Bombyx mori nucleopolyhedrovirus (BmNPV) bm47 gene is found in all sequenced lepidopteran nucleopolyhedroviruses (NPVs). It is one of the core genes of NPVs. However, the role of bm47 in the biological cycle of NPV remains unknown. In this study, the Red recombination system was used to knock out bm47 from BmNPV to construct bm47-ko-Bacmid in E. coli BW25113 system. Then bm47 gene was introduced back to the viral genome using the Bac-to-Bac system to create the repair virus bm47-re-Bacmid. TCID50 assay and real-time PCR (qPCR) were used to evaluate the effects of bm47 deletion on viral DNA replication, gene transcription, and protein expression. qPCR results showed that bm47 knock-out had no significant effect on viral DNA replication. However, the qPCR results showed that bm47-ko-Bacmid significantly decreased the transcription levels of early gene lef-3, late gene vp39, and very late gene p10 at 48 h and 72 h after viral transfection of BmN cells (P < 0.05). This work will provide a foundation for further studies on the biological function of BmNPV bm47 in viral replication and transcription.
Animals ; Bombyx ; virology ; Gene Deletion ; Gene Expression Regulation, Viral ; Nucleopolyhedrovirus ; genetics ; physiology ; Transcription, Genetic ; Viral Proteins ; genetics ; metabolism ; Virus Replication

Coxsackievirus Infections ; immunology ; virology ; Enterovirus A, Human ; physiology ; Enterovirus Infections ; immunology ; virology ; Gene Expression Regulation ; immunology ; Gene Expression Regulation, Viral ; Host-Pathogen Interactions ; immunology ; Humans

The oncogenic Epstein-Barr virus (EBV) -encoded latent membrane protein 1 (LMP1) enables this virus's long-term survival within the cells of immune system. Mean while, LMP1 also plays a critical role for the transformation of resting B cells by EBV. It initiates the activation of signalling pathways, such as NF-kappaB, mitogen-activated protein kinase (MAPK), and JAK/STAT cascade by adaptor proteins including the tumor necrosis factor (TNF) receptor associated factors (TRAFs) and the TNF receptor associated death domain protein (TRADD). It increases the expression of adhesion molecules LFA-1, ICAM-1, and costimulatory molecule B7-1 of B cells, and regulates the antibody and cytokine secreted by B cells. LMP1 and CD40 have many common properties in signal transduction. Both of them co-localize in lipid rafts for signal transduction. Considering its close relationship with CD40, the research on LMP1 has become a hot spot in the immunology field.
Animals ; B-Lymphocytes ; immunology ; CD40 Antigens ; genetics ; physiology ; Gene Expression Regulation, Viral ; Herpesvirus 4, Human ; genetics ; metabolism ; physiology ; Humans ; Signal Transduction ; Viral Matrix Proteins ; genetics ; physiology

Antigens, Viral ; genetics ; metabolism ; Cell Line ; Cell Phone ; Gene Expression Regulation, Viral ; radiation effects ; Herpesvirus 4, Human ; physiology ; radiation effects ; Humans ; Immunohistochemistry ; Viral Proteins ; genetics ; metabolism

OBJECTIVETo screen the gene expression profiles of IFN-alpha antiviral proteins based on a low-density cDNA Macroarray, and to explore the relationship between the expression of antiviral protein and the HBV replication.

METHODSThe HepG2 and HepG2.2.15 cells were treated with various concentrations of IFN-alpha (0 IU/ml, 100 IU/ml, 1000 IU/ml) of IFN-alpha for 6 h, and then the low-density cDNA Macroarray was used for analysing the expression profiles of antiviral genes and screening differential expressions of antiviral proteins. Meanwhile, the HepG2 cells were transiently transfected with HBV core protein-expressed plasmid pHBc-EGFP, and the expressions of antiviral proteins were analysed by RT-PCR assay. Moreover, the HepG2.2.15 cells were also transfected with the antiviral protein-expressed plasmid pcDNA3.1-Flag-MxA. ELISA was used for analysing the secreted HBV antigens, while dot blot and Southern blot were applied for analysing the extracellular HBV DNA and intracellular replicative intermediate HBV DNA in HepG2.2.15 cells. All data were presented as mean+/-SD and analyzed using the t-test and one-way analysis of variance (ANOVA) in the experiments.

RESULTSThe Macroarray results suggested that the expression of IFN-alpha antiviral genes like 6-16, IFITM1, IFITM2, IFITM3 and RING4 in HepG2.2.15 cells were partially inhibited. More importantly, it was found, in this research, the expression of antiviral protein MxA in HepG2.2.15 cells was completely suppressed. RT-PCR analysis indicated that the expression of MxA was also significantly decreased in HepG2 cells transfected with pHBc-EGFP plasmid. Although HepG2.2.15 cells transfected with pcDNA3.1-Flag-MxA plasmid could not inhibit extracellular HBV DNA and intracellular replicative intermediate HBV DNA, the MxA exerted some antiviral activities as it effectively suppressed the secretion of HBsAg and HBeAg in HepG2.2.15 cells.

CONCLUSIONSHBV and its antigen components probably influence the expression of antiviral proteins. IFN- resistance may be related to the down-regulation of antiviral proteins expression.

Antiviral Agents ; pharmacology ; Gene Expression Profiling ; Gene Expression Regulation, Viral ; Hep G2 Cells ; Hepatitis B virus ; drug effects ; physiology ; Humans ; Interferon-alpha ; pharmacology ; Plasmids

Porcine endogenous retroviruses (PERVs) are members of family Retroviridae, genus Gamma retrovirus, and transmitted by both horizontally and vertically like other endogenous retroviruses (ERVs). PERV was initially described in the 1970s having inserted its gene in the host genome of different pig breeds, and three classes, PERV-A, PERV-B, and PERV-C are known. The therapeutic use of living cells, tissues, and organs from animals called xenotransplantation might relieve the limited supply of allografts in the treatment of organ dysfunction. Because of ethical considerations, compatible organ sizes, and physiology, the pig has been regarded as an alternative source for xenotransplantation. Sensitive duplex reverse transcription-polymerase chain reaction protocols for simultaneously detecting PERV gag mRNA and porcine glyceraldehydes 3-phosphate dehydrogenase mRNA in one tube was established. To compare the age-related PERV expression patterns of the lung, liver, spleen, kidney, heart, and pancreas in commercial pigs, 20 pigs from four age groups (5 heads each in 10 days-, 40 days-, 70 days-, and 110 days-old, respectively) were used in this study. The expression patterns of PERV were statistically different among age groups in lung, liver, and kidney (ANOVA, p<0.05). These data may support in the selection of appropriate donor pigs expressing low levels of PERV mRNA.
Animals ; Endogenous Retroviruses/*metabolism ; Gene Expression Regulation, Viral/*physiology ; RNA, Messenger/genetics/metabolism ; RNA, Viral/genetics/metabolism ; Reverse Transcriptase Polymerase Chain Reaction/methods/*veterinary ; Sensitivity and Specificity ; Swine/*virology

OBJECTIVETo gain some insights into the critical events relating to HBV transcriptional regulation by comparing HBV replicative characteristics in different cell lines.

METHODSHepatic cell lines QSG-7701 and HepG2 were transfected with plasmid PUC18-HBV 1.2 by standard calcium phosphate precipitation method, and 1.0 microg pSEAP2-control vector was included in the transfection procedures to serve as an internal control monitoring the transfection efficiency. Hepatitis B surface antigen (HBsAg) in the medium was detected by ELISA method and HBV DNA was quantitated using fluorescent quantitative PCR. The intracellular HBsAg and HBcAg were detected with immunofluorescent staining. The gene expression profiles of QSG-7701 and HepG2 were compared using oligonucleotide microarray; partial differentially expressed genes were verified with quantitative RT-PCR.

RESULTSIn the medium of the cultured HepG2 cells, HBsAg and HBV DNA could be detected 6 days after the transfection, whereas in QSG-7701 cells, the HBsAg and HBV DNA could be detected for 2 weeks. The HBV DNA in the culture medium of QSG-7701 was about 50 times more than that of the HepG2 cells which were kept in 1 x 10(7)copies/ml(-3) x 10(7)copies/ml for 0 to 10 days after the transfection. On the 4th day after the transfection, 20% to 30% of the QSG-7701 cells were positive with HBsAg and HBcAg immunofluorescent staining. The gene microarray analysis showed that most transcription factors involved with HBV life cycle in QSG-7701 and HepG2 cells had similar levels, whereas some factors involved with HBV transcriptional regulation and core particle disassembly, such as interleukin-6 (R=5.1340), retinoid X receptor, alpha (R=5.1268), hepatic leukemia factor (R=3.2538), serine protease PRRS23 (R=2.8356), hepatitis B virus x interacting protein (R=0.4939), serine protease inhibitor Kazal type 1 (R=0.0740) and matrix metalloproteinase 3 (negative in QSG-7701) were all differentially expressed by HepG2 cells.

CONCLUSIONDifferent than HepG2 cells, the QSG-7701 cells could support a high level and relatively stable HBV replication after HBV DNA transient transfection. The HBV core particles were probably recycled in the QSG-7701 cells. The differential gene expressions between QSG-7701 and HepG2 might explain the mechanism of the different HBV replication patterns. Hepatic cell line QSG-7701 might serve as a useful tool for HBV transcriptional regulation research.

Cell Line ; Gene Expression Regulation, Viral ; Genetic Vectors ; Genome, Viral ; Hep G2 Cells ; Hepatitis B virus ; genetics ; physiology ; Humans ; Virus Replication

Animals ; Cloning, Molecular ; DNA Replication ; DNA, Viral ; genetics ; Gene Expression Regulation, Viral ; Hepatitis B virus ; genetics ; metabolism ; physiology ; Humans ; Trans-Activators ; genetics ; Virus Replication

Treatment of bovine mastitis caused by Staphylococcus (S.) aureus is becoming very difficult due to the emergence of multidrug-resistant strains. Hence, the search for novel therapeutic alternatives has become of great importance. Consequently, bacteriophages and their endolysins have been identified as potential therapeutic alternatives to antibiotic therapy against S. aureus. In the present study, the gene encoding lysin (LysSA4) in S. aureus phage SA4 was cloned and the nucleotide sequence was determined. Sequence analysis of the recombinant clone revealed a single 802-bp open reading frame encoding a partial protein with a calculated mass of 30 kDa. Results of this analysis also indicated that the LysSA4 sequence shared a high homology with endolysin of the GH15 phage and other reported phages. The LysSA4 gene of the SA4 phage was subsequently expressed in Escherichia coli. Recombinant LysSA4 induced the lysis of host bacteria in a spot inoculation test, indicating that the protein was expressed and functionally active. Furthermore, recombinant lysin was found to have lytic activity, albeit a low level, against mastitogenic Staphylococcus isolates of bovine origin. Data from the current study can be used to develop therapeutic tools for treating diseases caused by drug-resistant S. aureus strains.
Animals ; Base Sequence ; Cloning, Molecular ; Gene Expression Regulation, Viral/physiology ; Mucoproteins/genetics/*metabolism ; Phylogeny ; Polymerase Chain Reaction/methods ; Recombinant Proteins ; Staphylococcus Phages/genetics/*metabolism/physiology ; Staphylococcus aureus/*virology

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