Animals ; Evolution, Molecular ; Glycoproteins ; chemistry ; genetics ; immunology ; metabolism ; Mutation ; Phylogeny ; Rabies virus ; genetics ; physiology ; Viral Proteins ; chemistry ; genetics ; immunology ; metabolism

Animals ; Humans ; Influenza A virus ; immunology ; Influenza Vaccines ; immunology ; Protein Engineering ; Viral Matrix Proteins ; chemistry ; genetics ; immunology ; metabolism

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 E is an acute hepatitis casused by hepatitis E virus (HEV) in developing countries, where it occurs as cases sporadic and in epidemics form. The causative agent, hepatitis E virus, is transmitted primarily by the fecal-oral route. HEV is icosahedron non-enveloped virus, and its genome is a single-stranded, positive-sense, 3'-polyadenylated RNA about 7.5 kb in length. It contains three open reading frames (ORFs). Of which ORF1 codes for a polyprotein of 1693 amino acids and contain domains homologous to a viral methyltransferase, a papainlike cysteine protease, an RNA helicasre, and an RNA-dependent RNA polymerase, besides the most hypervariable region of the HEV genome. And ORF3 codes for a 123-amino-acide-long polypeptide with unknown function. While the major viral capsid protein (pORF2, ORF2 codes) of 660 amino acid was showed to contain the protective epitope. The bacterially expressed polypeptide disignated as NE2 has been proved to be a protective antige. And the anti-NE2 monoclonal antibodies (mAb) was screend, two of these mAbs 8C11 and 8H3 were showed to be against separate conformational neutralization epitope of hepatitis E virus (HEV). And these two mAb were used to screen for binding peptides from a 7-peptides phage display library. After four rounds of panning, tweenty-one positive monoclonal phages (11 for 8C11, and 10 for 8H3) were selected and the inserted fragments were sequenced. The DNA sequence coding for the obtained dominant peptide 8C11 (N'-His-Pro-Thr-Leu-Leu-Arg-Ile-C', named 8C11A) and 8H3 (N'-Ser-Ile-Leu-Pro-Tyr-Pro-Tyr-C', named 8H3A) were then synthesized and cloned to insert between amino acid 78 to 83 of hepatitis B core antigen (HBcAg), then expressed in E. coli. The recombinant proteins aggregate into homodimer or polymer on SDS-PAGE, and could bind with mAb 8C11 and 8H3 in Western blotting. Respectively, the recombinant protein C8C11A showed to be dimer mainly, which can bind with mAb 8C11. The monomer and dimer of C8H3A are in the same amount on SDS-PAGE, but only the dimer could bind with mAb 8H3 on Western blotting. The renatured recombinant proteins were all showed to aggregate into virus like particles which were similar as HBcAg on transmission electron micrograph. The dominant peptide 8H3A (N'-Ser-Ile-Leu-Pro-Tyr-ProTyr-C') that selected out by mAb 8H3 was further chemo-synthesized, and its binding activity was confirmed by BIAcore biosensor. The result showed that this 7-peptide can bind with mAb 8H3 in a big Ka and Kd form, which means the binding is not stable. These results implicated that conformational dependent neutralization epitope could be partially modeled by short peptide, which provided a feasible route for subunit vaccine development.
Amino Acid Sequence ; Animals ; Antibodies, Monoclonal ; immunology ; Blotting, Western ; Electrophoresis, Polyacrylamide Gel ; Epitopes ; chemistry ; genetics ; immunology ; metabolism ; Hepatitis B Core Antigens ; genetics ; metabolism ; Hepatitis E virus ; genetics ; immunology ; metabolism ; Mice ; Microscopy, Electron ; Molecular Sequence Data ; Peptide Library ; Peptides ; chemistry ; genetics ; immunology ; metabolism ; Recombinant Proteins ; genetics ; immunology ; metabolism ; ultrastructure ; Sequence Homology, Amino Acid ; Viral Proteins ; chemistry ; genetics ; immunology ; metabolism ; ultrastructure

In this study, Recombinant baculoviruses rBac-NF and rBac-NG were generated for expressing F and G proteins Nipah virus (NiV) . The expression of recommbinant G (rNG) and F (rNF) protein in rBac-NF and rBac-NG infected cells were confirmed by western-blot. Both rNG and rNF showed sensitive and specific antigenic reaction to rabbit serum anti-Nipah virus in indirect immunofluorescence detection and indirect ELISA. Immunization with rBac-NF and rBac-NG infected insect cells elicited G ad F protein specific antibody responses in mice. Furthermore, the G ad F specific antibodies could neutralize the infectivity of the VSVdeltaG* F/G, the NiV F and G envelope glycoproteins psudotyped recombinant Vesicular Stomatitis Virus expressing green fluorescence protein. The results demonstrated F and G protein expressed by the recombinant baculoviruses could be safe economic diagnostic antigens for the surveillance and monitoring of NiV and promising subunit vaccines for the prevention of NiV.
Animals ; Antigens, Viral ; immunology ; Baculoviridae ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; Nipah Virus ; chemistry ; genetics ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Recombination, Genetic ; Viral Envelope Proteins ; biosynthesis ; genetics ; immunology

OBJECTIVETo construct sub-unit vaccines of dengue virus type 1 to 4 and to analyze its immunogenicity.

METHODSEnvelope domain III s of dengue serotypes 1 and 2, as well as 3 and 4, were spliced by a linker (Gly-Gly-Ser-Gly-Ser)3 and cloned into vector pET-30a, then transformed into E. coli to express recombinant fusion proteins. The recombinant proteins were purified by high-performance liquid chromatography and mixed to immunize BALB/c mice. The neutralizing antibodies were tested by neutralizing assay, as well as in newborn mice challenged intracranially with dengue virus type 1 to 4.

RESULTSMice immunized with proteins could produce neutralizing antibodies, with titers of 1:34. 9, 1: 45.3, 1: 24.7 and 1:38.4 for DEN-1 to 4 respectively. 100% newborn mice challenged with DEN-1 or 2 in combination with sera from mice immunized with recombinant proteins were protected, whereas 83% protection was obtained when challenged with DEN-3 or 4.

CONCLUSIONThe recombinant proteins possess excellent immunogenicity to induce neutralizing antibodies and would be valuable for development of a tetravalent sub-unit vaccine.

Animals ; Antibodies, Neutralizing ; immunology ; Dengue Vaccines ; chemistry ; genetics ; immunology ; Dengue Virus ; genetics ; immunology ; Escherichia coli ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; Neutralization Tests ; Recombinant Fusion Proteins ; genetics ; immunology ; Viral Envelope Proteins ; genetics ; immunology

The purpose of this study is to elucidate the molecular mechanism of one-way serological reaction between XJ-160 virus and SINV by recombinant viruses which exchanged the glycoprotein genes individually or simultaneously. Three recombinant viruses were obtained based on the whole-length infectious cDNA clone of XJ-160 virus. The infectivity and pathogenesis to BHK-21 cells and animals were studied and the gene which controlled this one-way serological reaction phenomenon was searched by MCPENT. The results showed that the E2 glycoprotein was the main factor which influenced the growth rate, plaque morphology and pathogenicity of BHK-21 cells and suckling mice. The results of MCPENT showed that the E2 glycoprotein of SINV played a major role in this one-way serological reaction phenomenon. Our study identified the SINE2 gene was the determined gene for one way serological reaction between XJ-160 virus and SINV, and this research laid the foundation for further analysis of the genomic structure and function of SINV.
Alphavirus ; genetics ; immunology ; physiology ; Amino Acid Sequence ; Animals ; Cell Line ; DNA, Recombinant ; genetics ; Female ; Genetic Engineering ; Glycoproteins ; chemistry ; metabolism ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; Neutralization Tests ; Sindbis Virus ; immunology ; Viral Load ; Viral Proteins ; chemistry ; metabolism

A novel human ScFv H12 against SARS-CoV has been selected from a SARS immune library. In order to produce a large amount of ScFv H12, pET28a-H12 expression vector was constructed and ScFv H12 was expressed at yield about 30% of total proteins in E. coli . Here two different refolding procedures were used to refold ScFv H12 from inclusion body: gel filtration chromatography and dilution. The results showed that ScFv H12 could be efficiently refolded by both procedures. However, the refolding via gel filtration was 1.5 time more effective than that of dilution. The affinity of ScFv H12 to SARS-CoV virion was detected as Kd = 73.5 nmol/mL.
Antibodies, Monoclonal ; biosynthesis ; genetics ; Antibodies, Viral ; immunology ; Escherichia coli ; genetics ; metabolism ; Humans ; Immunoglobulin Fragments ; biosynthesis ; genetics ; immunology ; Immunoglobulin Variable Region ; biosynthesis ; genetics ; immunology ; Inclusion Bodies ; genetics ; immunology ; Protein Renaturation ; Recombinant Proteins ; biosynthesis ; chemistry ; immunology ; SARS Virus ; immunology

X5 protein is one of the putative unknown proteins of SARS-CoV. The recombinant protein has been successfully expressed in E. coli in the form of insoluble inclusion body. The inclusion body was dissolved in high concentration of urea. Affinity Chromatography was preformed to purify the denatured protein, and then the product was refolded in a series of gradient solutions of urea. The purified protein was obtained with the purity of > 95% and the yield of 93.3 mg x L(-1). Polyclonal antibody of this protein was obtained, and Western blotting assay indicated that the X5 protein has the strong property of antigen. Sixty-eight percent of the recombinant protein sequence was confirmed by LC-ESI-MS/MS analysis.
Amino Acid Sequence ; Animals ; Antibodies ; isolation & purification ; Escherichia coli ; genetics ; metabolism ; Gene Expression Regulation, Viral ; Inclusion Bodies ; chemistry ; metabolism ; Molecular Sequence Data ; Rabbits ; Recombinant Proteins ; genetics ; immunology ; isolation & purification ; SARS Virus ; genetics ; Viral Proteins ; genetics ; immunology ; isolation & purification

OBJECTIVETo observe the ability of dengue virus recombinant envelope protein domain expressed in E. coli to inhibit virus infection and induce the neutralizing antibody.

METHODSE III protein of Dengue virus serotypes 1-4 were expressed in E. coli BL21(DE3) then purified. Recombinant proteins were tested to inhibit DV2 from infecting BHK-21 cell. Rabbits were immunized with recombinant proteins to produce anti-E III serum. Antibody titers were determined by neutralizing assay.

RESULTSThe recombinant E III proteins of Dengue virus serotypes 1-4 were expressed in E. coli. They effectively protected BHK cells in culture against DV2 infection. All four type anti-E III sera can neutralize DV2 but their efficacies are different.

CONCLUSIONproteins of dengue virus expressed in E. coli can directly inhibit DV2 infection. Neutralizing antibodies were induced by E III proteins. Both E III protein of dengue virus and the neutralizing antibodies they induced are more efficient in inhibiting homologous dengue serotypes infection than heterologous serotypes.

Animals ; Antibodies, Viral ; immunology ; Cell Line ; Cricetinae ; Dengue ; immunology ; prevention & control ; virology ; Dengue Virus ; chemistry ; genetics ; immunology ; physiology ; Down-Regulation ; Escherichia coli ; genetics ; metabolism ; Humans ; Immunization ; Mesocricetus ; Protein Structure, Tertiary ; Rabbits ; Recombinant Proteins ; chemistry ; genetics ; immunology ; Viral Envelope Proteins ; chemistry ; genetics ; immunology ; Virus Replication