To screen and identify the key host proteins interacting with the non-structural protein 15 (Nsp15) of porcine epidemic diarrhea virus (PEDV). The IP/pull-down assay and mass spectrometry were employed to screen and identify the host proteins interacting with Nsp15. The interaction between the host protein and Nsp15 was studied by co-immunoprecipitation and laser scanning confocal microscopy. Finally, Western blotting and RT-qPCR were employed to examine the interaction between SLC25a3 and PEDV. The recombinant eukaryotic expression vector pcDNA3.1(+)-Flag-Nsp15 was successfully constructed, and the host protein SLC25a3 interacting with PEDV Nsp15 was screened out. An interaction existed between SLC25a3 and Nsp15, and SLC25a3 significantly inhibited PEDV replication in a dose-dependent manner. SLC25a3 inhibits PEDV replication. The results of this study provide a basis for deciphering the role and mechanism of SLC25a3 in the host immune response to PEDV infection.
Porcine epidemic diarrhea virus/genetics* ; Viral Nonstructural Proteins/metabolism* ; Animals ; Swine ; Virus Replication ; Coronavirus Infections/veterinary* ; Swine Diseases/metabolism*

Porcine deltacoronavirus (PDCoV) is a major pathogen causing fatal diarrhea in suckling piglets, and there is currently a lack of effective vaccines and drugs to prevent and control the virus. The nonstructural protein 13 (NSP13) serves as a virus-coded helicase and is considered to be a crucial target for antiviral drugs, making it imperative to investigate the helicase activity of NSP13. In this study, the NSP13 gene of PDCoV was synthesized and integrated into the prokaryotic expression vector pET-28a to construct the recombinant plasmid pET-28a-NSP13. NSP13 was successfully expressed in BL21 (DE3) and subsequently purified. The study also verified the helicase activity of the purified NSP13 and explored the factors that influence this activity. The results indicated that NSP13 from PDCoV was effectively expressed in the prokaryotic system and exhibited helicase activity, capable of unwinding double-stranded DNA with a tail at the 5' end. Additionally, NSP13 demonstrated an annealing function by promoting the complementary pairing of single-stranded nucleotide chains to form double strands. The helicase activity of NSP13 was affected by metal ions, but Mg²⁺concentrations in the range of 0.5-6.0 mmol/L had no significant effect on helicase activity of NSP13. When the solution pH was in the range of 4-9, there was no difference in helicase activity. ATP concentrations in the range of 0.25-6.00 mmol/L had a weak effect on helicase activity, and NSP13 concentration ≥80 nmol/L inhibited the helicase activity. We obtained the NSP13 of PDCoV and investigated its helicase activity. These findings provided a theoretical foundation for the further research on the regulatory mechanism of NSP13 in PDCoV replication and the development of anti-coronaviral drugs.
Viral Nonstructural Proteins/metabolism* ; Escherichia coli/metabolism* ; Recombinant Proteins/metabolism* ; Swine ; Animals ; DNA Helicases/metabolism* ; Genetic Vectors/metabolism*

Dengue virus (DENV) is the most widely transmitted arbovirus in the world. Due to the lack of diagnostic technology to quickly identify the virus serotypes in patients, severe dengue hemorrhagic fever cases caused by repeated infections remain high. To realize the rapid differential diagnosis of different serotypes of DENV infection by immunological methods, in this study, four DENV serotype NS1 proteins were expressed and purified in mammalian cells. Monoclonal antibodies (MAbs) against NS1 protein were obtained by hybridoma technology after immunizing BALB/c mice. Enzyme-linked immunosorbent assay, indirect immunofluorescence assay, dot blotting, and Western blotting were used to confirm the reactivity of MAbs to viral native NS1 and recombinant NS1 protein. These MAbs include not only the universal antibodies that recognize all DENV 1-4 serotype NS1, but also serotype-specific antibodies against DENV-1, DENV-2 and DENV-4. Double antibody sandwich ELISA was established based on these antibodies, which can be used to achieve rapid differential diagnosis of serotypes of DENV infection. Preparation of DENV serotype-specific MAbs and establishment of an ELISA technology for identifying DENV serotypes has laid the foundation for the rapid diagnosis of DENV clinical infection.
Animals ; Antibodies, Monoclonal ; Antibodies, Viral/metabolism* ; Dengue/diagnosis* ; Dengue Virus/immunology* ; Enzyme-Linked Immunosorbent Assay ; Humans ; Mice ; Mice, Inbred BALB C ; Sensitivity and Specificity ; Serogroup ; Viral Nonstructural Proteins/immunology*

The nonstructural protein 1 (NS1) of influenza A virus, which is absent from the viral particle, but highly expressed in infected cells, strongly antagonizes the interferon (IFN)-mediated antiviral response. We engineered an NS1-expressing 293 (293-NS1) cell line with no response to IFN stimulation. Compared with the parental 293 cells, the IFN-nonresponsive 293-NS1 cells improved the growth capacity of various viruses, but the introduction of NS1 barely enhanced the propagation of Tahyna virus, a negative-strand RNA virus. In particular, fastidious enteric adenovirus that replicates poorly in 293 cells may grow more efficiently in 293-NS1 cells; thus, IFN-nonresponsive 293-NS1 cells might be of great value in diagnostic laboratories for the cultivation and isolation of human enteric adenoviruses.
Cell Line ; Gene Expression Regulation ; HEK293 Cells ; Humans ; Influenza A virus ; physiology ; Viral Nonstructural Proteins ; genetics ; metabolism ; Virus Cultivation ; methods ; Virus Replication ; physiology

The present study was aimed to isolate the active compounds from the fermentation products of Fusarium oxysporum, which had hepatitis C virus (HCV) NS3 protease inhibitory activity. A bioactive compound was isolated by reverse-phase silica-gel column chromatography, silica-gel column chromatography, semi-preparative reverse-phase High Performance Liquid Chromatography (HPLC), and then its molecular structure was elucidated based on the spectrosopic analysis. As a result, the compound (H1-A, 1) Ergosta-5, 8 (14), 22-trien-7-one, 3-hydroxy-,(3β, 22E) was isolated and identified. To the best of our knowledge, this was the first report on the isolation of H1-A from microorganisms with the inhibitory activity of NS3 protease.
Enzyme Inhibitors ; chemistry ; isolation & purification ; metabolism ; Fusarium ; chemistry ; metabolism ; Hepacivirus ; drug effects ; enzymology ; genetics ; Hepatitis C ; virology ; Humans ; Magnetic Resonance Spectroscopy ; Viral Nonstructural Proteins ; antagonists & inhibitors ; metabolism

Until now, more than seventeen parvovirus have been reported which can infect mammals and poultries. The infected cells appeared different properties of apoptosis and death, present a typical cytopathic effect. NS1 is a major nonstructural protein of parvovirus, with a conservative structure and function, which plays an important role in the viral life cycle. In addition to the influence on viral replication, the NS1 also participates in apoptosis induced by viruses. Parvovirus induced apoptosis which is mainly mediated by mitochondrial pathway, this review summarized the latest research progresses of parvovirus induced apoptosis.
Animals ; Apoptosis ; Humans ; Parvoviridae Infections ; physiopathology ; veterinary ; virology ; Parvovirus ; genetics ; metabolism ; Viral Nonstructural Proteins ; genetics ; metabolism

Peg-interferon and ribavirin has been the standard therapy of chronic hepatitis C for the past 15 years in Korea. However, the treatment paradigm is changing. Direct acting agents (DAAs) are oral pills that can be easily taken. In addition, DAAs are more effective and have less adverse reactions compared to the previously used drugs. Chronic hepatitis C is hard to treat because the virus is error-prone virus. Host immunity is helpless against the hepatitis C virus since it evades the host immunity through various complex mechanisms. There are 6 genotypes. Quasispecies can co-exist even in the same patients. The treatment strategy is based on the combination of the individual drug corresponding to each step of viral replication process. NS5B nucleosides are the most powerful and effective drug available until now. Other drugs with different mechanisms of action can be used to provide synergy. NS5A and NS5B inhibition drugs currently belong to the leading group amongst many DAAs. These drugs will soon be available in Korea. We have to know the merits and adverse drug reactions of the new drug.
Antiviral Agents/*therapeutic use ; Drug Therapy, Combination ; Enzyme Inhibitors/therapeutic use ; Genotype ; Guidelines as Topic ; Hepacivirus/genetics ; Hepatitis C, Chronic/*drug therapy/immunology/virology ; Humans ; Viral Nonstructural Proteins/antagonists & inhibitors/metabolism

Human astrovirus (HastV) is recognized as one of the leading causes of acute viral diarrhea in infants. The HastV non-structural protein, nsPla, and C-terminal protein, nsPla/4, contain various conserved functional domains,and may play an important role in virus replication, transcription and the virus-host interactions of HastV. This study used an E. coli system to investigate the expression of nsPla and nsPla/4 proteins. Firstly,the nsPla and nsPla/4 genes of HAstV-1 were cloned into the prokaryotic expression vector,PGEX-4T-1, to build the PGEX-4T-1a and PGEX-4T-la/4 fusion protein plasmids. Then, the recombinant plasmids were transformed into Escherichia coli BL21 (DE3) and induced with isopropyl-β-D-thiogalactopyranoside (IPTG). The optimal expression conditions of the two fusion proteins were identified and then analyzed by polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting, respectively. The results showed that the pGEX-4T-la fusion protein was maximally expressed at 30 °C after 12 hours of induction with 1.0 mM IPTG. The pGEX-4T-la/4 fusion protein was maximally expressed at 20 °C after 8 hours of induction with 0.5 mM IPTG. Western blot analysis showed that the two fusion proteins specificity reacted with the anti-nsPla and anti-GST monoclonal antibodies, respectively. This study successfully obtained the HAstV non-structural protein, nsP1a, and its C-terminal protein nsP1a/4 protein using an E. coli system. This novel study lays the foundation for future research into the pathogenic mechanisms of human astrovirus and the functions of its non-structural protein.
Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Humans ; Mamastrovirus ; genetics ; metabolism ; Viral Nonstructural Proteins ; genetics ; metabolism

To develop a safe and broad-spectrum effective hepatitis C virus (HCV) T cell vaccine,we constructed the recombinant adenovirus-based vaccine that carried the hepatitis C virus truncated NS3 and core fusion proteins. The expression of the fusion antigen was confirmed by in vitro immunofluorescence and western blotting assays. Our results indicated that this vaccine not only stimulated antigen-specific antibody responses,but also activated strong NS3-specific T cell immune responses. NS3-specific IFN-γ+ and TNF-α+ CD4+ T cell subsets were also detected by a intracellular cytokine secretion assay. In a surrogate challenge assay based on a recombinant heterologous HCV (JFH1,2a) vaccinia virus,the recombinant adenovirus-based vaccine was capable of eliciting effective levels of cross-protection. These findings have im- portant implications for the study of HCV immune protection and the future development of a novel vaccine.
Adenoviridae ; genetics ; metabolism ; Animals ; CD4-Positive T-Lymphocytes ; immunology ; Cross Protection ; Female ; Genetic Vectors ; biosynthesis ; genetics ; Hepacivirus ; genetics ; immunology ; Hepatitis C ; immunology ; prevention & control ; virology ; Humans ; Interferon-gamma ; immunology ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; administration & dosage ; genetics ; immunology ; Viral Core Proteins ; administration & dosage ; genetics ; immunology ; Viral Hepatitis Vaccines ; administration & dosage ; genetics ; immunology ; Viral Nonstructural Proteins ; administration & dosage ; genetics ; immunology

In this study, pEGFP-N1 was chosen as the reporter plasmid and transferred into Ctenopharyngodon idellus kidney (CIK) cells by electroporation, and the optimal electroporation conditions were determined by testing the transfection efficiency with different voltages, pulse times, plasmid amounts, and numbers of shocks. The results showed that the maximum electroporation efficiency was achieved under the following conditions in a 0.2 cm electroporation cuvette containing CIK cells (1.5 x 10(7)/mL, 200 microl): electric voltage 200 V, pulse time 45 ms, plasmid 30 microg, and one electric shock. The total genomic RNA of grass carp reovirus (GCRV) was extracted in this experiment and reversely transcribed into cDNA, which was used to amplify the gene segment of GCRV non-structural protein NS26 using designed specific primers. The PCR product was recombined into pEGFP-N1 vector. The fusion protein EGFP-NS26 was successfully and efficiently expressed in the CIK cells by electroporation, which was confirmed by both fluorescent imaging and Western blot analysis. This experiment laid a foundation for further functional studies of the non-structural protein NS26 of GCRV.
Animals ; Cell Line ; Cyprinidae ; Electroporation ; Fish Diseases ; virology ; Gene Expression ; Kidney ; virology ; Reoviridae ; genetics ; physiology ; Reoviridae Infections ; veterinary ; virology ; Viral Nonstructural Proteins ; genetics ; metabolism