Enterovirus 71 (EV71) is a major causative agent of hand, foot and mouth disease (HFMD). belongs to family Picornaviridae, genus Enterovirus, species A. EV71 infection usually affects subjects aged <5 years. HFMD caused by EV71 infection is usually mild in children. However, in some cases EV71 infection can lead to severe neurogenic disease and even death. EV71 infection has caused epidemic worldwide (especially in the Asia Pacific). HFMD caused by EV71 has become a major public-health prol lem across the Asia Pacific. In EV71 infection, the pathogenesis is determined by viral and host factor, Here, we review research on host susceptibility and how EV71 suppresses immune and intracellular ri
Animals ; Enterovirus A, Human ; genetics ; pathogenicity ; physiology ; Hand, Foot and Mouth Disease ; virology ; Humans ; Virulence ; Virus Attachment ; Virus Replication

The special nucleic acid fragments, 5' untranslated region (5' UTR) and internal ribosome entry site (IRES) of foot-and-mouth disease virus (FMDV), which interact with the capsid proteins, were selected as scaffolds to investigate the assembly efficiency of foot-and-mouth disease (FMD) virus-like particles (VLPs). The assembled product was characterized by evaluation of particle size, surface potential, gel retardation assay, nuclease digestion experiments, size-exclusion chromatography, transmission electron microscopy and circular dichroism analysis. The results confirmed that the 5' UTR and IRES of FMDV co-assembled with the FMD VLPs and facilitated the assembly efficiency of FMD-VLPs. It demonstrates that the assembly efficiency of 75S particles of VLPs-5'UTR was significantly higher than those of the VLPs (P<0.001) and VLPs-IRES group (P<0.01). Comparatively the assembly efficiency of 12S particles of VLPs-IRES was significantly higher than those of the VLPs (P<0.000 1) and VLPs-5'UTR (P<0.000 1). It showed that the 5' UTR represented more effective in facilitating the assembly of VLPs. This study proposes an optimized strategy for improving the assembly efficiency of VLPs for the development of VLPs vaccine.
5' Untranslated Regions ; Capsid Proteins/metabolism* ; Foot-and-Mouth Disease Virus/physiology* ; Internal Ribosome Entry Sites ; Nucleic Acids/metabolism* ; Virus Assembly

Integrin alphavbeta3 plays a major role in various signaling pathways, cell apoptosis, and tumor angiogenesis. To examine the functions and roles of alphavbeta3 integrin, a stable CHO-677 cell line expressing the murine alphavbeta3 heterodimer (designated as "CHO-677-malphavbeta3" cells) was established using a highly efficient lentiviral-mediated gene transfer technique. Integrin subunits alphav and beta3 were detected at the gene and protein levels by polymerase chain reaction (PCR) and indirect immunofluorescent assay (IFA), respectively, in the CHO-677-malphavbeta3 cell line at the 20th passage, implying that these genes were successfully introduced into the CHO-677 cells and expressed stably. A plaque-forming assay, 50% tissue culture infective dose (TCID50), real-time quantitative reverse transcription-PCR, and IFA were used to detect the replication levels of Foot-and-mouth disease virus (FMDV) in the CHO-677-malphavbeta3 cell line. After infection with FMDV/O/ZK/93, the cell line showed a significant increase in viral RNA and protein compared with CHO-677 cells. These findings suggest that we successfully established a stable alphavbeta3-receptor-expressing cell line with increased susceptibility to FMDV. This cell line will be very useful for further investigation of alphavbeta3 integrin, and as a cell model for FMDV research.
Animals ; Animals, Suckling ; CHO Cells ; Cloning, Molecular ; Cricetulus ; DNA, Complementary/genetics/metabolism ; Disease Susceptibility/virology ; Foot-and-Mouth Disease/*genetics/virology ; Foot-and-Mouth Disease Virus/*physiology ; Integrin alphaVbeta3/*genetics/metabolism ; Mice

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.
Amino Acid Sequence ; Animals ; Base Sequence ; Cattle ; Cloning, Molecular ; DNA, Complementary ; genetics ; Foot-and-Mouth Disease Virus ; physiology ; Integrin alphaV ; genetics ; Macaca mulatta ; Molecular Sequence Data ; Receptors, Virus ; genetics ; metabolism ; Sequence Analysis ; Swine ; genetics

We produced beta1 gene which is about 2400 bp by reverse transcription polymerase chain reaction (RT-PCR) from bovine trachea, reclaimed and purified, then cloned the amplified fragment to pGEM-T easy vector, confirmed by sequencing. The immune-dominant epitope of beta1 gene was chosen by computer analysis and then syncretized ligand-binding domain from 346 bp to 843 bp of ecytoplasm with six histidine, expressed LBD protein massly in E. coli BL21 (DE3), and identified by SDS-PAGE. The fusion protein was purified with Ni-NTA affinity chromatography and immunized New Zealand rabbits preparing of its polyclonal antibody, the specific antibody titer was above 1:12,800 detected by indirect ELISA, the result of Western blot showed that this antibody could be recognized by LBD fusion protein.
Animals ; Antibodies, Monoclonal ; biosynthesis ; Cattle ; Escherichia coli ; genetics ; metabolism ; Foot-and-Mouth Disease Virus ; physiology ; Integrin alpha1beta1 ; biosynthesis ; genetics ; immunology ; Ligands ; Protein Binding ; Protein Interaction Domains and Motifs ; Rabbits ; Receptors, Virus ; genetics ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology

Human enterovirus 71 (EV71) is one of the major etiological agents for the hand, foot, and month disease (HFMD) and is causing frequent, widespread occurrence in the mainland of China. The single positive-stranded RNA genome of EV71 is translated into a single polyprotein which is autocleavaged into structural and nonstructural proteins. The functions of many nonstructural proteins characterized in the life cycle of virus are potential targets for blocking viral replication. This article reviews the studies of the structures and functions of nonstructural proteins of EV71 and the anti-enterovirus 71 drugs targeting on these nonstructural proteins.
Antiviral Agents ; pharmacology ; Enterovirus A, Human ; enzymology ; genetics ; isolation & purification ; Hand, Foot and Mouth Disease ; drug therapy ; virology ; Humans ; Molecular Targeted Therapy ; Peptide Hydrolases ; chemistry ; metabolism ; physiology ; Protein Kinase Inhibitors ; pharmacology ; RNA, Viral ; genetics ; Viral Nonstructural Proteins ; chemistry ; metabolism ; physiology ; Virus Replication ; drug effects