For rapid and accurate screening of recombinant modified vaccinia virus Ankara (rMVA) that satisfied the quality standards of clinical trials, a novel shuttle vector that can delete the marker gene automatically during virus propagation was construted: pZL-EGFP. To construct the pZL-EGFP, the original shuttle vector pSC11 was modified by replacing the LacZ marker gene with enhanced green fluorescent protein (EGFP) and then inserting homologous sequences of TKL into the flank regions of EGFP. Baby hamster kidney (BHK)-21 cells were cotransfected with pZL-EGFP and MVA, and underwent ten passages and one plaque screening to obtain the EGFP-free rMVA carrying the exogenous gene. Resulting rMVA was tested by polymerase chain reaction and western blotting to verify pZL-EGFP function. A novel shuttle vector pZL-EGFP containing an EGFP marker gene which could be deleted automatically was constructed. This gene deletion had no effect on the activities of rMVA, and the exogenous gene could be expressed stably. These results suggest that rMVA can be packaged efficiently by homologous recombination between pZL-EGFP and MVA in BHK-21 cells, and that the carried EGFP gene can be removed automatically by intramolecular homologous recombination during virus passage. Meanwhile, the gene deletion had no influence on the activities of rMVA and the expression of exogenous target gene. This study lays a solid foundation for the future research.
Animals ; Biomarkers ; Cricetinae ; Epithelial Cells ; virology ; Gene Deletion ; Genetic Engineering ; methods ; Genetic Vectors ; genetics ; metabolism ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Recombination, Genetic ; Vaccinia ; virology ; Vaccinia virus ; genetics ; physiology ; Virus Replication

To optimize the immunization strategy against HIV-1, a DNA vaccine was combined with a recombinant vaccinia virus (rTV) vaccine and a protein vaccine. Immune responses against HIV-1 were detected in 30 female guinea pigs divided into six groups. Three groups of guinea pigs were primed with HIV-1 DNA vaccine three times, boosted with rTV at week 14, and then boosted with gp140 protein at intervals of 4, 8 or 12 weeks. Simultaneously, the other three groups of animals were primed with rTV vaccine once, and then boosted with gp140 after 4, 8 or 12 weeks. The HIV-1 specific binding antibody and neutralizing antibody, in addition to the relative affinity of these antibodies, were detected at different time points after the final administration of vaccine in each group. The DNA-rTV-gp140 immune regimen induced higher titers and affinity levels of HIV-1 gp120/gp140 antibodies and stronger V1V2-gp70 antibodies than the rTV-gp140 regimen. In the guinea pigs that underwent the DNA-rTV-gp140 regimen, the highest V1V2-gp70 antibody was induced in the 12-week-interval group. However, the avidity of antibodies was improved in the 4-week-interval group. Using the rTV-gp140 immunization strategy, guinea pigs boosted at 8 or 12 weeks after rTV priming elicited stronger humoral responses than those boosted at 4 weeks after priming. In conclusion, this study shows that the immunization strategy of HIV-1 DNA vaccine priming, followed by rTV and protein vaccine boosting, could strengthen the humoral response against HIV-1. Longer intervals were better to induce V1V2-gp70-specific antibodies, while shorter intervals were more beneficial to enhance the avidity of antibodies.
AIDS Vaccines ; administration & dosage ; genetics ; immunology ; Animals ; DNA, Viral ; administration & dosage ; genetics ; immunology ; Female ; Guinea Pigs ; HIV Infections ; immunology ; prevention & control ; virology ; HIV-1 ; genetics ; immunology ; Humans ; Immunization ; methods ; Vaccines, DNA ; administration & dosage ; genetics ; immunology ; Vaccinia virus ; genetics ; immunology ; env Gene Products, Human Immunodeficiency Virus ; administration & dosage ; genetics ; immunology

Orthopoxvirus vector has a broad prospect in recombinant vaccine research, but the rarely severe side-effect impedes its development. Vaccinia virus and Cowpox virus of Orthopoxvirus have broad host range, and they have typical host range genes as K1L, CP77 and C7L. These three genes affect host range of Vaccinia virus, disturb the cell signaling pathways, suppress immune response and are related to virulence.
Cell Line ; Cowpox virus ; genetics ; immunology ; pathogenicity ; physiology ; Genetic Vectors ; Host Specificity ; genetics ; Orthopoxvirus ; genetics ; immunology ; pathogenicity ; physiology ; Signal Transduction ; Vaccines, Synthetic ; immunology ; Vaccinia virus ; genetics ; immunology ; pathogenicity ; physiology ; Viral Proteins ; genetics ; metabolism ; Viral Vaccines ; immunology ; Virulence

A recombinant modified vaccinia Ankara (MVA) virus expressing mature viral protein 2 (VP2) of the infectious bursal disease virus (IBDV) was constructed to develop MVA-based vaccines for poultry. We demonstrated that this recombinant virus was able to induce a specific immune response by observing the production of anti-IBDV-seroneutralizing antibodies in specific pathogen-free chickens. Besides, as the epitopes of VP2 responsible to induce IBDV-neutralizing antibodies are discontinuous, our results suggest that VP2 protein expressed from MVA-VP2 maintained the correct conformational structure. To our knowledge, this is the first report on the usefulness of MVA-based vectors for developing recombinant vaccines for poultry.
Animals ; Antibodies, Viral ; Birnaviridae Infections/prevention & control/*veterinary ; Cells, Cultured ; Chick Embryo ; Chickens ; Fibroblasts/metabolism ; Infectious bursal disease virus/*immunology ; Poultry Diseases/*prevention & control/virology ; Specific Pathogen-Free Organisms ; Vaccinia virus/*genetics/immunology/metabolism ; Viral Structural Proteins/genetics/*immunology/metabolism ; Viral Vaccines/*immunology

The spike (S) glycoprotein of HCoV-NL63 is a major target in the development of diagnostic assays and vaccines, but its antigenic and immunogenic properties remain unclear. Four fragments coding spike proteins (S1, S2, RL and RS) from HCoV-NL63 were amplified and cloned into the expression vector derived from vaccinia virus (Tiantan strain), and recombinant vaccinia viruses expressing four segments of spike proteins were generated (vJSC1175-S1; vJSC1175-S2; vJSC1175-RL; vJSC1175-RS), respectively. Their expression location in cell and level were characterized using indirect immune fluorescence assay (IFA) and Western-Blot, respectively. The expressions of four segments of spike proteins in recombinant vaccinia viruses were showed at appropriate level and with posttranslational modification (glycosylation), and S1, RL and RS were mainly distributed in the cell membrane, while the S2 was mainly distributed in the cytoplasm. Our results provide a basis for further exploring diagnostic role and vaccine development of different spike segments from HCoV-NL63.
Base Sequence ; Blotting, Western ; Coronavirus NL63, Human ; chemistry ; Fluorescent Antibody Technique, Indirect ; Humans ; Membrane Glycoproteins ; biosynthesis ; genetics ; Molecular Sequence Data ; Plasmids ; Recombinant Proteins ; biosynthesis ; Spike Glycoprotein, Coronavirus ; Vaccinia virus ; genetics ; Viral Envelope Proteins ; biosynthesis ; genetics

To investigate the genetic stability (including the vector of vaccinia virus and six foreign genes: gp160, gag, pol, rev, tat and nef) of the HIV-1 non-replicating recombinant vaccinia virus (rNTV-C). rNTV-C was serially passaged to passage 25 (P25) in primary chicken embryo fibroblast (CEF). P9, P12, P15 and P25 were selected to study the genetic stability in four aspects, including the genetic stability of viral vector, the genetic stability of six foreign genes, the expressing stability of foreign genes and the genetic loss of foreign genes. The results showed that the viral vector was non-replicated vaccinia virus of Tiantan strain and was passaged stably; foreign gene sequences matched with designed sequences, the insert sites were right, and the nucleotide mutation rate was less than one over ten thousands within different passages of rNTV-C; the target proteins could be expressed effectively, and the expression level was stable within different passages of rNTV-C; the genetic loss of gag and nef was less than 5% within different passages of rNTV-C. The above results provided important data for the vaccine production.
Animals ; DNA, Recombinant ; genetics ; Fibroblasts ; metabolism ; virology ; Gene Expression ; Genes, Viral ; genetics ; Genetic Engineering ; methods ; Genetic Vectors ; genetics ; HIV-1 ; genetics ; Sequence Analysis, DNA ; Vaccinia virus ; genetics

UNLABELLEDA novel double expression shuttle vector named pLR-gpt was constructed for marker-free recombinant modified vaccinia virus Ankara generation. A delectable Eco gpt marker was adopted with Cre/LoxP DNA recombination system and a BHK-21 cell line that can express Cre enzyme. Eco gpt gene controlled by P7.5 promoter from Vaccinia virus was cloned between two LoxP sites in the same direction. Additionally, two multiple cloning site under control of other two Vaccinia virus promoters were constructed outside LoxP sites. With this new transfer vector, Eco gpt marker in rMVA can be deleted on BHK-Cre with interaction between Cre enzyme and LoxP sequence. In order to verify the efficacy of this system, ORF5 and ORF6 gene of Porcine reproductive and respiratory syndrome virus (PRRSV) NJ-a strain were cloned into two multiple cloning sites of pLR-gpt to construct recombinant plasmid pLR-ORFS/ORF6. Homologous recombination between pLR-ORF5/ORF6 and wtMVA on BHK-21 cell was mediated by liposome by infecting cells with 0.01 MOI wtMVA two hours before transfection. After twelve cycles of selection, recombinant MVA with selecting marker Eco gpt was obtained and named as rMVAgpt-GP5/M. By infecting BHK-Cre, the Eco gpt marker in rMVAgpt-GP5/M was deleted and this rMVA was named as rMVA-GP5/M. Expression of GP5 and M protein was identified with Western blotting and IFA. Results from PCR and biological study for rMVA indicated that Eco gpt marker was completely deleted.

CONCLUSIONSdouble expression transfer vector for marker-free recombinant Modified vaccinia virus Ankara generation was successfully constructed, and works well in MVA expression system.

Cell Line ; Cloning, Molecular ; DNA, Recombinant ; genetics ; Escherichia coli Proteins ; genetics ; Genetic Vectors ; genetics ; Pentosyltransferases ; genetics ; Porcine respiratory and reproductive syndrome virus ; genetics ; Vaccinia virus ; genetics ; Viral Envelope Proteins ; genetics ; Viral Matrix Proteins ; genetics

This study aimed to develop an effective experimental vaccine against highly pathogenic H5N1 Avian Influenza (HPAI) virus and to optimize their immunization programs. As reported previously, various DNA-based or recombinant vaccinia viral(Tiantan)-based H5N1 vaccine candidates, which containing a single cistronic construct (HAop, or NAop) or a bicistronic construct (HAop/M2 or NAop/M1) of H5N1 influenza virus (Anhui strain) were constructed and characterized in our lab. In this study, we further analysed the immunogenicity in mice of these vaccine candidates by various protocols (single or combined immunization). Our results showed that: comparing with immunization with DNA-based or rTTV-based H5N1 vaccine only, combined DNA-based with rTTV-based H5N1 vaccine immunization via prime-boost strategy enhanced immune response significantly against multi-H5N1 antigens detected by hemagglutination inhibition (HI) assay, NA- or M1- or M2-specific antibody detection, and micro-neutralizing antibody test and IFN-gamma ELISpot assay. Priming with DNA-based vaccine induced higher level of humoral response against HA or NA antigen than priming with rTTV-based vaccine; In contract, M1 and M2-specific antibody levels were higher among that of priming with rTTV -based vaccine. These findings provide a basis for further development of novel H5N1 vaccines and for the optimization of the immunization programs of combined multi-antigens vaccine candidates.
Animals ; Antigens, Viral ; genetics ; immunology ; Female ; Immunization ; methods ; Influenza A Virus, H5N1 Subtype ; genetics ; immunology ; Influenza Vaccines ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Vaccination ; methods ; Vaccines, DNA ; genetics ; immunology ; Vaccines, Synthetic ; genetics ; immunology ; Vaccinia ; genetics ; immunology

BACKGROUND/AIMS: JX-594 is an oncolytic virus derived from the Wyeth vaccinia strain that causes replication-dependent cytolysis and antitumor immunity. Starting with a cross-examination of clinical-trial samples from advanced hepatocellular carcinoma patients having high levels of aldosterone and virus amplification in JX-594 treatment, we investigated the association between virus amplification and aldosterone in human cancer cell lines. METHODS: Cell proliferation was determined by a cell-counting-kit-based colorimetric assay, and vaccinia virus quantitation was performed by quantitative polymerase chain reaction (qPCR) and a viral plaque assay. Also, the intracellular pH was measured using a pH-sensitive dye. RESULTS: Simultaneous treatment with JX-594 and aldosterone significantly increased viral replication in A2780, PC-3, and HepG2 cell lines, but not in U2OS cell lines. Furthermore, the aldosterone treatment time altered the JX-594 replication according to the cell line. The JX-594 replication peaked after 48 and 24 hours of treatment in PC-3 and HepG2 cells, respectively. qPCR showed that JX-594 entry across the plasma membrane was increased, however, the changes are not significant by the treatment. This was inhibited by treatment with spironolactone (an aldosterone-receptor inhibitor). JX-594 entry was significantly decreased by treatment with EIPA [5-(N-ethyl-N-isopropyl)amiloride; a Na+/H+-exchange inhibitor], but aldosterone significantly restored JX-594 entry even in the presence of EIPA. Intracellular alkalization was observed after aldosterone treatment but was acidified by EIPA treatment. CONCLUSIONS: Aldosterone stimulates JX-594 amplification via increased virus entry by affecting the H+ gradient.
Aldosterone/*pharmacology ; Aldosterone Antagonists/pharmacology ; Amiloride/analogs & derivatives/pharmacology ; Animals ; Carcinoma, Hepatocellular/blood/virology ; Cell Line, Tumor ; Humans ; Hydrocortisone/blood ; Hydrogen-Ion Concentration ; Liver Neoplasms/blood/virology ; Neuroprotective Agents/pharmacology ; Oncolytic Virotherapy ; Rabbits ; Spironolactone/pharmacology ; Vaccinia virus/*drug effects/genetics/metabolism/*physiology ; Virus Replication/*drug effects

Vaccinia virus complement control protein (VCP) is one of the proteins encoded by vaccinia virus to modulate the host inflammatory response. VCP modulates the inflammatory response and protects viral habitat by inhibiting the classical and the alternative pathways of complement activation. The extended structure of VCP, mobility between its sequential domains, charge distribution and type of residues at the binding regions are factors that have been identified to influence its ability to bind to complement proteins. We report that a Lister strain of vaccinia virus encodes a VCP homolog (Lis VCP) that is functional, glycosylated, has two amino acids less than the well-characterized VCP from vaccinia virus WR strain (WR VCP), and the human smallpox inhibitor of complement enzymes (SPICE) from variola virus. The glycosylated VCP of Lister is immunogenic in contrast to the weak immunogenicity of the nonglycosylated VCP. Lis VCP is the only orthopoxviral VCP homolog found to be glycosylated, and we speculate that glycosylation influences its pattern of complement inhibition. We also correlate dimerization of VCP observed only in mammalian and baculovirus expression systems to higher levels of activity than monomers, observed in the yeast expression system.
Amino Acid Sequence ; Animals ; Cell Line ; Cercopithecus aethiops ; Complement Activation ; drug effects ; immunology ; Complement System Proteins ; metabolism ; Dimerization ; Gene Expression ; Glycosylation ; Humans ; Molecular Sequence Data ; Protein Binding ; Protein Structure, Tertiary ; Recombinant Proteins ; genetics ; metabolism ; Smallpox ; immunology ; metabolism ; Structure-Activity Relationship ; Vaccinia virus ; chemistry ; immunology ; metabolism ; Variola virus ; chemistry ; immunology ; metabolism ; Viral Proteins ; genetics ; metabolism ; pharmacology