Objective:To discuss the possibility of expressing the haemagglutinin-neuraminidase（HN） protein in prokaryotic system such as Escherichia coli（E.coli） cells by cloning the full length HN gene.Methods:The full leng...Objective:To discuss the possibility of expressing the haemagglutinin-neuraminidase（HN） protein in prokaryotic system such as Escherichia coli（E.coli） cells by cloning the full length HN gene.Methods:The full length HN gene of Newcastle Disease Virus（NDV） of size 1 734 bp was preciously isolated by RT-PCR.The sequence was assessed and submitted to Nucleic Acid Databank（NCBI） and the gene ID was EU215390.1 after cloning and sequencing.Now the assessed HN gene was subcloned into pET 32 a+ expression vector for production the HN protein in E.coli, BL21（DE3） P<sup>LYS</sup>S cells following standard protocols.The crude lysate protein from the induced positive clone was size assessed by sodium dodecyl sulfale-polyacrylamide gel electrophoresis （SDS-PAGE） and their haemagglutination（HA） property against chicken RBC was assessed by standard micro HA test.Results:The molecular size of the full HN gene of NDV as assessed by cloning and digesting the positive clone to release the insert was 1.7 kb.The expressed protein in both crude and pure form was assessed to be 63 kDa and 81 kDa,respectively.The HA activity of the crude protein of the positive clone was 1 in 40.Conclusions:This finding indicates that the fusion protein retains the biological activity of native protein in the crude form and therefore could be used as a diagnostic reagent for antibody detection and for routine assessment of immune status in commercial layer forms.展开更多
Positive selection and differential selective pressure analyses were carried out to study Haemagglutinin (HA) genes of H9N2 influenza viruses from different hosts in this paper. Results showed that, although most posi...Positive selection and differential selective pressure analyses were carried out to study Haemagglutinin (HA) genes of H9N2 influenza viruses from different hosts in this paper. Results showed that, although most positions in HAs were under neutral or purifying evolution, a few positions located in the antigenic regions and receptor binding sites were subject to positive selection and some of them were even positively selected at the population level. In addition, there were always some positions differentially selected for viruses from different hosts. Both selection pressure working on HA codons and positions differentially selected might account for the extension of the host range and adaptations to different hosts of H9N2 influenza viruses.展开更多
将分别来自禽流感病毒A/Goose/Guangdong/3/96(H5N1)毒株的HA基因和A/Goose/Guangdong/1/96(H5N1)NP基因重组到禽痘病毒基因组中,获得了能同时高效表达这两种蛋白的重组禽痘病毒(rFPV HA NP)。将rFPV HA NP经翅膀刺种途径接种8周龄SPF鸡...将分别来自禽流感病毒A/Goose/Guangdong/3/96(H5N1)毒株的HA基因和A/Goose/Guangdong/1/96(H5N1)NP基因重组到禽痘病毒基因组中,获得了能同时高效表达这两种蛋白的重组禽痘病毒(rFPV HA NP)。将rFPV HA NP经翅膀刺种途径接种8周龄SPF鸡,并设亲本禽痘病毒免疫和非免疫对照组。免疫后4周分别用10LD50的高致病力禽流感病毒(HPAIV)A/Goose/Guangdong/1/96(H5N1)和A/FPV/Rostock/34(H7N1)毒株进行攻击。结果重组禽痘病毒rFPV HA NP免疫鸡群后能够诱导产生高水平的特异性抗体,可完全抵抗H5N1毒株的致死性攻击,并可有效阻止H7N1病毒攻击后病毒在泄殖腔的排出。而禽痘病毒免疫组和非免疫对照组在攻毒后全部发病并死亡。结果表明NP在与HA共同表达时,在诱导交叉保护性方面有一定的免疫增强功能。展开更多
文摘Objective:To discuss the possibility of expressing the haemagglutinin-neuraminidase（HN） protein in prokaryotic system such as Escherichia coli（E.coli） cells by cloning the full length HN gene.Methods:The full length HN gene of Newcastle Disease Virus（NDV） of size 1 734 bp was preciously isolated by RT-PCR.The sequence was assessed and submitted to Nucleic Acid Databank（NCBI） and the gene ID was EU215390.1 after cloning and sequencing.Now the assessed HN gene was subcloned into pET 32 a+ expression vector for production the HN protein in E.coli, BL21（DE3） P<sup>LYS</sup>S cells following standard protocols.The crude lysate protein from the induced positive clone was size assessed by sodium dodecyl sulfale-polyacrylamide gel electrophoresis （SDS-PAGE） and their haemagglutination（HA） property against chicken RBC was assessed by standard micro HA test.Results:The molecular size of the full HN gene of NDV as assessed by cloning and digesting the positive clone to release the insert was 1.7 kb.The expressed protein in both crude and pure form was assessed to be 63 kDa and 81 kDa,respectively.The HA activity of the crude protein of the positive clone was 1 in 40.Conclusions:This finding indicates that the fusion protein retains the biological activity of native protein in the crude form and therefore could be used as a diagnostic reagent for antibody detection and for routine assessment of immune status in commercial layer forms.
文摘Positive selection and differential selective pressure analyses were carried out to study Haemagglutinin (HA) genes of H9N2 influenza viruses from different hosts in this paper. Results showed that, although most positions in HAs were under neutral or purifying evolution, a few positions located in the antigenic regions and receptor binding sites were subject to positive selection and some of them were even positively selected at the population level. In addition, there were always some positions differentially selected for viruses from different hosts. Both selection pressure working on HA codons and positions differentially selected might account for the extension of the host range and adaptations to different hosts of H9N2 influenza viruses.
文摘将分别来自禽流感病毒A/Goose/Guangdong/3/96(H5N1)毒株的HA基因和A/Goose/Guangdong/1/96(H5N1)NP基因重组到禽痘病毒基因组中,获得了能同时高效表达这两种蛋白的重组禽痘病毒(rFPV HA NP)。将rFPV HA NP经翅膀刺种途径接种8周龄SPF鸡,并设亲本禽痘病毒免疫和非免疫对照组。免疫后4周分别用10LD50的高致病力禽流感病毒(HPAIV)A/Goose/Guangdong/1/96(H5N1)和A/FPV/Rostock/34(H7N1)毒株进行攻击。结果重组禽痘病毒rFPV HA NP免疫鸡群后能够诱导产生高水平的特异性抗体,可完全抵抗H5N1毒株的致死性攻击,并可有效阻止H7N1病毒攻击后病毒在泄殖腔的排出。而禽痘病毒免疫组和非免疫对照组在攻毒后全部发病并死亡。结果表明NP在与HA共同表达时,在诱导交叉保护性方面有一定的免疫增强功能。
