Bing du xue bao = Chinese journal of virology最新文献

To explore the mechanisms of influenza H7N9 virus pathogenesis, influenza H7N9 virus and H1N1 influenza A virus(H1N1pdm09)-infected A549 cellular models were established, and differential protein expression in A549 cells infected with the two strains were investigated.A549 cells were infected with H7N9 and H1N1pdm09influenza virus at a multiplicity of infection(MOI)of 0.001.The temporal response of A549 cells infected with the two strains was evaluated using the proteomics approaches(2DDIGE combined with MALDI-TOF-MS/MS)at 24,48 and 72hours post infection(hpi).There were 11,12 and 33proteins with significantly different expression at 24,48 and 72hpi,respectively.Compared with H1N1pdm09 infection, functional analysis revealed that the down-regulation of proteins in H7N9 infection including F-actin-capping protein subunit alpha-1(CapZ-α1), ornithine aminotransferase(OAT),poly(rC)-binding protein 1(PCBP1)and eukaryotic translation initiation factor 5A-1(eIF5A)produced cytopathic effects. The down-regulation of platelet-activating factor acetylhydrolaseIb subunit beta(PAFAH1B2)in H7N9-infection may be related to the clinical symptoms of patients infected by the influenza H7N9 virus.

China has the second highest number of rabies cases worldwide. There are millions of category III rabies exposure cases in China every year, which are treated with rabies immunoglobulin(RIG)and the rabies vaccine. The price of RIG is relatively expensive, and the application of RIG is relatively complicated. The rate of RIG use in post exposure prophylaxis(PEP)for rabies exposure category Ⅲ cases has remained low for a significant amount of time. Reducing the dosage of RIG could reduce the cost of PEP, while simplifying the use of RIG could make PEP easier. Together, these steps could improve the rate of RIG utilization in PEP. There are conflicting conclusions in studies of RIG on the immune effects of the rabies vaccine.Exploring the mechanism of action of RIG in the immune response to the rabies vaccine would help to explain the role of RIG in the immune effects mediated by the rabies vaccine. In this paper, the progress of research on the application of RIG is systematically reviewed in order to provide a reference for the formulation of new and more practical guidelines for the application of RIG.

Dog circovirus (DogCV) is a newly discovered mammalian circovirus. To investigate the genomic characteristics and genetic diversity of DogCV spreads in China, the first genome sequence of Chinese isolate, designated as JZ98/2014,was obtained by overlap PCR using the DNA extracted from dog serum as template for amplification. The nucleotide content and genome organization were subsequently analyzed. The results showed that the full-length genome of JZ98/2014 is 2063nt,and contains three major open reading frame: ORF V1 (encodes the 303 amino acid Rep protein),ORF C1(encodes the 270 amino acid Cap protein),and ORF C2(encodes 106 amino acids).JZ98/2014 shared 82.1%-89.5% homology with the complete genome sequences of DogCV isolates from America and Europe. The Rep gene and Cap gene of JZ98/2014 shared 82.1%-89.5%and 84.6%-89.1% homology, respectively, with the same genes from other DogCVs. Phylogenetic tree analysis indicated that there were several different genetic clades of DogCV spread in the world, and JZ98/2014 formed a clade by itself.

Interferon inducible transmembrane proteins(IFITMs)are restriction factors with broad-spectrum antiviral functions in infected cells. IFITM genes belong to a large subfamily of dispanins and have multiple functions, amongst which the antiviral functions are the main focus of study. IFITMs, especially IFITM3,can restrict the early replication of viruses such as avian influence virus, and, therefore, have become a hot topic in research in recent years. To date, studies have shown that IFITMs restrict virus invasion mainly through endosomal pathways, subsequently inhibiting viral replication. However, a detailed antiviral mechanism is still unclear. Here, we summarize the advances in IFITM research from recent years.

Respiratory syncytial virus(RSV)is a leading cause of lower respiratory tract disease. The major high risk population for RSV infection are<6month infants and elders with age older than 65 years. At present, BALB/c mice were wildly used as animal model for RSV infection, however there has no report about the comparison of different week-ages BALB/c mice after RSV infection. A different week-ages BALB/c mice model was described in this study to compare their susceptibility after RSV infection. Young(10weeks),middle aged(30weeks)and aged(60weeks)mice were intranasally infected with 106 or 107plaque-forming units (PFU) RSV, then clinical symptom, weight, RSV titer in nose/lung, histology and immunohistochemistry was examined. And age-related susceptibility was analyzed. A high-titer virus(107PFU)infection showed significant weight loss at 6-11 day post infection while 106 PFU didn’t lead to obvious weight change. In 10(7) PFU infected group, replication of virus in nose and lung was detected, the virus in lung located around pulmonary alveoli, and the hematoxylin eosin stain showed significant infiltration of inflammatory cells and pathological tissue damage. Mice trended to be more susceptible to RSV infection as the growth of age. Older mice experience more weight loss. Lung histology of older mice showed more serious bronchiolitis and increased number of inflammatory cells in alveolar spaced, and 60week-old mice tended to be the most significant. In this study, we have successfully established a different week-ages BALB/c mice model, which will serve as the basis for investigating antibody or vaccine and further infection mechanism research of RSV.

To obtain neutralizing high affinity human recombinant antibodies for antigenic site Ⅲ of rabies virus(RV)glycoprotein, we chose scFv phage display technology to optimize CR4098 with chain shuffling. Using pHAL14-CR4098 as vector, the combinatorial shuffling scFv antibody phage libraries were constructed to replace CR4098 light or heavy chain genes respectively by antibody genes derived from the blood of RV-vaccinated donors. After package by hyperphage, the chain shuffling scFv phage library was panned and selected by ELISA with purified rabies virus aG strain. The specific antibody was converted to full human IgG antibody with the VH/VK Express cassettes. Affinity and neutralizing test were performed to verify the function of the IgG molecules. Fourteen unique human ScFv antibodies specific for the glycoprotein of rabies virus were obtained by ELISA,IFA and DNA sequencing. Further tested showed that RV3A5 has a high affinity of 2.8×10(-9) M and high neutralizing activity to rabies virus both aG strains and CVS strains. Competitive ELISA showed that RV3A5 and CR4098for antigenic Site III competed with each other, indicating that they had overlapping or shared the epitope. Our results provide more candidates eligible for use in a mAb cocktail aimed at replacing RIG for rabies post-exposure prophylaxis.

To understand the prevalence and molecular typing of enterovirus D68 among children with severe acute respiratory infection(SARI)in Beijing and Shanghai,259 respiratory samples were collected from in Beijing during 2008-2010,and 441 respiratory samples were collected in Shanghai city between 2013and2014.All the samples were used for the screening of EV-D68 by nest RT-PCR and sequencing, and then EV-D68-positive samples were used for the complete genome sequencing through overlapping PCR. All available EV-D68full-length genomes collected from GenBank were used for phylogenetic analysis and comparison of EV-D68 types prevalent in China and America. One(0.4%)from 259 respiratory samples in Beijing was positive for EV-D68,and 4(0.9%)among the 441 samples from Shanghai were positive for EV-D68.Phylogenetic analysis of full length genome indicated that the EV-D68 prevalent in Beijing belong to Clade A2 and Clade B2,different from the American popular strains(Clade A1,Clade B1,Clade B4 and Clade B5).Partial sequence analysis declared phylogenetic conflict among different gene sequences. We concluded that the prevalence rate of EV-D68 among SARI Children in Beijing and Shanghai currently was lower(5/700;<1%),and the EV-D68 genotype prevalent in China and America belong to different clusters. Partial sequence analysis indicated that intratypic recombinant events may occur in EV-D68 prevalent in China.

Enterovirus 71 (EV71) is a major agent of hand, foot, and mouth disease in children under five years of age. In some cases,infection with EV71 can result in herpangina, pulmonary edema and/or brainstem encephalitis. In recent years, many advances have been made towards an understanding of EV71 pathogenesis. In this review, we summarize the cell types targeted by EV71,the activation of signaling pathways, the innate antiviral immune response and immune evasion by EV71 to better understand the immunopathogenesis of EV71 and to aid in the development of antiviral drugs.

To investigate the in vitro anti-HIV-1effect of the aqueous extracts of Cordyceps sinensis. The aqueous stroma and sclerotium extracts were isolated from the fresh and dry Cordyceps sinensis specimen, respectively. The CCK-8test and the TZM-bl pseudovirus assay were used to examine the in-vitro cytotoxicity and anti-HIV-1activities of extracts. In addition, the reverse-transcriptase enzyme-activity assay and the surface plasma resonance(SPR)technology were taken to study the inhibition on the activity of reverse transcriptase and interaction with Vif protein. All 5aqueous extracts of Cordyceps sinensis exhibited in vitro anti-HIV-1effects,extracts from the fresh fungus showed more potent effect in inhibiting reverse-transcriptase activity than the dry fungus. Furthermore, a strong interaction was observed between the fresh stroma extract and Vif protein.The study clarified that the in vitro anti-HIV-1activity of the aqueous extracts of Cordyceps sinensis, may be mediated through inhibition of reverse-transcriptase activity and interaction with Vif protein.

To study the genetic characterization and amino acid mutation of hemagglutinin protein of four genotypes of wild type measles Viruses isolated in 2013 and 2014year,in China, including H1,B3,D8 and D9.Four genotype isolates of H1,D8,D9 and B3measles viruses were selected, and RNA of MV isolates were extracted. The complete sequence of hemagglutinin (1854nt) were amplified by RT-PCR and sequenced and Sequencher5.0was used to splice sequence. Phylogenetic analysis and the diversity of gene and amino acid were done by MEGA version 5.0,compared with 24 representative strains, repectively 4 H a sub-genotype strains,8D8 genotype strains,2D9 genotype strains,8B3 genotype strains and 2Chinese vaccine Strains, which were downloaded from GenBank. The homology of H gene nucleotide sequence and amino acid between the four genotype measles virus strains including H1,B3,D8,D9 and A genotype strains were respectively 94.2%-96.7%and 95.4%-96.7%and there were 20-28 amino acids difference between them; And the homology of H gene nucleotide sequence between Beijing14-1(H1a)and A genotype vaccine strains was 97.7%-98.2%.The N-glycosylation site in 240th was losen because of mutation. The homology of H gene nucleotide sequence and amino acid between the four genotype measles virus strains including H1,B3,D8,D9 and A genotype strains were high, and the Chinese vaccine can effectively prevent infection caused by H1asub-genotype,D8,D9 and B3imported genotypes virus strains.