Glutathione-Stabilized Fluorescent Gold Nanoclusters Vary in Their Influences on the Proliferation of Pseudorabies Virus and Porcine Reproductive and Respiratory Syndrome Virus

Gold nanoclusters (Au NCs) are widely used in biological imaging and antitumor treatment because of their excellent cell membrane permeability, good fluorescence properties, and high biocompatibility. However, their effects on viruses are still largely unknown. Here, pseudorabies virus (PRV) and porcine reproductive and respiratory syndrome virus (PRRSV) were used respectively as the models of DNA virus and RNA virus to investigate the influences of glutathione-stabilized fluorescent Au NCs on viruses by plaque assay, indirect immunofluorescence assay, quantitative real-time polymerase chain reaction assay, and Western blot assay. The experimental data indicated that Au NCs selectively inhibited proliferation and protein expression of PRRSV but not that of PRV. Mechanistically, Au NCs directly inactivated PRRSV and blocked viral adsorption but showed no effect on viral genome replication. These findings prompt the possibility of developing Au NCs as an effective specific antiviral nanomaterial against RNA virus infection in the future

Glutathione-Capped Ag₂S Nanoclusters Inhibit Coronavirus Proliferation through Blockage of Viral RNA Synthesis and Budding

Development of novel antiviral reagents is of great importance for the control of virus spread. Here, Ag₂S nanoclusters (NCs) were proved for the first time to possess highly efficient antiviral activity by using porcine epidemic diarrhea virus (PEDV) as a model of coronavirus. Analyses of virus titers showed that Ag₂S NCs significantly suppressed the infection of PEDV by about 3 orders of magnitude at the noncytotoxic concentration at 12 h postinfection, which was further confirmed by the expression of viral proteins. Mechanism investigations indicated that Ag₂S NCs treatment inhibits the synthesis of viral negative-strand RNA and viral budding. Ag₂S NCs treatment was also found to positively regulate the generation of IFN-stimulating genes (ISGs) and the expression of proinflammation cytokines, which might prevent PEDV infection. This study suggest the novel underlying of Ag₂S NCs as a promising therapeutic drug for coronavirus

Quantitative Proteomic Analysis Reveals That Transmissible Gastroenteritis Virus Activates the JAK-STAT1 Signaling Pathway

Transmissible gastroenteritis virus (TGEV), a porcine enteropathogenic coronavirus, causes lethal watery diarrhea and severe dehydration in piglets. In this study, liquid chromatography–tandem mass spectrometry coupled to isobaric tags for relative and absolute quantification labeling was used to quantitatively identify differentially expressed cellular proteins after TGEV infection in PK-15 cells. In total, 162 differentially expressed cellular proteins were identified, including 60 upregulated proteins and 102 downregulated proteins. These differentially expressed proteins were involved in the cell cycle, cellular growth and proliferation, the innate immune response, etc. Interestingly, many upregulated proteins were associated with interferon signaling, especially signal transducer and activator of transcription 1 (STAT1) and interferon-stimulated genes (ISGs). Immunoblotting and real-time quantitative reverse transcription polymerase chain reaction demonstrated that TGEV infection induces STAT1 phosphorylation and nuclear translocation, as well as ISG expression. This study for the first time reveals that TGEV induces interferon signaling from the point of proteomic analysis

Label-Free Quantitative Phosphoproteomic Analysis Reveals Differentially Regulated Proteins and Pathway in PRRSV-Infected Pulmonary Alveolar Macrophages

Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen of swine worldwide and causes significant economic losses. Through regulating the host proteins phosphorylation, PRRSV was found to manipulate the activities of several signaling molecules to regulate innate immune responses. However, the role of protein phosphorylation during PRRSV infection and the signal pathways responsible for it are relatively unknown. Here liquid chromatography–tandem mass spectrometry for label-free quantitative phosphoproteomics was applied to systematically investigate the global phosphorylation events in PRRSV-infected pulmonary alveolar macrophages. In total, we identified 2125 unique phosphosites, of which the phosphorylation level of 292 phosphosites on 242 proteins and 373 phosphosites on 249 proteins was significantly altered at 12 and 36 h pi, respectively. The phosphoproteomics data were analyzed using ingenuity pathways analysis to identify defined canonical pathways and functional networks. Pathway analysis revealed that PRRSV-induced inflammatory cytokines production was probably due to the activation of mitogen-activated protein kinase and NF-κB signal pathway, which were regulated by several protein kinases during virus infection. Interacting network analysis indicated that altered phosphoproteins were involved in cellular assembly and organization, protein synthesis, molecular transport, and signal transduction in PRRSV infected cells. These pathways and functional networks analysis could provide direct insights into the biological significance of phosphorylation events modulated by PRRSV and may help us elucidate the pathogenic mechanisms of PRRSV infection

Quantitative Proteomic Analysis Reveals That Transmissible Gastroenteritis Virus Activates the JAK-STAT1 Signaling Pathway

Transmissible gastroenteritis virus (TGEV), a porcine enteropathogenic coronavirus, causes lethal watery diarrhea and severe dehydration in piglets. In this study, liquid chromatography–tandem mass spectrometry coupled to isobaric tags for relative and absolute quantification labeling was used to quantitatively identify differentially expressed cellular proteins after TGEV infection in PK-15 cells. In total, 162 differentially expressed cellular proteins were identified, including 60 upregulated proteins and 102 downregulated proteins. These differentially expressed proteins were involved in the cell cycle, cellular growth and proliferation, the innate immune response, etc. Interestingly, many upregulated proteins were associated with interferon signaling, especially signal transducer and activator of transcription 1 (STAT1) and interferon-stimulated genes (ISGs). Immunoblotting and real-time quantitative reverse transcription polymerase chain reaction demonstrated that TGEV infection induces STAT1 phosphorylation and nuclear translocation, as well as ISG expression. This study for the first time reveals that TGEV induces interferon signaling from the point of proteomic analysis

Label-Free Quantitative Phosphoproteomic Analysis Reveals Differentially Regulated Proteins and Pathway in PRRSV-Infected Pulmonary Alveolar Macrophages

Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen of swine worldwide and causes significant economic losses. Through regulating the host proteins phosphorylation, PRRSV was found to manipulate the activities of several signaling molecules to regulate innate immune responses. However, the role of protein phosphorylation during PRRSV infection and the signal pathways responsible for it are relatively unknown. Here liquid chromatography–tandem mass spectrometry for label-free quantitative phosphoproteomics was applied to systematically investigate the global phosphorylation events in PRRSV-infected pulmonary alveolar macrophages. In total, we identified 2125 unique phosphosites, of which the phosphorylation level of 292 phosphosites on 242 proteins and 373 phosphosites on 249 proteins was significantly altered at 12 and 36 h pi, respectively. The phosphoproteomics data were analyzed using ingenuity pathways analysis to identify defined canonical pathways and functional networks. Pathway analysis revealed that PRRSV-induced inflammatory cytokines production was probably due to the activation of mitogen-activated protein kinase and NF-κB signal pathway, which were regulated by several protein kinases during virus infection. Interacting network analysis indicated that altered phosphoproteins were involved in cellular assembly and organization, protein synthesis, molecular transport, and signal transduction in PRRSV infected cells. These pathways and functional networks analysis could provide direct insights into the biological significance of phosphorylation events modulated by PRRSV and may help us elucidate the pathogenic mechanisms of PRRSV infection

Quantitative Proteomic Analysis Reveals That Transmissible Gastroenteritis Virus Activates the JAK-STAT1 Signaling Pathway

Transmissible gastroenteritis virus (TGEV), a porcine enteropathogenic coronavirus, causes lethal watery diarrhea and severe dehydration in piglets. In this study, liquid chromatography–tandem mass spectrometry coupled to isobaric tags for relative and absolute quantification labeling was used to quantitatively identify differentially expressed cellular proteins after TGEV infection in PK-15 cells. In total, 162 differentially expressed cellular proteins were identified, including 60 upregulated proteins and 102 downregulated proteins. These differentially expressed proteins were involved in the cell cycle, cellular growth and proliferation, the innate immune response, etc. Interestingly, many upregulated proteins were associated with interferon signaling, especially signal transducer and activator of transcription 1 (STAT1) and interferon-stimulated genes (ISGs). Immunoblotting and real-time quantitative reverse transcription polymerase chain reaction demonstrated that TGEV infection induces STAT1 phosphorylation and nuclear translocation, as well as ISG expression. This study for the first time reveals that TGEV induces interferon signaling from the point of proteomic analysis

Label-Free Quantitative Phosphoproteomic Analysis Reveals Differentially Regulated Proteins and Pathway in PRRSV-Infected Pulmonary Alveolar Macrophages

Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen of swine worldwide and causes significant economic losses. Through regulating the host proteins phosphorylation, PRRSV was found to manipulate the activities of several signaling molecules to regulate innate immune responses. However, the role of protein phosphorylation during PRRSV infection and the signal pathways responsible for it are relatively unknown. Here liquid chromatography–tandem mass spectrometry for label-free quantitative phosphoproteomics was applied to systematically investigate the global phosphorylation events in PRRSV-infected pulmonary alveolar macrophages. In total, we identified 2125 unique phosphosites, of which the phosphorylation level of 292 phosphosites on 242 proteins and 373 phosphosites on 249 proteins was significantly altered at 12 and 36 h pi, respectively. The phosphoproteomics data were analyzed using ingenuity pathways analysis to identify defined canonical pathways and functional networks. Pathway analysis revealed that PRRSV-induced inflammatory cytokines production was probably due to the activation of mitogen-activated protein kinase and NF-κB signal pathway, which were regulated by several protein kinases during virus infection. Interacting network analysis indicated that altered phosphoproteins were involved in cellular assembly and organization, protein synthesis, molecular transport, and signal transduction in PRRSV infected cells. These pathways and functional networks analysis could provide direct insights into the biological significance of phosphorylation events modulated by PRRSV and may help us elucidate the pathogenic mechanisms of PRRSV infection

Glutathione-Capped Ag₂S Nanoclusters Inhibit Coronavirus Proliferation through Blockage of Viral RNA Synthesis and Budding

Development of novel antiviral reagents is of great importance for the control of virus spread. Here, Ag₂S nanoclusters (NCs) were proved for the first time to possess highly efficient antiviral activity by using porcine epidemic diarrhea virus (PEDV) as a model of coronavirus. Analyses of virus titers showed that Ag₂S NCs significantly suppressed the infection of PEDV by about 3 orders of magnitude at the noncytotoxic concentration at 12 h postinfection, which was further confirmed by the expression of viral proteins. Mechanism investigations indicated that Ag₂S NCs treatment inhibits the synthesis of viral negative-strand RNA and viral budding. Ag₂S NCs treatment was also found to positively regulate the generation of IFN-stimulating genes (ISGs) and the expression of proinflammation cytokines, which might prevent PEDV infection. This study suggest the novel underlying of Ag₂S NCs as a promising therapeutic drug for coronavirus

Label-Free Quantitative Phosphoproteomic Analysis Reveals Differentially Regulated Proteins and Pathway in PRRSV-Infected Pulmonary Alveolar Macrophages

Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen of swine worldwide and causes significant economic losses. Through regulating the host proteins phosphorylation, PRRSV was found to manipulate the activities of several signaling molecules to regulate innate immune responses. However, the role of protein phosphorylation during PRRSV infection and the signal pathways responsible for it are relatively unknown. Here liquid chromatography–tandem mass spectrometry for label-free quantitative phosphoproteomics was applied to systematically investigate the global phosphorylation events in PRRSV-infected pulmonary alveolar macrophages. In total, we identified 2125 unique phosphosites, of which the phosphorylation level of 292 phosphosites on 242 proteins and 373 phosphosites on 249 proteins was significantly altered at 12 and 36 h pi, respectively. The phosphoproteomics data were analyzed using ingenuity pathways analysis to identify defined canonical pathways and functional networks. Pathway analysis revealed that PRRSV-induced inflammatory cytokines production was probably due to the activation of mitogen-activated protein kinase and NF-κB signal pathway, which were regulated by several protein kinases during virus infection. Interacting network analysis indicated that altered phosphoproteins were involved in cellular assembly and organization, protein synthesis, molecular transport, and signal transduction in PRRSV infected cells. These pathways and functional networks analysis could provide direct insights into the biological significance of phosphorylation events modulated by PRRSV and may help us elucidate the pathogenic mechanisms of PRRSV infection