathway but also via the reactive oxygen species (ROS)-apoptosis pathway. Full article

Orf virus (ORFV) is a globally distributed zoonotic parapoxvirus that causes a highly contagious mucocutaneous disease in small ruminants. Despite the urgent demand for vaccination-based control, no licensed vaccines are currently available universally. In this study, we generated two recombinant Sendai virus (SeV) vectors expressing ORFV 011 (rSeV-GFP-B2L) and ORFV 059 (rSeV-GFP-059) genes and evaluated their ability to stimulate antiviral responses in vitro. Following the transduction, we assessed transgene expression, innate immune activation, induction of interferon-stimulated genes (A3Z1, OBST2, SAMHD1), and antiviral activity. Both vectors significantly upregulated pattern recognition receptors (TLRs, RIG-I) and type I interferon (IFN-β) genes, with rSeV-GFP-059 inducing the strongest response. Remarkably, OBST2 was robustly upregulated, suggesting a potential role in restricting ORFV replication. Antiviral activity assays revealed a marked reduction in ORFV DNA copies and a mild decrease in ORFV RNA transcription in rSeV-GFP-059-transduced cells, particularly at later time points, accompanied by complete abrogation of the typical cytopathic effect. Collectively, these results demonstrate that SeV-based vectors, particularly rSeV-GFP-059, efficiently prime antiviral immunity and suppress ORFV replication, establishing a promising platform for further in vivo vaccine evaluation in sheep. Full article

Viral infections remain a global public health challenge. Stimulating the innate immune system is a potent therapeutic strategy that promotes pathogen clearance, directly impacting disease severity and clinical outcomes. Interferons and interferon-stimulated genes (ISGs) are critical components of this antiviral defense system. Neomycin, an aminoglycoside antibiotic, can induce ISG expression and help establish an antiviral state. In this study, we demonstrated that neomycin induces the production of pro-inflammatory cytokines (IL1β, TNFα, IL6, GM-CSF, and IFN-γ) in peripheral mononuclear blood cells (PBMCs) and activates key antiviral ISGs, including MxA, OAS1, and IRF7. The protein expression profiles elicited by neomycin were comparable to those induced by poly(I:C). Intranasal delivery of neomycin to CBA and BALB/c mice induced various ISGs in both the respiratory tract and splenic tissues. Prophylactic administration of neomycin significantly inhibited influenza B virus replication in the lung and nasal turbinates of CBA mice in a sublethal infection model. Overall, our data suggest that neomycin, when used prophylactically alone or combined with other antiviral strategies, shows considerable potential for the attenuation of influenza B virus infections. Full article