Seneca Valley virus 3Cpro antagonizes type I interferon response by targeting STAT1-STAT2-IRF9 and KPNA1 signals.

IMPORTANCE: Type I interferon (IFN) signaling plays a principal role in host innate immune responses against invading viruses. Viruses have evolved diverse mechanisms that target the Janus kinase-signal transducer and activator of transcription (STAT) signaling pathway to modulate IFN response negatively. Seneca Valley virus (SVV), an emerging porcine picornavirus, has received great interest recently because it poses a great threat to the global pork industry. However, the molecular mechanism by which SVV evades host innate immunity remains incompletely clear. Our results revealed that SVV proteinase (3Cpro) antagonizes IFN signaling by degrading STAT1, STAT2, and IRF9, and cleaving STAT2 to escape host immunity. SVV 3Cpro also degrades karyopherin 1 to block IFN-stimulated gene factor 3 nuclear translocation. Our results reveal a novel molecular mechanism by which SVV 3Cpro antagonizes the type I IFN response pathway by targeting STAT1-STAT2-IRF9 and karyopherin α1 signals, which has important implications for our understanding of SVV-evaded host innate immune responses.

Fast detection of hypobromous acid in cells and the water environment using a lysosome-targeted fluorescent probe.

A new fluorescent probe SWJT-23 with lysosomal targeting ability for detection of hypobromous acid (HBrO) was synthesised based on the naphthalimide skeleton. This probe exhibited a fast response (within 3s), a low detection limit (1.24 nM), excellent selectivity and a high fluorescence quantum yield (Φ = 0.490). Moreover, SWJT-23 not only realized the sensitive detection of HBrO in cells and water samples, but also was fabricated as a paper-based sensor. In consequence, SWJT-23 is expected to be an efficient and powerful tool for monitoring HBrO in organisms and the environment in realistic scenarios.

Synergetic Contributions of Viral VP1, VP3, and 3C to Activation of the AKT-AMPK-MAPK-MTOR Signaling Pathway for Seneca Valley Virus-Induced Autophagy.

Seneca Valley virus (SVV), a member of the Picornaviridae family, can activate autophagy via the PERK and ATF6 unfolded protein response pathways and facilitate viral replication; however, the precise molecular mechanism that regulates SVV-induced autophagy remains unclear. Here, we revealed that SVV infection inhibited the phosphorylation of mechanistic target of rapamycin kinase (MTOR) and activated phosphorylation of the serine/threonine kinase AKT. We observed that activating AMP-activated protein kinase (AMPK), extracellular signal-regulated kinase (ERK), mitogen-activated protein kinase (MAPK), and p38 MAPK signaling by SVV infection promoted autophagy induction and viral replication; additionally, the SVV-induced autophagy was independent of the ULK1 complex. We further evaluated the role of viral protein(s) in the AKT-AMPK-MAPK-MTOR pathway during SVV-induced autophagy and found that VP1 induced autophagy, as evidenced by puncta colocalization with microtubule-associated protein 1 light chain 3 (LC3) in the cytoplasm and enhanced LC3-II levels. This might be associated with the interaction of VP1 with sequestosome 1 and promoting its degradation. In addition, the expression of VP1 enhanced AKT phosphorylation and AMPK phosphorylation, while MTOR phosphorylation was inhibited. These results indicate that VP1 induces autophagy by the AKT-AMPK-MTOR pathway. Additionally, expression of VP3 and 3C was found to activate autophagy induction via the ERK1/2 MAPK-MTOR and p38 MAPK-MTOR pathway. Taken together, our data suggest that SVV-induced autophagy has finely tuned molecular mechanisms in which VP1, VP3, and 3C contribute synergistically to the AKT-AMPK-MAPK-MTOR pathway. IMPORTANCE Autophagy is an essential cellular catabolic process to sustain normal physiological processes that are modulated by a variety of signaling pathways. Invading virus is a stimulus to induce autophagy that regulates viral replication. It has been demonstrated that Seneca Valley virus (SVV) induced autophagy via the PERK and ATF6 unfolded protein response pathways. However, the precise signaling pathway involved in autophagy is still poorly understood. In this study, our results demonstrated that viral proteins VP1, VP3, and 3C contribute synergistically to activation of the AKT-AMPK-MAPK-MTOR signaling pathway for SVV-induced autophagy. These findings reveal systemically the finely tuned molecular mechanism of SVV-induced autophagy, thereby facilitating deeper insight into the development of potential control strategies against SVV infection.

A fluorescein-based fluorescent probe for fast detection of malondialdehyde and its imaging study.

A simple fluorescein derivative as a fluorescent probe was synthesized for the detection of malondialdehyde (MDA) through a synergistic reaction to achieve ring-opening of fluorescein and formation of a benzohydrazide derivative. It exhibited high sensitivity and selectivity for MDA detection. The probe could also detect MDA quickly (within 60 s) and visually via UV-vis and fluorescent modes. Moreover, this probe showed good performance in the imaging of MDA in living cells and bacteria.

Impact of influenza virus infection on lung microbiome in adults with severe pneumonia.

BACKGROUND: Bacterial and viral infections are commonly implicated in the development of pneumonia. We aimed to compare the diversity and composition of lung bacteria among severe pneumonia patients who were influenza virus positive (IFVP) and influenza virus negative (IFVN). METHODS: Bronchoalveolar lavage fluid specimens were procured from patients diagnosed with severe pneumonia to investigate the microbiome utilizing 16S-rDNA sequencing. The alpha diversity of the microbiome was evaluated employing Chao1, Shannon, and Simpson indexes, while the beta diversity was assessed using principal component analysis and principal coordinate analysis. Linear discriminant analysis effect size (LEfSe) was employed to determine the taxonomic differences between the IFVP and IFVN groups. RESULTS: A total of 84 patients with 42 in the IFVP group and 42 in the IFVN group were enrolled. Slightly higher indexes of Shannon and Simpson were observed in the IFVP group without statistically significant difference. The dominant bacterial genera were Streptococcus, Klebsiella, Escherichia-Shigella in the IFVN group and Acinetobacter, Streptococcus, Staphylococcus in the IFVP group. Streptococcus pneumoniae and Acinetobacter baumannii were the most abundant species in the IFVN and IFVP groups, respectively. LEfSe analysis indicated a greater abundance of Klebsiella in the IFVN group. CONCLUSIONS: Individuals with severe pneumonia infected with IFV exhibit heightened susceptibility to certain bacteria, especially Acinetobacter baumannii, and the underlying mechanism of the interaction between IFV and Acinetobacter baumannii in the progression of pneumonia needs further investigation.

Discriminatively Unsupervised Learning Person Re-Identification via Considering Complicated Images.

State-of-the-art purely unsupervised learning person re-ID methods first cluster all the images into multiple clusters and assign each clustered image a pseudo label based on the cluster result. Then, they construct a memory dictionary that stores all the clustered images, and subsequently train the feature extraction network based on this dictionary. All these methods directly discard the unclustered outliers in the clustering process and train the network only based on the clustered images. The unclustered outliers are complicated images containing different clothes and poses, with low resolution, severe occlusion, and so on, which are common in real-world applications. Therefore, models trained only on clustered images will be less robust and unable to handle complicated images. We construct a memory dictionary that considers complicated images consisting of both clustered and unclustered images, and design a corresponding contrastive loss by considering both kinds of images. The experimental results show that our memory dictionary that considers complicated images and contrastive loss can improve the person re-ID performance, which demonstrates the effectiveness of considering unclustered complicated images in unsupervised person re-ID.

Fowl Adenovirus Serotype 4 Induces Hepatic Steatosis via Activation of Liver X Receptor-α.

Fowl adenovirus serotype 4 (FAdV-4) is a hepatotropic virus that causes severe hepatic damage characterized by basophilic intranuclear inclusion bodies, vacuolar degeneration, and multifocal necrosis in hepatocytes. Many aspects of FAdV-4 infection and pathogenesis, however, remain unknown. Here, we found that FAdV-4-induced hepatic injury is accompanied by the accumulation of oil droplets (triglycerides) in the cytoplasm of hepatocytes, a typical indicator of steatosis, in FAdV-4-infected chickens. Significant upregulation of adipose synthesis-related genes, such as liver X receptor-α (LXR-α), peroxisome proliferator-activated receptor gamma (PPAR-γ), and sterol regulatory element-binding protein-1c (SREBP-1c), and significant downregulation of low-density lipoprotein secretion-related genes and lipid oxidation- and lipid decomposition-related genes were observed in the infected chickens. FAdV-4 infection in cultured leghorn male hepatoma (LMH) cells caused similar signs of steatosis, with alterations in various lipogenesis-related genes. We eliminated the effect of LXR-α activation on FAdV-4-induced steatosis and found that treatment with an LXR-α antagonist (SR9243) and RNA interference (small interfering RNA targeting LXR-α [Si-LXR-α]) decreased the number of oil droplets and the accumulation of lipogenic genes, but treatment with an LXR-α agonist (T0901317) increased the number of oil droplets and the accumulation of lipogenic genes in the cells. Additionally, SR9243 treatment or Si-LXR-α transfection led to significant reductions in viral DNA level, protein expression, and virus production, whereas T0901317 treatment caused significant increases in viral DNA level, protein expression, and virus production. However, inhibition of SREBP-1c activity had no significant effect on virus production. Collectively, these results indicated that FAdV-4-induced steatosis involves activation of the LXR-α signaling pathway, which might be a molecular mechanism underlying the hepatic injury associated with FAdV-4 infection.IMPORTANCE Fowl adenovirus serotype 4 (FAdV-4) is an important hepatotropic adenovirus in chicken, but the underlying mechanism of FAdV-4-induced hepatic injury remains unclear. We report here that infection with FAdV-4 induced the accumulation of oil droplets (triglycerides) in the cytoplasm of hepatocytes, a typical indicator of steatosis, in the livers of chickens. FAdV-4-induced steatosis might be caused by a disrupted balance of fat metabolism, as evidenced by differential regulation of various lipase genes. The significant upregulation of liver X receptor-α (LXR-α) prompted us to investigate the interplay between LXR-α activation and FAdV-4-induced steatosis. Treatment with an agonist, an antagonist, or RNA interference targeting LXR-α in cultured leghorn male hepatoma (LMH) cells indicated that FAdV-4-induced steatosis was dependent upon LXR-α activation, which contributed to virus replication. These results provide important mechanistic insights, revealing that FAdV-4 induces hepatic steatosis by activating the LXR-α signaling pathway and highlighting the therapeutic potential of strategies targeting the LXR-α pathway for the treatment of FAdV-4 infection.

A review and meta-analysis of the epidemiology and clinical presentation of coxsackievirus A6 causing hand-foot-mouth disease in China and global implications.

Coxsackievirus A6 (CV-A6) has been associated with increasingly occurred sporadic hand-foot-mouth disease (HFMD) cases and outbreak events in many countries. In order to understand epidemiological characteristics of CV-A6, we collected the information describing HFMD caused by CV-A6 to describe the detection rate, severe rate and onychomadesis rate, which is defined as one or more nails defluvium, caused by CV-A6 from 2007 to 2017. The results showed that there was an outbreak of CV-A6 every other year, and overall trend of the epidemic of CA6-associated HFMD was increasing in China. The detection rate of CV-A6 in other countries was 32.0% (95% CI: 25.0%~40.0%) before 2013 and 28.0% (95% CI: 20.0%~36.0%) after 2013, respectively. Although the severe rate of HFMD caused by CV-A6 was low (0.10%, 95% CI: 0.01%~0.20%), CV-A6 can cause a high incidence of onychomadesis (28.0%, 95%CI: 21.9%-34.3%). Thus, it would be worthwhile to research and develop an effective multivalent vaccine for CV-A6 to achieve a more powerful prevention of HMFD.

Induction of Porcine Dermatitis and Nephropathy Syndrome in Piglets by Infection with Porcine Circovirus Type 3.

Porcine circovirus type 3 (PCV3) is an emerging porcine circovirus that has been associated with porcine dermatitis and nephropathy syndrome (PDNS)-like clinical signs, reproductive failure, cardiac pathologies, and multisystemic inflammation in piglets and sows. Many aspects of PCV3 infection biology and pathogenesis, however, remain unknown. Here, we used a PCV3 virus stock from the rescue of an infectious PCV3 DNA clone to intranasally inoculate 4- and 8-week-old specific-pathogen-free piglets for evaluation of PCV3 pathogenesis. For 4-week-old piglets, typical clinical signs resembling those of PDNS-like disease were observed when piglets were inoculated with PCV3 alone or PCV3 combined with immunostimulation by keyhole limpet hemocyanin, with a mortality of 40% (2/5) for both types of inoculated piglets during a 28-day observation period postinoculation. Both types of inoculated piglets showed similar progressive increases in viral loads in the sera and had seroconverted to PCV3 capsid antibody after inoculation. Pathological lesions and PCV3-specific antigen were detected in various tissues and organs, including the lung, heart, kidney, lymph nodes, spleen, liver, and small intestine, in both types of inoculated piglets. The levels of proinflammatory cytokines and chemokines, including interleukin 1 beta (IL-1ß), IL-6, IL-23α, gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and chemokine ligand 5 (CCL5), were significantly upregulated in both groups of inoculated piglets. Eight-week-old piglets also exhibited a similar PDNS-like disease but without death after PCV3 inoculation, as evidenced by pathological lesions and PCV3 antigen in various tissues and organs. These results show for the first time successful reproduction of PDNS-like disease by PCV3 infection and further provide significant information regarding the pathogenesis of PCV3 in piglets.IMPORTANCE Porcine circovirus type 3 (PCV3), an emerging porcine circovirus, is considered the cause of porcine dermatitis and nephropathy syndrome (PDNS)-like clinical signs and other systemic diseases in piglets and sows. To evaluate the pathogenesis of PCV3 infection in vivo, we used a PCV3 virus stock from the rescue of an infectious PCV3 DNA clone to intranasally inoculate 4- and 8-week-old specific-pathogen-free piglets and demonstrated successful reproduction of PDNS-like disease in animals that were inoculated with PCV3 alone or PCV3 combined with immunostimulation by keyhole limpet hemocyanin. Both 4- and 8-week-old PCV3-inoculated piglets showed similar increases in viral loads in the sera and had seroconverted to PCV3 capsid antibody. Pathological lesions and PCV3-specific antigen were detected in various tissues and organs, while numerous proinflammatory cytokines and chemokines in the sera were significantly upregulated after PCV3 inoculation. These results will provide significant information regarding the pathogenesis of PCV3 in piglets.

[Histone H3K27me3 in the regulation of skeletal muscle development].

Histone methylation is a modification which occurs in the N-terminal peptide chains of the histone nucleosome. The 4th, 9th, 27th, 36th and 79th lysines in N-terminal peptide chain of histone H3 are hot spots for this modification, including mono-, di-, and tri-methylation. H3K27me3 is the tri-methylation modification on histone H3 lysine 27, which mainly functions as a transcriptional repressor regulating skeletal muscle development. Studies have shown that H3K27me3 can finely regulate skeletal muscle proliferation, including the level and duration of skeletal muscle development by specifically binding to myogenic regulatory factors (e.g., MyoD, MyoG, etc.), cell cycling regulators, and epigenetic regulators including lncRNA and miRNA. In this review, we introduce the types and mechanisms of histone methylation and de-methylation of H3K27. We also summarize how H3K27me3 functions in the proliferation and differentiation of skeletal muscle cell. This review will contribute to the comprehension of the function of H3K27me3 in regulating skeletal muscle development and provide reference for further improving our understanding of mammalian muscle.

[Effects of RNA interference on the porcine NHEJ pathway repair factors on HR efficiency].

Non-homologous end-joining (NHEJ) is the predominant DNA double-strand break (DSB) repair pathway in mammalian cells. It inhibits the efficiency of homologous recombination (HR) by competing for DSB targets. To improve the efficiency of HR in porcine fetal fibroblasts (PFFs), several RNA interference (RNAi) systems were designed to knockdown NHEJ key molecules, such as polynucleotide kinase/phosphatase (PNKP), DNA ligase IV (LIG4) and NHEJ1. The results show that siRNA significantly knocked down LIG4, PNKP and NHEJ1 expression. Suppression of PNKP dramatically increased the efficiency of single-strand annealing (SSA), double-strand DNA (dsDNA) and single-strand DNA (ssODN) mediated homology-directed repair (HDR) by 55.7%, 37.4% and 73.1% after transfected with the SSA-GFP reporter, HDR-GFP system or ssODN-GFP system, respectively; whereas knockdown of LIG4 and NHEJ1 repair factors significantly increased dsDNA or ssODN-mediated HDR efficiency by 37.5% and 76.9%, respectively.

Transcriptional profiles in bursal B-lymphoid DT40 cells infected with very virulent infectious bursal disease virus.

BACKGROUND: Infectious bursal disease virus (IBDV) causes a highly contagious, immunosuppressive disease in chickens. The virus mainly infects immature B lymphocytes in the bursa of Fabricius (BF). Chicken B cell line DT40, an avian leukosis virus-induced B cell line, supports very virulent IBDV (vvIBDV) infection in vitro and thereby serves as a good model for investigating the infection and pathogenesis of this virus. However, a transcriptome-wide understanding of the interaction between vvIBDV and B cells has not yet been achieved. This study aimed to employ time-course DNA microarrays to investigate gene expression patterns in DT40 cells after infection with vvIBDV strain LX. RESULTS: DT40 cells infected with vvIBDV exhibited alterations in the expression of many important host genes involved in signal transduction pathways, including MAPK signaling, PI3K/mTOR signaling, cell death and survival, BCR signaling, and antigen presentation. The changes in cellular mRNA levels identified by microarray analysis were confirmed for 8 selected genes using real-time reverse transcription-PCR. The upregulation of inflammatory cytokines and Toll-like receptors (TLRs) in the bursa of vvIBDV-infected chickens might involve excessive activation of the innate immune and inflammatory responses and contribute to tissue damage. CONCLUSIONS: The present study is the first to provide a comprehensive differential transcriptional profile of cultured DT40 cells in response to vvIBDV infection and further extends our understanding of the molecular mechanisms underlying vvIBDV infection and pathogenesis.

Advances in site-specific integration of transgene in animal genome.

The traditional transgenic technologies, such as embryo microinjection, transposon-mediated integration, or lentiviral transfection, usually result in random insertions of the foreign DNA into the host genome, which could have various disadvantages in the establishment of transgenic animals. Therefore, a strategy for site-specific integration of a transgene is needed to generate genetically modified animals with accurate and identical genotypes. However, the efficiency for site-specific integration of transgene is very low, which is mainly caused by two issues. The first one is the low efficiency of inducing double-strand break (DSB) at the target site of host genome in the initial process. The second one is the low efficiency of homologous recombination repair (HDR) between the target site and the donor plasmid carrying homologous arm and foreign genes. HDR is the most common mechanism for site-specific integration of a transgene. DSBs can stimulate DNA repair mainly by two competitive mechanisms, HDR and nonhomologous end joining (NHEJ). Hence, activation of HDR or inhibition of NHEJ can promote the HDR in the integration processes, thereby optimizing a specific targeting of the transgene. In this review, we summarize the recent advances in strategies for improving the site-specific integration of foreign transgene in transgenic technologies.

Effects of parameters, plasmid dosages and topological structures on transfection efficiency of porcine fetal fibroblasts using different electroporators.

To obtain an ideal transfection efficiency of porcine fetal fibroblasts, fluorescence activated cell sorting (FACS) was used to optimize parameters for transfection of porcine fetal fibroblasts (PFFs) with ECM? 830, NEPA 21 and Nucleofector? 2b in different conditions such as electroporation parameters, plasmid dosages and topological structures. The results show that the optimum poring pulse parameter of NEPA 21 is voltage 200 V, continuous 3 ms, interval 50 ms, 3 times, voltage attenuation range of 10%; and the transfection efficiency of Nucleofector? 2b is highest under U-023 program. Under the optimum conditions, FACS analysis demonstrates that Nucleofector? 2b and ECM? 830 have the highest transfection efficiency when transfecting 10 µg supercoiled plasmids into PFFs, and 8 µg for NEPA 21. Supercoiled plasmids show higher transfection efficiencies than linearized plasmids. Moreover, Nucleofector? 2b has the highest transfection efficiency among the three electroporation instruments. This study paves the way to generate transgenic or gene editing pigs with high efficiency.

Safety evaluation of multiple strains of Lactobacillus plantarum and Pediococcus pentosaceus in Wistar rats based on the Ames test and a 28-day feeding study.

Three lactic acid bacterial strains, Lactobacillus plantarum, HK006, and HK109, and Pediococcus pentosaceus PP31 exhibit probiotic potential as antiallergy agents, both in vitro and in vivo. However, the safety of these new strains requires evaluation when isolated from infant faeces or pickled cabbage. Multiple strains (HK006, HK109, and PP31) were subject to a bacterial reverse mutation assay and a short-term oral toxicity study. The powder product exhibited mutagenic potential in Salmonella Typhimurium strains TA98 and TA1535 (with or without metabolic activation). In the short-term oral toxicity study, rats received a normal dosage of 390 mg/kg/d (approximately 9 × 10(9) CFU/kg/d) or a high dosage of 1950 mg/kg/d (approximately 4.5 × 10(10) CFU/kg/d) for 28 d. No adverse effects were observed regarding the general condition, behaviour, growth, feed and water consumption, haematology, clinical chemistry indices, organ weights, or histopathologic analysis of the rats. These studies have demonstrated that the consumption of multiple bacterial strains is not associated with any signs of mutagenicity of S. Typhimurium or toxicity in Wistar rats, even after consuming large quantities of bacteria.

Quantitative proteomic analysis of PK-15 cells infected with porcine circovirus type 3 using 4D-DIA approach.

Porcine circovirus type 3 (PCV3) infection is clinically related to various diseases, including porcine dermatitis and nephrotic syndrome (PDNS)-like disease, respiratory disease, reproductive disorders, and gastrointestinal and neurological diseases. Since PCV3 infection was discovered in 2016, it has developed rapidly and has attracted much attention worldwide. However, specific preventive and therapeutic interventions are currently lacking. In this study, four-dimensional (4D) data-independent acquisition (DIA)-based quantitative proteomics detection combined with bioinformatics analysis were employed to quantitatively identify the differentially expressed proteins in PK-15 cells from the PCV3-infected group compared with those from the uninfected control group. A total of 194 cellular proteins were significantly altered in response to PCV3 infection, including 58 upregulated proteins and 136 downregulated proteins. In our Gene Ontology (GO) enrichment analysis, these differentially expressed proteins were mostly associated with cellular anatomical entities, binding, cellular processes, biological regulation, catalytic activity, metabolic processes, developmental processes, protein-containing complexes and responses to stimuli. Our Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the DEPs were predominantly involved in metabolic pathways, the cAMP signaling pathway, protein processing in the endoplasmic reticulum, the PI3K-Akt signaling pathway, and the calcium signaling pathway. For the experiments, Western blotting (WB) was used to confirm the changes in important molecules. The differentially expressed proteins identified should contribute to a greater understanding of the mechanism of PCV3 replication and pathogenesis, as well as the host response.

Seneca Valley virus 3C protease cleaves OPTN (optineurin) to Impair selective autophagy and type I interferon signaling.

Seneca Valley virus (SVV) causes vesicular disease in pigs, posing a threat to global pork production. OPTN (optineurin) is a macroautophagy/autophagy receptor that restricts microbial propagation by targeting specific viral or bacterial proteins for degradation. OPTN is degraded and cleaved at glutamine 513 following SVV infection via the activity of viral 3C protease (3C[pro]), resulting in N-terminal and a C-terminal OPTN fragments. Moreover, OPTN interacts with VP1 and targets VP1 for degradation to inhibit viral replication. The N-terminal cleaved OPTN sustained its interaction with VP1, whereas the degradation capacity targeting VP1 decreased. The inhibitory effect of N-terminal OPTN against SVV infection was significantly reduced, C-terminal OPTN failed to inhibit viral replication, and degradation of VP1 was blocked. The knockdown of OPTN resulted in reduced TBK1 activation and phosphorylation of IRF3, whereas overexpression of OPTN led to increased TBK1-IRF3 signaling. Additionally, the N-terminal OPTN diminished the activation of the type I IFN (interferon) pathway. These results show that SVV 3C[pro] targets OPTN because its cleavage impairs its function in selective autophagy and type I IFN production, revealing a novel model in which the virus develops diverse strategies for evading host autophagic machinery and type I IFN response for survival.Abbreviations: Co-IP: co-immunoprecipitation; GFP-green fluorescent protein; hpi: hours post-infection; HRP: horseradish peroxidase; IFN: interferon; IFNB/IFN-ß: interferon beta; IRF3: interferon regulatory factor 3; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MOI: multiplicity of infection; OPTN: optineurin; PBS: phosphate-buffered saline; SVV: Seneca Valley virus; SQSTM1: sequestosome 1; TAX1BP1: Tax1 binding protein 1; TBK1: TANK binding kinase 1; TCID50: 50% tissue culture infectious doses; UBAN: ubiquitin binding in TNIP/ABIN (TNFAIP3/A20 and inhibitor of NFKB/NF-kB) and IKBKG/NEMO; UBD: ubiquitin-binding domain; ZnF: zinc finger.

Avian metapneumovirus subgroup C infection in chickens, China.

Avian metapneumovirus causes acute respiratory tract infection and reductions in egg production in various avian species. We isolated and characterized an increasingly prevalent avian metapneumovirus subgroup C strain from meat-type commercial chickens with severe respiratory signs in China. Culling of infected flocks could lead to economic consequences.

miR-9 modulates the expression of interferon-regulated genes and MHC class I molecules in human nasopharyngeal carcinoma cells.

The functions of miR-9 in some cancers are recently implicated in regulating proliferation, epithelial-mesenchymal transition (EMT), invasion and metastasis, apoptosis, and tumor angiogenesis, etc. miR-9 is commonly down-regulated in nasopharyngeal carcinoma (NPC), but the exact roles of miR-9 dysregulation in the pathogenesis of NPC remains unclear. Therefore, we firstly used miR-9-expressing CNE2 cells to determine the effects of miR-9 overexpression on global gene expression profile by microarray analysis. Microarray-based gene expression data unexpectedly demonstrated a significant number of up- or down-regulated immune- and inflammation-related genes, including many well-known interferon (IFN)-induced genes (e.g., IFI44L, PSMB8, IRF5, PSMB10, IFI27, PSB9_HUMAN, IFIT2, TRAIL, IFIT1, PSB8_HUMAN, IRF1, B2M and GBP1), major histocompatibility complex (MHC) class I molecules (e.g., HLA-B, HLA-C, HLA-F and HLA-H) and interleukin (IL)-related genes (e.g., IL20RB, GALT, IL7, IL1B, IL11, IL1F8, IL1A, IL6 and IL7R), which was confirmed by qRT-PCR. Moreover, the overexpression of miR-9 with the miRNA mimics significantly up- or down-regulated the expression of above-mentioned IFN-inducible genes, MHC class I molecules and IL-related genes; on the contrary, miR-9 inhibition by anti-miR-9 inhibitor in CNE2 and 5-8F cells correspondingly decreased or increased the aforementioned immune- and inflammation-related genes. Taken together, these findings demonstrate, for the first time, that miR-9 can modulate the expression of IFN-induced genes and MHC class I molecules in human cancer cells, suggesting a novel role of miR-9 in linking inflammation and cancer, which remains to be fully characterized.

Porcine reproductive and respiratory syndrome virus induces interleukin-15 through the NF-κB signaling pathway.

Porcine reproductive and respiratory syndrome virus (PRRSV) mainly infects macrophages/dendritic cells and modulates cytokine expression in these cells. Interleukin-15 (IL-15) is a pleiotropic cytokine involved in wide range of biological activities. It has been shown to be essential for the generation, activation, and proliferation of NK and NKT cells and for the survival and activation of CD8(+) effector and memory T cells. In this study, we discovered that PRRSV infection upregulated IL-15 production at both the mRNA and protein levels in porcine alveolar macrophages (PAMs), blood monocyte-derived macrophages (BMo), and monocyte-derived dendritic cells (DCs). We subsequently demonstrated that the NF-κB signaling pathway was essential for PRRSV infection-induced IL-15 production. First, addition of an NF-κB inhibitor drastically reduced PRRSV infection-induced IL-15 production. We then found that NF-κB was indeed activated upon PRRSV infection, as evidenced by IκB phosphorylation and degradation. Moreover, we revealed an NF-κB binding motif in the cloned porcine IL-15 (pIL-15) promoter, deletion of which abrogated the pIL-15 promoter activity in PRRSV-infected alveolar macrophages. In addition, we demonstrated that PRRSV nucleocapsid (N) protein had the ability to induce IL-15 production in porcine alveolar macrophage cell line CRL2843 by transient transfection, which was mediated by its multiple motifs, and it also activated NF-κB. These data indicated that PRRSV infection-induced IL-15 production was likely through PRRSV N protein-mediated NF-κB activation. Our findings provide new insights into the molecular mechanisms underling the IL-15 production induced by PRRSV infection.