We produced high pathogenic avian influenza H5N1 haemagglutinin protein HA1 in recombinant Pichia pastoris in a 10 L fermentor, to establish a high-density cell fermentation method. We studied the effects of different factors such as culture temperature, induced temperature, methanol feeding methods, trace elements on the growth of Pichia pastoris, the yield and the biologic activity of recombinant HA1 protein. The culture temperature in pre-induced and induced stage were optimized at 25 degrees C to adapt cell growth and recombinant protein expression, and induced temperature at 25 degrees C also resulted in higher biologic activity of rHA1 than at 30 degrees C. The binding activity of rHA1 against a wide-spectrum neutralizing antibody was susceptible to the presence of any trace elements, although trace elements would essentially benefit for the cell fermentation. As a conclusion, the expression level of rHA1 produced with optimized fermentation process reached 120 mg/L, which was 10.5 times higher than the one produced in regular shaking flask. The resultant high-density cell fermentation can likely produce rHA1 of H5N1 in large scale.
Fermentation ; Hemagglutinins, Viral ; biosynthesis ; genetics ; Influenza A Virus, H5N1 Subtype ; genetics ; metabolism ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis

Influenza vaccine strains have been traditionally developed by annual reassortment between vaccine donor strain and the epidemic virulent strains. The classical method requires screening and genotyping of the vaccine strain among various reassortant viruses, which are usually laborious and time-consuming. Here we developed an efficient reverse genetic system to generate the 6:2 reassortant vaccine virus from cDNAs derived from the influenza RNAs. Thus, cDNAs of the two RNAs coding for surface antigens, haemagglutinin and neuraminidase from the epidemic virus and the 6 internal genes from the donor strain were transfected into cells and the infectious viruses of 6:2 defined RNA ratio were rescued. X-31 virus (a high-growth virus in embryonated eggs) and its cold-adapted strain X-31 ca were judiciously chosen as donor strains for the generation of inactivated vaccine and live-attenuated vaccine, respectively. The growth properties of these recombinant viruses in embryonated chicken eggs and MDCK cell were indistinguishable as compared to those generated by classical reassortment process. Based on the reverse genetic system, we generated 6 + 2 reassortant avian influenza vaccine strains corresponding to the A/Chicken/Korea/MS96 (H9N2) and A/Indonesia/5/2005 (H5N1). The results would serve as technical platform for the generation of both injectable inactivated vaccine and the nasal spray live attenuated vaccine for the prevention of influenza epidemics and pandemics.
Animals ; Chick Embryo ; Chickens ; Genetic Engineering ; Hemagglutinins, Viral/genetics/metabolism ; Humans ; Influenza A Virus, H5N1 Subtype/*genetics/immunology ; Influenza A Virus, H9N2 Subtype/*genetics/immunology ; Influenza Vaccines/*genetics/metabolism ; Influenza in Birds/immunology/virology ; Influenza, Human/immunology/*prevention & control/virology ; Neuraminidase/genetics/metabolism ; Transgenes ; Vaccines, Attenuated/*genetics/metabolism ; Viral Proteins/genetics/metabolism

Several antigen epitopes were designed according to the sequences of Swine influenza virus hemagglutinin (HA) genes and lined with the interval. The gene was amplified by PCR and sub cloned into pET30a (+) vector. The fusion protein was expressed in E. coli BL21 (DE3) by induced with IPTG and purified by affinity chromatography. The molecular weight of the protein was about 20 kD in SDS-PAGE. Immunological activity of the fusion protein was analyzed by Western blot. The results showed that the fusion protein could interact with anti-His antibody and the rabbit antiserum against SIV. The immunized mouse can produced antibodies against the target peptide and HI antibody against SIV H1N1 or H3N2. This study provides a new vaccine candidate for SIV.
Amino Acid Sequence ; Animals ; Antibodies, Viral ; blood ; Antigens, Viral ; biosynthesis ; genetics ; immunology ; Base Sequence ; Epitopes ; genetics ; immunology ; metabolism ; Escherichia coli ; genetics ; metabolism ; Hemagglutinins ; genetics ; immunology ; Humans ; Immunization ; Influenza A Virus, H1N1 Subtype ; genetics ; immunology ; Influenza A Virus, H3N2 Subtype ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; Random Allocation ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology

To construct Fv antibodies against H5N1 Avian influenza virus hemagglutinin,extracted mRNA from B lymphoblastoid cell lines secreting anti-HA antibodies was used and the VH and VL genes were amplified by RT-PCR and linked together by splicing overlap extension (SOE) with (Gly4 Ser)3 linker. The recombinant plasmid was then transformed to E. coli BL21(DE3) and sequence analysis indicated the total length of scFv was 714 bp and the expression of Fv was validated by PAGE and Western blot.
Animals ; Antibodies ; genetics ; metabolism ; pharmacology ; Birds ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Gene Expression Regulation ; Hemagglutinins ; immunology ; Immunoglobulin Heavy Chains ; genetics ; Immunoglobulin Light Chains ; genetics ; Immunoglobulin Variable Region ; genetics ; metabolism ; Influenza A Virus, H5N1 Subtype ; drug effects ; immunology ; Influenza in Birds ; virology ; Mice ; Mice, Inbred BALB C ; Recombinant Fusion Proteins ; genetics ; metabolism ; pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; Viral Proteins ; immunology

The purpose of the study is to construct recombinant goat pox virus (GPV) expressing Peste des petits ruminants virus (PPRV) H protein, and to evaluate the immunization effect. Recombinant GPV containing PPRV H gene (rGPV-PPRV-H) was selected and purified by gpt and eGFP utilizing plaque purification, and the final selected recombinant GPV was proved to be purified by PCR. Immunofluorescence and Western blotting showed that the recombinant virus could express H protein of PPRV while infecting lamb testis cells. Six goats were immunized with 2 x 10(6) PFU rGPV-PPRV-H through intradermal injection, and were immunized for the second time at 28 days with the same dose recombinant virus after first immunization. Serum was collected after immunization, and was analyzed for the neutralization antibodies. 21 days after first immunization, the neutralization antibodies of GPV were 40, 80, > or = 80, > or = 80, 40, > or = 80 in turn, and neutralization antibodies of PPRV were 80, 80, 80, 80, 40, 40, 10 in turn; 14 days after second immunization, the neutralization antibodies of GPV were all > or = 80, and the neutralization antibodies of PPRV were > 80, 80, > 80, 80, 80 and 40 in turn. This study established a foundation for the industrialization of the PPRV recombinant GPV vaccine.
Animals ; Capripoxvirus ; genetics ; immunology ; Goat Diseases ; immunology ; prevention & control ; virology ; Goats ; Hemagglutinins, Viral ; genetics ; immunology ; metabolism ; Peste-des-Petits-Ruminants ; immunology ; prevention & control ; Peste-des-petits-ruminants virus ; genetics ; immunology ; Recombinant Proteins ; genetics ; immunology ; metabolism ; Vaccines, Combined ; immunology ; Vaccines, Synthetic ; immunology ; Viral Vaccines ; immunology