Genome sequencing and analysis of foot-and-mouth disease virus Asia1/YNBS/58 strain / 病毒学报

The full-length genomic sequence of foot-and-mouth disease virus (FMDV) Asia1/YNBS/58 strain was determined by RT-PCR and compared with other 17 reference strains. The results showed that the complete genome of Asia1/YNBS/58 was 8164nt long including a 1061-nt 5' untranslated region (UTR), a 6990-nt open reading frame (ORF), and a 113-nt 3'UTR. The homology analysis indicated that the UTR regions and non-structural proteins were more conserved than the structural proteins in FMDV. VP1 exhibited the lowest conservation and VP4 was exceptionally conserved. The VP1-, VP2-, and VP3-based phylogenetic trees were divided into distinct clusters according to different serotypes, while the other gene-based phylogenetic trees exhibited some degree of intercross among serotypes. This study is the first description of the full-length genomic sequence of FMDV Chinese serotype Asia1.

Establishment of indirect ELISA diagnose based on the VP1 structural protein of foot-and-mouth disease virus (FMDV) in pigs / 生物工程学报

The complete gene encoding the structural protein of FMDV(VP1) was subcloned into expression vector pPROex-HT, resulting in the fusion expression plasmid pPROexHT-VP1. After transformed into E. coli BL21(DE3) and induced by IPTG, the fusion protein was expressed in high level. Western blot was performed to confirm that the expressed fusion protein could specifically react with antiserum against FMDV. Based on the fusion protein further purified, a novel indirect ELISA (VP1-ELISA) was developed to detect FMDV antibody in pigs. Comparison between VPl-ELISA and the government standard kit (liquid phase block ELISA) showed the two methods had 96.25 percent agreement by detecting 80 serum samples, indicating that the indirect VP1-ELISA was specific and sensitive.

Molecular cloning and characteristics of cDNA encoding pig beta6 subunit for FMDV receptor / 生物工程学报

In order to study the roles of integrin beta6 in Foot-and-Mouth Disease Virus infection, pig integrin beta6 was firstly molecularly cloned from RNA of the tongue and lung of recovered pig infected experimentally with foot-and-mouth-disease virus (FMDV), and was compared with the beta6 gene of other animals available in GenBank at nucleotide and amino acid leves. GeneBank association number of the beta6 gene is EF432729. Pig integrin beta6 gene (2367bp) encodes a polypeptide of 788 amino acids consisting of 9 potential N-linked glycosylation sites, 3 Glycosaminoglycan attachment sites, a cGMP-dependent protein kinase phosphorylation site, 10 Protein kinase C phosphorylation sites, 2 EGF-like domains and 2 cysteine-rich regions. Pig integrin beta6 subunit has a 26-residue putative signal peptide, a 681-residue ectodomain, a 29-residue transmembrane domain, and a 52-residue cytoplasmic domain. 11 mutant nucleotides were found in beta6 gene coding region and 9 amino acids were changed. The nucleotide sequence similarity of integrin beta6 gene between rheses monkey, mouse, Norway rat, dog, guinea pig, human, bovine, sheep is 79.5%, 84.9%, 85.4%, 85.2%, 88.7%, 90.1%, 91.9% and 91.9%, and the amino acid sequence similarity is 93.5%, 88.2%, 88.5%, 88.3%, 91.0%, 92.8%, 93.3% and 93.4% respectively. This study will lay a foundation for understanding the interactions of FMDV with receptors.

Cloning and sequence analysis of cDNA encoding porcine alphav subunit for FMDV receptor / 生物工程学报

Receptors play a crucial role in determining the pathogenesis and tissue tropism of virus. Foot-and-mouth disease virus (FMDV) has been showed to use four integrins, alphavbeta1, alphavbeta3, alphavbeta6 and alphavbeta8 as receptors to initiate infection. In this study, the porcine integrin alphav gene was cloned by RT-PCR from the lung tissue of healed pig infected experimently with FMDV, and compared its nucleotide and deduced amino acid sequence with the av gene of other animals. The 3141bp cDNA of bovine integrin alphav encodes a polypeptide of 1046 amino acids consisting of a 30-residue putative signal peptide, a 955-residue ectodomain, a 29-residue transmembrane domain, and a 32-residue cytoplasmic domain. The ectodomain contains 11 potential N-linked glycosylation sites (NXT/NXS), 2 calcium binding domains (DX[D/N] XDGXXD) and 18 cysteine residues. The nucleotide sequence similarities of integrin alphav between pig and cattle, human, rheses monkey, house mouse, chicken, dog are 93.3%, 91.5%, 91.4%, 85.6%, 73.2% and 89.9% respectively; and the amino acid sequence similarities are 96.3%, 94.6%, 94.1%, 90.8%, 81.6% and 93.8%, respectively. The alphav gene of cattle and pig exhibited the highest sequence homology. It is possible that host tropism of FMDV may related to divergence in receptors among different species.

Nucleic Acid Sequence-Based Amplification and Its Applications in Viral Diagnosis / 中国生物工程杂志

Nucleic acid sequence-based amplification(NASBA) is a sensitive,isothermal,transcription-based amplification system specifically designed for the detection of RNA targets,which could amplify templete RNA in 2h under isothermal condition at about 42?C and without any special equipment.NASBA is now widely applicated in diagnosis of many pathogenic microorganism.It is mainly about principles and applications of NASBA in viral diagnosis.

Molecular Characteristics of cDNA Encoding Bactrian Camel ?6 Subunit for FMDV Receptor / 中国生物工程杂志

Receptors play a crucial role in determining the host specificity and tissue tropism of virus. Foot-and-mouth disease virus(FMDV)has been showed to use four integrins, ?v?1, ?v?3, ?v?6 and ?v?8 as receptors to initiate infection and ?v?6 functions as the major receptor.The cDNA encoding bactrian camel integrin ?6 from the lung tissue was cloned and sequenced. The 2367bp cDNA of bactrian camel integrin ?6 encodes a polypeptide of 788 amino acids consisting of a 26-residue putative signal peptide, a 681-residue ectodomain with 8 potential N-linked glycosylation sites and 58 cysteine residues, a 29-residue transmembrane domain, and a 52-residue cytoplasmic domain with a NPLY motif and 1 potential N-linked glycosylation site. The nucleotide sequence similarity of integrin ?6 between bactrian camel and cattle, pig, sheep, human, mouse, Norway rat is 91.1%、91.8%、90.6%、90.5%、83.7%、84.1%, and the amino acid sequence similarity is 94.3%、93.4%、93.4%、93.7%、88.7%、88.6%, respectively. The bactrian camel ?6 gene exhibited the higher sequence homology with the ?6 gene of cattle, pig and sheep, indicating their close genetic relationships. It is possible that host tropism of FMDV may related to divergence in ?6 receptors among different species.

Heparan Sulfate and Foot-and-mouth Disease Virus Infection / 微生物学通报

Receptors are primary determinant of viral tropism and disease pathogenesis.Heparan sulfates (HS)are ubiquitous,polyanionic carbohydrate chains linked to core proteins in cell membranes and ex- tracellular matrices of all eukaryotes.HS have also been demonstrated to function as receptors or co-receptors for a number of different viruses.To date,HS and four RGD-dependent integrins,?v?3,?v?6, ?v?1,and?v?8 have been reported to serve as receptors for Foot-and-mouth disease virus(FMDV).Different receptors may be used to interact with host cells during FMDV infection.Studies on the structure and function of receptors are very important for understanding the interaction between host cells and FMDV. Here,We mainly reviews the progress on the biological characteristics of HS and its roles in FMDV infection.

Integrin and Foot-and-mouth Disease Virus Infection / 微生物学通报

Integrins are a family of cell surface glycoproteins that contribute to a variety of biological functions, including cell growth, migration, proliferation and morphology. In addition, integrins also play the important roles in pathological process. Several viruses have been showed to use integrins as receptors or co-receptors to infect host cells.This article mainly reviews the progress on integrins and their roles in FMDV infection.