Cloning and Sequence Analysis of HN and F Protein Genes from a Strain of Goose Paramyxovirus

[ Objective] The study was to clone HN and F genes from GX1 strain of goose paramyxovirus and analyze their sequences. [ Method] According to the full nucleotide sequence of GPV-SF02 strain of goose paramyxovirus, two pairs of pdmers were designed to amplify the HN and F genes from GX1 strain of goose paramyxovirus isolated from diseased goose in Guangxi Zhuang Autonomous Region; the amplified products were ligated into pMD18-T vector and sequenced. [ Result ] HN and F genes of this strain tested were 1 716 and 1 662 bp in full nucleotide length, respectively; both showed the homologues of about 97.3% with GPV- SF02 strain, of 80.3% -97.5% with strains LaSota, F48E9 and JS, of just 84.8% with Miyadera strain. [ Conclusion] The results show that isolated strain BX1 matches to virulent APMV-1 strain, belonging to genotype Ⅶ of APMV-1 strain.

Anti-tumor Immune Response Mediated by Newcastle Disease Virus HN Gene

Hemagglutinin-neuramidinase（HN） is one of the most important surface structure proteins of the Newcastle disease virus（NDV）. HN not only mediates receptor recognition but also possesses neuraminidase（NA） activity, which gives it the ability to cleave a component of those receptors, NAcneu. Previous studies have demonstrated that HN has interesting anti-neoplastic and immune-stimulating properties in mammalian species, including humans. To explore the application of the HN gene in cancer gene therapy, we constructed a Lewis lung carcinoma（LLC） solid tumor model using C57BL/6 mice. Mice were injected intratumorally with the recombinant adenovirus expressing HN gene（Ad-HN）, and the effect of HN was explored by natural killer cell activity assay, cytotoxic lymphocyte activity assay, T cell subtype evaluation, and Th1/Th2 cytokines analysis. The results demonstrate that HN not only can elicit clonal expansion of both CD4＋ and CD8＋ T cell populations and cytotoxic T lymphocyte（CTL） and killer cell response, but also skews the immune response toward Th1. Thus, vaccination with Ad-HN may be a potential strategy for cancer gene therapy.

Phylogenetic Analysis of HN Gene of Eight Pigeon NDV Isolates in Guangxi

[Objective] The paper was to provide a basis for scientific prevention and control of pigeon Newcastle disease（ND）.[Method] The HN gene of eight pigeon NDV strains isolated from different pigeon farms in Guangxi were amplified by RT-PCR,sequenced and analyzed.The molecular evolution characteristics of HN gene of pigeon NDV isolates in Guangxi was discussed.[Result] The nucleotide sequence length of HN gene of the eight NDV isolates was 1 716 bp,encoding 571 amino acids.They belonged to virulent group C,and the gene length characteristic of HN gene accorded with virulent strain.Analysis of nucleotide homologies indicated that the eight NDV isolates shared higher homology with genotype VIb,ranging from 90.4% to 99.5%.Phylogenetic tree analysis demonstrated that the genetic relationship between the eight NDV strains in Gangxi and the NDV isolates from Guangxi,Guangdong,Jilin,Liaoning,Yunnan and Heilongjiang during 2011 and 2013 was close.They were located in the same cladogram branch.[Conclusion] We assume that the eight pigeon NDV isolates in Guangxi all belong to the gene class II genotype VI b NDV.

Epitope variation in the Newcastle disease virus HN gene under antibody immune selective pressure in cell culture

The influence of antibody immune selective pressure on Newcastle disease virus (NDV) HN and F gene mutations was studied in cell cultures.NDV field strain TZ060107 was inoculated into chicken embryo fibroblast cells and continuously passaged with (group A) or without (group B) anti-NDV monospecific serum.Each group contained three independent passage series.HN and F genes were amplified and sequenced for the 10th,20th,30th,40th and 50th generations of each serial passage,and compared with the original strain.The results demonstrated that increased HN gene mutations were observed in group A with the antibody than in group B without the antibody.The nonsynonymous (NS) to synonymous (S) mutations ratio was 6 for group A,significantly higher than 3.4 in group B.In group A with the antibody,there were five stable NS mutations in HN gene,three of which (related to aa#353,521 and 568) were related to known epitopes.There were two stable NS mutations in F gene in group A,but no stable NS mutations in group B.The NS/S ratios of F gene were less than 2.5 for both groups A and B.Our results suggested that the antibody strongly influenced HN gene mutations,while the F gene was less influenced by the same antibody.