Transient expression is the major method to express foot-and-mouth disease virus (FMDV) capsid proteins in mammalian cells. To achieve stable expression of FMDV capsid proteins and efficient assembly of virus like particles (VLPs) in cells, the plasmids of piggyBac (PB) transposon-constitutive expression and PB transposon-tetracycline (Tet) inducible expression vectors were constructed. The function of the plasmids was tested by fluorescent proteins. By adding antibiotics, the constitutive cell pools (C-WT, C-L127P) expressing P12A3C (WT/L127P) genes and the inducible cell pools (I-WT, I-L127P) expressing P12A3C (WT/L127P) genes were generated. The genes of green fluorescent protein, 3C protease and reverse tetracycline transactivator (rtTA) were integrated into chromosome, which was confirmed by fluorescence observation and PCR testing. The cell pool I-L127P has a stronger production capacity of capsid proteins and VLPs, which was confirmed by Western blotting and enzyme linked immunosorbent assay (ELISA), respectively. In conclusion, inducing the chromosomal expression of FMDV capsid proteins was firstly reported, which may facilitate the technical process of mammalian production of FMDV VLPs vaccine and the construction of mammalian inducible expression systems for other proteins.
Animals ; Foot-and-Mouth Disease Virus/genetics* ; Capsid Proteins ; Viral Proteins/metabolism* ; Foot-and-Mouth Disease/prevention & control* ; Tetracyclines/metabolism* ; Viral Vaccines ; Antibodies, Viral ; Mammals/metabolism*

In order to construct a recombinant replication deficient human type 5 adenovirus (Ad5) expressing a foot-and-mouth disease virus (FMDV) capsid protein, specific primers for P12A and 3B3C genes of FMDV-OZK93 were synthesized. The P12A and 3B3C genes were then amplified and connected by fusion PCR, and a recombinant shuttle plasmid pDC316-mCMV-EGFP-P12A3B3C expressing the FMDV-OZK93 capsid protein precursor P12A and 3B3C protease were obtained by inserting the P12A3B3C gene into the pDC316-mCMV-EGFP plasmid. The recombinant adenovirus rAdv-P12A3B3C-OZK93 was subsequently packaged, characterized and amplified using AdMax^TM adenovirus packaging system, and the expression was verified by infecting human embryonic kidney cell HEK-293. The humoral and cellular immunity levels of well-expressed and purified recombinant adenovirus immunized mice were evaluated. The results showed that rAdv-P12A3B3C-OZK93 could be stably passaged and the maximum virus titer reached 1×10^9.1 TCID₅₀/mL. Western blotting and indirect immunofluorescence showed that rAdv-P12A3B3C-OZK93 expressed the FMDV-specific proteins P12A and VP1 in HEK-293 cells. In addition, the PK cell infection experiment confirmed that rAdv-P12A3B3C-OZK93 could infect porcine cells, which is essential for vaccination in pigs. Comparing with the inactivated vaccine group, the recombinant adenovirus could induce higher FMDV-specific IgG antibodies, γ-IFN and IL-10. This indicates that the recombinant adenovirus has good immunity for animal, which is very important for the subsequent development of foot-and-mouth disease vaccine.
Adenoviridae/genetics* ; Adenoviruses, Human/genetics* ; Animals ; Antibodies, Viral ; Capsid/metabolism* ; Capsid Proteins ; Foot-and-Mouth Disease/prevention & control* ; Foot-and-Mouth Disease Virus/genetics* ; HEK293 Cells ; Humans ; Mice ; Recombinant Proteins/genetics* ; Serogroup ; Swine ; Viral Proteins ; Viral Vaccines/genetics*

In order to develop a combined live vaccine that will be used to prevent against porcine parvovirus (PPV) and Pseudorabies virus (PRV) infection, the VP2 gene of PPV was inserted into the transfer vector plasmid pG to produce the recombinant plasmid pGVP2. The plasmid pGVP2 and the genome of PRV HB98 attenuated vaccine were transfected by using lipofectamine into swine testis cells for the homologous recombination. The recombinant virus rPRV-VP2 was purified by selection of green fluorescence plaques for five cycles. 6-week-old female Kunming mice were immunized intramuscularly with attenuated PRV parent HB98 strain, commercial inactivated vaccine against PPV, recombinant virus, DMEM culture solution. The injections were repeated with an equivalent dose after 2 weeks in all of the groups, and then challenged with the virulent PRV NY strain at 7 weeks after the first immunization. The recombinant virus rPRV-VP2 was successfully generated, and the recombinant virus could effectively elicite anti-PPV and PRV antibody and significant cellular immune response as indicated by anti-PPV ELISA and HI, PRV-neutralizing assay and flow cytometry. The challenge assay indicated that recombinant virus could protect the mice against the virulent PRV challenge. These results demonstrated that the recombinant virus can be a candidate recombinant vaccine strain for the prevention of PRV and PPV.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; administration & dosage ; genetics ; immunology ; Capsid Proteins ; administration & dosage ; genetics ; immunology ; Female ; Gene Expression ; Genetic Vectors ; genetics ; metabolism ; Herpesvirus 1, Suid ; genetics ; metabolism ; Mice ; Parvovirus, Porcine ; genetics ; immunology ; Swine ; Swine Diseases ; immunology ; prevention & control ; virology ; Viral Vaccines ; administration & dosage ; genetics ; immunology

Recombinant gene expression using adeno-associated viruses (AAVs) has become a valuable tool in animal studies, as they mediate safe expression of transduced genes for several months. The liver is a major organ of metabolism, and liver-specific expression of a gene can be an invaluable tool for metabolic studies. AAV-DJ is a recombinant AAV generated by the gene shuffling of various AAV serotypes and shares characteristics of AAV2 and AAV8. AAV-DJ contains a heparin-binding domain in its capsid, which suggests that a heparin column could be used for the purification of the AAV. Given that AAV-DJ has been only recently available, relatively little is known about the optimal preparation/purification and application of AAV-DJ. Here, we present a simple large-scale preparation method that can generate 3×10(13) viral particles for in vivo experiments and demonstrate liver-specific gene expression via systemic injection in mice.
Animals ; Capsid ; Capsid Proteins/*genetics ; Dependovirus/*genetics ; *Gene Expression ; *Genetic Vectors ; Genome, Viral/genetics ; Hep G2 Cells ; Humans ; Liver/*metabolism ; Mice ; Mice, Inbred C57BL

BACKGROUND: The incidence and etiology of hepatocellular carcinoma (HCC) vary widely according to race and geographic regions. The insertional mutagenesis of adeno-associated virus 2 (AAV2) has recently been considered a new viral etiology of HCC. The aim of this study was to investigate the frequency and clinical characteristics of AAV2 in Korean patients with HCC. METHODS: A total of 289 unrelated Korean patients with HCC, including 159 Hepatitis-B-related cases, 16 Hepatitis-C-related cases, and 114 viral serology-negative cases, who underwent surgery at the Samsung Medical Center in Korea from 2009 to 2014 were enrolled in this study. The presence of AAV2 in fresh-frozen tumor tissues was investigated by DNA PCR and Sanger sequencing. The clinical and pathological characteristics of AAV2-associated HCC in these patients were compared with previous findings in French patients. RESULTS: The AAV2 detection rate in Korean patients (2/289) was very low compared with that in French patients (11/193). Similar to the French patients, the Korean patients with AAV2-related HCC showed no signs of liver cirrhosis. The Korean patients were younger than the French patients with the same AAV2-associated HCC; the ages at diagnosis of the two Korean patients were 47 and 39 yr, while the median age of the 11 French patients was 55 yr (range 43-90 yr). CONCLUSIONS: AAV2-associated HCC was very rare in Korean patients with HCC. Despite a limited number of cases, this study is the first to report the clinical characteristics of Korean patients with AAV2-associated HCC. These findings suggest epidemiologic differences in viral hepatocarcinogenesis between Korean and European patients.
Adult ; Asian Continental Ancestry Group ; Capsid Proteins/genetics ; Carcinoma, Hepatocellular/etiology/*pathology/virology ; DNA, Viral/chemistry/genetics/metabolism ; DNA-Binding Proteins/genetics ; Dependovirus/*genetics/isolation & purification/pathogenicity ; Female ; Humans ; Incidence ; Inverted Repeat Sequences/genetics ; Liver Neoplasms/etiology/*pathology/virology ; Male ; Middle Aged ; Parvoviridae Infections/complications/epidemiology ; Polymerase Chain Reaction ; Republic of Korea ; Sequence Analysis, DNA ; Viral Proteins/genetics

To construct a bait expression vector containing the duck circovirus Cap gene for use in the yeast two-hybrid system, the whole cap codon-optimized gene was inserted into pGBKT7 vector and confirmed by PCR, restriction enzyme digestion, and sequence analysis. After transformation into a Y2HGold yeast strain, the expression of Cap protein was analyzed by Western blotting. Toxicity and self-activation of the bait protein were detected using different dropout minimal base. PCR reaction, restriction enzyme digestion, and sequencing analyses indicated that the duck circovirus Cap gene was correctly inserted into pG- BKT7. Western blotting showed that the whole Cap protein was expressed. The recombinant bait protein had no toxicity and self-activation. Therefore, the bait vector with the Cap gene was constructed successfully, providing a foundation for future screening for interacting proteins in the yeast two-hybrid system.
Animals ; Capsid Proteins ; genetics ; metabolism ; Circovirus ; classification ; genetics ; isolation & purification ; Cloning, Molecular ; Ducks ; Genetic Vectors ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism ; Saccharomyces cerevisiae ; genetics ; metabolism ; Two-Hybrid System Techniques

The World Health Organization redefined the type 2 vaccine-derived poliovirus (VDPV) in 2010. To study the genetic characteristics and evolution of type 2 VDPV under this new definition, we conducted genome sequencing and analyses of type 2 VDPVs isolated from one patient with acute flaccid paralysis in Shanxi province (China) in 2014. Nucleotide sequencing revealed that the full-length of type 2 VDPV is 7439 bases encoding 2207 amino acids with no insertion or deletion of nucleotides compared with Sabin2. One nucleotide substitution identified as a key determinant of the attenuated phenotype of the Sabin 2 strain (A-G reversion at nucleotide nt 481 in the 5-end of the untranslated region) had reverted in the Shanxi type 2 VDPV. The other known key determinant of the attenuated phenotype of the Sabin 2 strain (U-->C reversion at nt2909 in the VP1 coding region that caused a Ile143Thr substitution in VP1) had not reverted in the Shanxi VDPV. The Shanxi type 2 VDPV was S2/S1 recombinant, the crossover site of which mapped to the 3-end of the 3D region (between nt 6247 and nt 6281). A phylogentic tree based on the VP1 coding region showed that evolution of the Shanxi type 2 VDPV was independent of other type 2 VDPVs detected worldwide. We estimated that the strain circulated for approximately = 11 months in the population according to the known evolution rate. The present study confirmed that the Chinese Polio Laboratory Network could discover the VDPV promptly and that it played an important part in maintenance of a polio-free China.
Amino Acid Sequence ; Base Sequence ; Capsid Proteins ; chemistry ; genetics ; China ; Humans ; Infant ; Male ; Molecular Sequence Data ; Phylogeny ; Poliomyelitis ; virology ; Poliovirus ; chemistry ; genetics ; metabolism ; Poliovirus Vaccines ; adverse effects ; chemistry ; genetics ; metabolism ; Sequence Alignment

Porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) are very two important pathogens that have coursed huge economic losses in swine production in worldwide. In this study,a vector pCMV-TJM containing the full-length cDNA clone of PRRSV attenuated strain TJM-F92 was firstly constructed by PCR method. Then a gene sequence containing Afl II/Mlu I e restriction enzyme sites and a transcription regulatory sequence for ORF6 (TRS6) was inserted be- tween ORF7 and 3'UTR, yielding a expression vector pCMV-TJM-TRS. Subsequently, a plasmid pCMV-TJM-Cap was constructed by cloning of PCV2 ORF2 gene into the unique sites Afl II /Mlu I of pCMV- TJM-TRS plasmid DNA. Then three recombinant PRRSV, rTJM, rTJM/TRS and rTJM/Cap, were rescued by transfection of pCMV-TJM, pCMV-TJM-TRS and pCMV-TJM-Cap into Marc-145 cells, respectively,and confirmed by the genome sequence, restriction enzyme digestion, Western Blot and IFA. They all had the molecular markers which was different from the parent virus. The growth characteristics of the rescued viruses were similar to that of parent virus. rTJM/Cap could also express efficiently PCV2 Cap protein in Marc-145 cells. At passage 8, it still had PCV2 ORF2 gene which examined by RT-PCR. It indicated that the full-length cDNA clone of PRRSV attenuated strain TJM-F92 and recombinant PRRSV rTJM/Cap expressing PCV2 Cap protein were successfully constructed. It made an important foundation for studying on the pathogenic mechanisms of PRRSV and PRRSV-PCV2 vaccine in the future.
Animals ; Capsid Proteins ; genetics ; immunology ; Cell Line ; Circoviridae Infections ; veterinary ; virology ; Circovirus ; classification ; genetics ; metabolism ; Gene Expression ; Open Reading Frames ; Porcine Reproductive and Respiratory Syndrome ; virology ; Porcine respiratory and reproductive syndrome virus ; genetics ; metabolism ; Recombination, Genetic ; Swine ; Swine Diseases ; virology ; Viral Vaccines ; genetics ; immunology

Enterovirus 71 (EV71) is the main causative agent of hand, foot, and mouth disease (HFMD). This article presented the inhibitory activity of pentapeptides on the EV71 infection in rhabdomyosarcoma (RD) and suckling mice. The EV71 VP1 capsid protein expression levels and mRNA levels were analyzed by Western blotting and real-time PCR. The antiviral activity of pentapeptides in vivo was evaluated by weight changes and EV71 VP1 protein expression levels in intestines of suckling mice. Results revealed that the pentapeptide P010157 was able to inhibit EV71 replication in RD cells. After being incubated with the P010157 at a concentration of 100 microg x mL(-1) for 48 h, the level of EV71 vp1 mRNA in RD cells decreased by (92.0 +/- 6.3)%. The estimated EC50 was 2.2 microg x mL(-1). P010157 was able to inhibit EV 71-induced cytopathic effect (CPE) in RD cells. The cytotoxic activity of the compound was evaluated against RD cells by MTS assay. The results showed that P010157 had no obvious toxicity. In addition, the treated mice with P010157 did not exhibit weight loss, as was observed in untreated mice. EV71 replication reduced significantly as revealed by Western blotting. These findings suggest that P010157 could prevent EV71 proliferation in vitro and in vivo. P010157 is a novel compound for antiviral therapies against EV71, which merited further investigation.
Animals ; Antiviral Agents ; pharmacology ; Capsid Proteins ; genetics ; metabolism ; Enterovirus A, Human ; physiology ; Enterovirus Infections ; metabolism ; Humans ; Mice ; Oligopeptides ; pharmacology ; RNA, Messenger ; metabolism ; Rhabdomyosarcoma ; metabolism ; pathology ; virology ; Tumor Cells, Cultured ; Virus Replication ; drug effects

Antibodies, Monoclonal ; chemistry ; immunology ; Antigens, Viral ; chemistry ; genetics ; immunology ; Binding Sites ; Capsid Proteins ; chemistry ; genetics ; immunology ; Epitopes ; chemistry ; genetics ; immunology ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Hepatitis E ; immunology ; prevention & control ; virology ; Hepatitis E virus ; chemistry ; immunology ; Humans ; Molecular Docking Simulation ; Mutagenesis, Site-Directed ; Peptide Mapping ; Protein Binding ; Recombinant Proteins ; chemistry ; genetics ; immunology ; Viral Hepatitis Vaccines ; administration & dosage ; biosynthesis