To investigate the mechanism of the major capsid protein VP5 (encoded by the UL19 gene) of oncolytic herpes simplex virus type Ⅱ (oHSV2) in regulating the antitumor function of immune cells, we constructed a mouse breast cancer cell line 4T1-iRFP-VP5-GFP stably expressing VP5 protein, near-infrared fluorescent protein (iRFP), and green fluorescent protein (GFP) by using the PiggyBac transposon system. Flow cytometry and Western blotting were employed to screen the monoclonal cell lines expressing both GFP and VP5 and examine the expression stability of UL19 in the constructed cell line. The results of SYBR Green I real-time PCR and Western blotting showed that the copies of UL19 and the expression level of VP5 protein in the 15th passage of 4T1-iRFP-VP5-GFP cells were significantly higher than those in the 4T1 cells transiently transfected with UL19, demonstrating the stable insertion of UL19 into the 4T1 cell genome. The real-time cell analysis (RTCA) was employed to monitor the proliferation of 4T1-iRFP-VP5-GFP cells, which showed similar proliferation activity to their parental 4T1 cells. Further studies confirmed that NK92 cells exhibited stronger cytotoxicity against 4T1-iRFP-VP5-GFP cells than against 4T1 cells. This study layed a foundation for elucidating the role of VP5 protein in regulating immune cells, including T cells and NK cells, via HLA-E in 4T1 cells to exert the anti-tumor function.
Animals ; Mice ; DNA Transposable Elements/genetics* ; Cell Line, Tumor ; Capsid Proteins/biosynthesis* ; Transfection ; Green Fluorescent Proteins/metabolism* ; Oncolytic Viruses/genetics* ; Female ; Simplexvirus/genetics*

HPV16 L2E7 is a fusion protein used for therapeutical vaccine targeting HPV virus. To increase its expression in Escherichia coli, we optimized the codon usage of HPV16 l2e7 gene based on its codon usage bias. The optimized gene of HPV16 sl2e7 was cloned into three different vectors: pGEX-5X-1, pQE30, ET41a, and expressed in JM109, JM109 (DE3) and BL21 (DE3) lines separately. A high expression line was selected with pET41a vector in BL21 (DE3) cells. After optimization of the growth condition, including inoculation amount, IPTG concentration, induction time and temperature, the expression level of HPV16 L2E7 was increased from less than 10% to about 28% of total protein. HPV16 L2E7 protein was then purified from 15 L culture by means of SP Sepharose Fast Flow, Q Sepharose Fast Flow and Superdex 200 pg. After renaturing, HPV16 L2E7 protein with ≥ 95% purity was achieved, which was confirmed via SDS-PAGE gel and Western blotting. The combined use of purified HPV16 L2E7 and CpG helper has shown clear inhibition of tumor growth in mice injected with tumor cells, with six out of eight mice shown no sign of tumor. This study lays a solid foundation for a new pipeline of large-scale vaccine production.
Animals ; Capsid Proteins ; biosynthesis ; Codon ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; Genetic Vectors ; Human papillomavirus 16 ; Mice ; Neoplasms, Experimental ; prevention & control ; Oncogene Proteins, Viral ; biosynthesis ; Papillomavirus E7 Proteins ; biosynthesis ; Papillomavirus Vaccines ; therapeutic use ; Recombinant Fusion Proteins ; biosynthesis

A truncated mutant of the Open Reading Frame 2 (ORF2, aa384-606) was amplified from cDNA of genotype IV hepatitis E virus (HEV) by polymerase chain reaction (PCR), subcloned to expression plasmid pTO-T7, and expressed in Escherichia coli. SDS-PAGE and Western blotting were used to detect and identify the recombinant protein, namely rP24. After washing of inclusion bodies, dissolving in denaturing agents, refoldeding by dialysis, ion exchange chromatography and gel chromatography, dynamic light scatter was used to study the hydrated radius of rP24. Western blotting was applied to detect the immunoreactivity of rP24, and mouse immunity test and indirect enzyme linked immunosorbent assay (ELISA) were applied to evaluate the immunogenicity and the detection rate of HEV positive and negative serum. SDS-PAGE and Western blotting show that rP24 was highly expressed in the form of inclusion bodies after induction, and had strong immunoreactivity to monoclonal antibody (McAb) 15B2. After a multi-step purification of rP24, Western blotting indicated that the purified rP24 also had strong immunoreactivity to neutralizing McAb 8C11 and HEV positive serum, suggesting that rP24 simulated the nature structure of HEV capsid protein. Dynamic light scatter demonstrated that the average hydration radius of purified rP24 was 7.48 nm. The mouse immunity test showed that the purified rP24 also had good immunogenicity, and the period of serum antibodies converted from negative to positive was very short, but the antibodies maintained more than 20 weeks. Indirect ELISA tests showed that the detection rate of was the same as anti-HEV-IgG diagnostic kit (Wan Tai corporation). Taken together, the rP24 simulated the neutralizing epitopes of natural HEV, and had strong immunoreactivity and immunogenicity. It provided a basis for the further investigation of the difference of infection mechanism between genotype I and genotype IV HEV.
Animals ; Antibodies, Monoclonal ; Antibodies, Neutralizing ; Blotting, Western ; Capsid Proteins ; biosynthesis ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Epitopes ; Genotype ; Hepatitis E virus ; Mice ; Mutant Proteins ; biosynthesis ; Open Reading Frames ; Recombinant Proteins ; biosynthesis

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

Hepatitis B virus (HBV) DNA replication takes place in the viral capsid that consists of 180 or 240 copies of HBV capsid (HBc or core) protein. The monomeric core protein contains an apical loop region that forms the spikes on the surface of viral capsid upon core dimerization and capsid assembly. To investigate the impact on HBV DNA replication through gene engineering at the spike of HBV capsid. plasmids expressing engineered HBc with linker-fused enhanced green fluorescent protein (EGFP) or shortened EGFP insertion at the spike region were constructed by Restriction Digestion and Ligation-independent Cloning (RLIC). The wildtype or mutant HBc construct was cotransfected with HBV1.1c(-), a plasmid containing 1.1 unit-length HBV genome with deficiency in HBc expression, into HEK293 cells, respectively. GFP signal was observed through a fluorescence microscope and HBV DNA replicative intermediates were assayed by Southern blotting to determine the expression and functions of different recombinants. Our results demonstrated that the RLIC method was effective to generate deletion or insertion in the apical loop region of HBc. Both HBc-EGFP recombinants with different linkers produced green fluorescence but with different subcellular distribution pattern. However, HBV DNA replication was not detected with the trans-complementation of these two HBc recombinants. In addition, other recombinants including the one only with the deletion of aa79-80 failed to support HBV replication. Taken together, our results suggest that RLIC is a robust method which can be broadly applied in gene engineering; different peptide linkers may have different influences on the functions of an engineered fusion protein; and HBc aa79-80 play a critical role for HBc to support HBV DNA replication.
Capsid Proteins ; genetics ; Cloning, Molecular ; Genetic Engineering ; methods ; Green Fluorescent Proteins ; biosynthesis ; genetics ; HEK293 Cells ; Hepatitis B Core Antigens ; biosynthesis ; genetics ; Hepatitis B virus ; genetics ; physiology ; Humans ; Mutation ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Transfection ; Virus Replication

To construct a recombinant replication-defective human adenovirus type 5 expressing Cap protein of PCV2 and test the immunological efficacy in mice. In this study, the recombinant replication-defective human adenovirus type 5, named as rAd5-Cap (wt-rAd5), was constructed through homologous recombination internally in the HEK293AD cells after co-transfection of the Pac I-linearized backbone plasmid and the shuttle plasmid pacAd5CMV-Cap containing the open reading frame (ORF2) of the porcine circovirus type 2 (PCV2) cap protein or pacAd5CMV without inserted fragment. Furthermore, the rAd5-Cap could induce the expression of PCV2 cap protein in the HEK293AD cells with high efficacy evaluated by the RT-PCR and indirect immunofluorescence assay (IFA). The virus titer of rAd5-Cap could reach up to 10(8.5) TCID50/mL similarly to that of wt-rAd5, indicating that there was little affect on the virus proliferation after the insertion of PCV2 cap protein gene. The humeral immune responses could be activated and detected 14 days after the inoculation of the mice with 10(7) TCID50 rAd5-Cap intramuscularly, and constantly in crease in another 14 days. These molecular biological and animal experiments results demonstrated that the PCV2 cap protein could be efficiently expressed by the recombinant adenovirus rAd5-Cap in eukaryotic cells and induce robust immune responses in mice, which laid a good foundation for the development of new type vaccine against porcine circovirus.
Adenoviruses, Human ; genetics ; Animals ; Antibodies, Viral ; blood ; Capsid Proteins ; genetics ; immunology ; Circovirus ; immunology ; Defective Viruses ; genetics ; HEK293 Cells ; Humans ; Mice ; Recombinant Proteins ; biosynthesis ; immunology ; Virus Replication

To observe how anti-group A rotavirus antibody seropositivity rates and levels have changed in the western region of Gyeongnam Province, 2,030 serum samples collected at four collection periods (1989-1990, 1994-1995, 1999-2000, and 2004-2005) were tested by Enzyme-Linked Immunosorbent Assay for IgG, and IgA antibodies reacting to recombinant VP6 protein. The seroprevalences exhibit no regular patterns over a 16-yr period. For all four collection periods, the anti-rVP6 IgG levels rose steadily during the first 5 months of life, after which they remained high. However, the 2-9 yr and 10-39 yr groups had significantly higher IgG levels in 1999-2000 and 2004-2005, respectively, than in the other collection periods. The 1-5 mo, 40- > or = 60 yr, and 4-29 yr groups had significantly higher IgA levels in 1989-1990, 1999-2000, and 2004-2005, respectively. The 4 yr (25.0%), 5-9 yr (18.8%), 10-14 yr (41.1%), 20-29 yr (35.0%), and 30-39 yr (20.0%) groups in 2004-2005 had significant higher IgA seropositivity rate compared to the other three collection periods. These observations suggest that in the western region of Gyeongnam Province since the late 1990s, rotavirus reinfection has occurred more frequently than previously, with all ages being at risk.
Adult ; Aged ; Antibodies, Viral/*blood ; Antigens, Viral/genetics/immunology/metabolism ; Capsid Proteins/genetics/immunology/metabolism ; Child ; Child, Preschool ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin A/blood ; Immunoglobulin G/blood ; Infant ; Infant, Newborn ; Male ; Middle Aged ; Recombinant Proteins/biosynthesis/genetics/immunology ; Republic of Korea/epidemiology ; Rotavirus/isolation & purification/*metabolism ; Rotavirus Infections/*epidemiology/virology ; Seroepidemiologic Studies ; Time Factors ; Young Adult

To construct and express a composite gene vaccine for human papillomavirus 58(HPV58)-associated cervical cancer, we inserted HPV58mE6E7 fusion gene into pCI-Fc-GPI eukaryotic expression vector, constructing a recombinant plasmid named pCI-sig-HPV58mE6E7-Fc-GPI. Then we further inserted fragment of sig-HPV58mE6E7Fc-GPI into the novel vaccine vector PVAX1-IRES-GM/B7, constructing PVAX1-HPV58mE6E7FcGB composite gene vaccine. PVAX1-HPV58mE6E7FcGB vaccine was successfully constructed and identified by restriction endonuclease and sequencing analysis. Eukaryotic expression of fusion antigen sig-HPV58mE6E7-Fc-GPI and molecular ad-juvant GM-CSF and B7. 1 were proved to be realized at the same time by flow cytometry and immunofluorescence. So PVAX1-HPV58mE6E7FcGB can be taken as a candidate of therapeutic vaccine for HPV58-associated tumors and their precancerous transformations.
Cancer Vaccines ; biosynthesis ; genetics ; Capsid Proteins ; biosynthesis ; genetics ; Female ; Humans ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; Papillomavirus E7 Proteins ; biosynthesis ; genetics ; Papillomavirus Vaccines ; biosynthesis ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Uterine Cervical Neoplasms ; prevention & control ; Vaccines, DNA ; biosynthesis

Chicken anemia virus (CAV) is an important viral pathogen that causes anemia and severe immunodeficiency syndrome in chickens worldwide. In this study, a potential diagnostic monoclonal antibody against the CAV VP1 protein was developed which can precisely recognize the CAV antigen for diagnostic and virus recovery purposes. The VP1 gene of CAV encoding the N-terminus-deleted VP1 protein, VP1Nd129, was cloned into an Escherichia (E.) coli expression vector. After isopropyl-beta-D-thiogalactopyronoside induction, VP1Nd129 protein was shown to be successfully expressed in the E. coli. By performing an enzyme-linked immunoabsorbent assay using two coating antigens, purified VP1Nd129 and CAV-infected liver tissue lysate, E3 monoclonal antibody (mAb) was found to have higher reactivity against VP1 protein than the other positive clones according to the result of limiting dilution method from 64 clones. Using immunohistochemistry, the presence of the VP1-specific mAb, E3, was confirmed using CAV-infected liver and thymus tissues as positive-infected samples. Additionally, CAV particle purification was also performed using an immunoaffinity column containing E3 mAb. The monoclonal E3 mAb developed in this study will not only be very useful for detecting CAV infection and performing histopathology studies of infected chickens, but may also be used to purify CAV particles in the future.
Animals ; Antibodies, Monoclonal/biosynthesis/genetics/*immunology ; Antigens, Viral/analysis ; Capsid Proteins/genetics/*immunology ; Chicken anemia virus/genetics/*immunology ; *Chickens ; Circoviridae Infections/blood/immunology/*veterinary/virology ; Escherichia coli/genetics ; Immunohistochemistry/veterinary ; Liver/virology ; Mice ; Mice, Inbred BALB C ; Microscopy, Fluorescence/veterinary ; Poultry Diseases/blood/immunology/*virology ; Specific Pathogen-Free Organisms ; Thymus Gland/virology

In order to increase the expression level of target gene and to simplify the purifying process of separation and purification, we performed the transgenetic research of antigen VP7 gene into peanut via Agrobacterium tumefaciens. The plant binary expression vector is pBOG3VP7 harboring fusion gene oleosin-vp7, which is promoted by ole-promoter. Cotyledon nodes were used as transformation recipients. Transformed individuals were obtained through selection on medium containing 125 mg L-1 Kan. Integration of transgenes was assessed by PCR amplification and PCR-Southern blot hybridization. Taking pBOG3VP7 plasmid as positive control, non-transformed peanut as negative control. 6 plants among 11 plants grown up through seletion medium were detected by PCR and the rate of positive plants is 54.5%. PCR positive plants were further analysed by PCR-Southern blot hybridization. The results showed that 3 plants have DNA bloting bands. The results also showed that the foreign gene was integrated into genome of transformed peanuts. Elevated expression of rotavirus VP7 antigen in transgenic peanuts was a critical factor in the development of efficient and cheap plant oral vaccine.
Agrobacterium tumefaciens ; genetics ; Antigens, Viral ; biosynthesis ; genetics ; Arachis ; genetics ; metabolism ; Capsid Proteins ; biosynthesis ; genetics ; Plants, Genetically Modified ; genetics ; metabolism ; Rotavirus ; genetics ; immunology ; Transformation, Genetic ; Vaccines, Synthetic