Porcine parvovirus(PPV) is one of the major causes of reproductive failure in pigs, which poses a great threat to the pig breeding industry and results in tremendous economic losses worldwide. Autophagy is the biologi...Porcine parvovirus(PPV) is one of the major causes of reproductive failure in pigs, which poses a great threat to the pig breeding industry and results in tremendous economic losses worldwide. Autophagy is the biological process of cell self-defense and self-protection. Despite many viruses can cause cell autophagy, when they enter cell or copied, the relationship between autophagy and PPV infection has not been reported. In this study, impact of autophagy after swine testicular(ST) cells infected by PPV was studied. Autophagy was demonstrated by the effective replication of PPV through transmission electron microscopy, immunofluorescence and western blot analysis. Moreover, autophagy was confirmed to benefit PPV replication by real-time fluorescence quantitative PCR and determination of median tissue culture infective dose(TCID). For the first time, the complex interaction between PPV infection and autophagy was explored in this study. It indicated that PPV could induce autophagy in ST cells, which in turn facilitated its own replication, which might be one of the mechanisms of the virus infection. These findings could facilitate the study of the pathogenesis of PPV infection and provide new insight into the development of effective therapeutic strategies.展开更多
The objective of this study was to construct the infectious clone of encephalomyocarditis virus (EMCV) BJC3 strain.The genomic cDNA of the virus was amplified by three overlapping segments using RT-PCR,and cloned into...The objective of this study was to construct the infectious clone of encephalomyocarditis virus (EMCV) BJC3 strain.The genomic cDNA of the virus was amplified by three overlapping segments using RT-PCR,and cloned into low-copy plasmid pWSK29 to construct the full-length cDNA clone pWSKBJC3/ w.The pWSKBJC3/w was in vitro transcribed and transfected into BHK-21 cells to rescue the virus.The results showed that the full-length cDNA clone was infectious and the virus could be rescued in BHK-21 cells.The rescued virus designated RvBJC3W was identified by RT-PCR and indirect immunofluorescence assay(IFA).The rescued virus had similar growth characteristics to its parental virus BJC3 and retained pathogenicity for mice.Our results indicate that the first infectious cDNA clone of EMCV in China has been successfully established and provides an essential tool for investigating the molecular basis of pathogenicity of EMCV.展开更多
To construct a recombinant adenovirus shuttle plasmid pDC315-H5HA-EGFP,the HA gene of A/Swine/Fujian/1/2001(H5N1) was amplified by RT-PCR and then inserted into adenovirus shuttle plasmid pDC315.A replication-defectiv...To construct a recombinant adenovirus shuttle plasmid pDC315-H5HA-EGFP,the HA gene of A/Swine/Fujian/1/2001(H5N1) was amplified by RT-PCR and then inserted into adenovirus shuttle plasmid pDC315.A replication-defective recombinant adenovirus expressing the HA gene(rAd-H5HA-EGFP) was generated by co-transfecting the recombinant shuttle plasmid pDC315-H5HA-EGFP and the genomic plasmid pBHGlox△E1,E3Cre in HEK293 cells.The recombinant adenovirus was confirmed by PCR,RT-PCR and Western blot assay.These results demonstrated that HA protein was properly expressed by the rAd-H5HA-EGFP in HEK293 cells and had natural biological activities.The TCID<sub>50</sub> of the rAd-H5HA- EGFP was assessed to be 2.26×10<sup>10</sup>/mL after propagation and purification.Immunization of BALB/ c mice indicated that rAd-H5HA-EGFP induced HI antibodies and protected mice from replication of the challenge virus in their lungs.展开更多
There are a total of more than 40 reported maize viral diseases worldwide. Five of them have reportedly occurred in China. They are maize rough dwarf disease, maize dwarf mosaic disease, maize streak dwarf disease, ma...There are a total of more than 40 reported maize viral diseases worldwide. Five of them have reportedly occurred in China. They are maize rough dwarf disease, maize dwarf mosaic disease, maize streak dwarf disease, maize crimson leaf disease, maize wallaby ear disease and corn lethal necrosis disease. This paper reviewed their occurrence and distribution as well as virus identification techniques in order to provide a basis for virus identification and diagnosis in corn production.展开更多
The small envelope protein （E） gene of avian infectious bronchitis virus （IBV） M41 strain was cloned, and then it was subcloned into prokaryotic expressing vector pGEX-6P-1. The recombinant plasmid was transformed...The small envelope protein （E） gene of avian infectious bronchitis virus （IBV） M41 strain was cloned, and then it was subcloned into prokaryotic expressing vector pGEX-6P-1. The recombinant plasmid was transformed into E.coli. BL21 and induced by IPTG. SDS-PAGE result showed that when objective protein fused with GST （about 20 ku）, the relative molecular mass of fusion protein was 38 ku. It indicated that objective protein was about 12.4 ku. The result showed that E protein was expressed successfully, it was useful to the subsequent E protein research.展开更多
Accurate differentiation of the pathogenic phenotypes of infectious bursal disease viruses(IBDVs) will instruct effective vaccination programs and improve the study of the molecular epidemiology of IBDVs. In this stud...Accurate differentiation of the pathogenic phenotypes of infectious bursal disease viruses(IBDVs) will instruct effective vaccination programs and improve the study of the molecular epidemiology of IBDVs. In this study, an 833 bp hypervariable nucleotide region was identified in VP2 genes of known IBDVs with different virulences through multiple sequence alignment.Moreover, using NEBcutter software analysis, two restriction enzyme sites, SpeⅠ(generating 531 and 302 bp fragments) and StuⅠ(generating 242 and 591 bp fragments) were found presented in very virulent but not attenuated IBDVs. Moreover, the restriction enzyme site SacⅠ(generating 218 and 615 bp fragments) presented in attenuated IBDVs but not very virulent IBDVs. Therefore,a reverse-transcription(RT)-PCR combined with a restriction fragment length polymorphism(RFLP) assay was developed to differentiate attenuated and very virulent IBDVs. The RT-PCR assay was used to confirm 282 IBDV positive samples from 310 suspicious dead chicken samples. The 60 IBDV positive samples were used to evaluate the assay, followed by confirmation via gene sequencing and histopathological examinations of the bursas of Fabricius from chickens infected by these IBDVs. The results showed that 24 viral strains with SpeⅠand StuⅠsites were very virulent, causing severe pathological damage in the bursas of Fabricius, while36 viral strains with the SacⅠsite were attenuated IBDVs, exhibiting only slight pathological damage. The combined RT-PCR and RFLP assay provided a useful approach for differentiating the pathogenic phenotypes of IBDVs.展开更多
Chinese isolate of transmissible gastroenteritis virus(TGEV)was propagated and harvested in swine testicle(ST)cells.Two pairs of primers were designed according to the published sequence with Oligo 4.1 and DNasis soft...Chinese isolate of transmissible gastroenteritis virus(TGEV)was propagated and harvested in swine testicle(ST)cells.Two pairs of primers were designed according to the published sequence with Oligo 4.1 and DNasis softwares.The products of RT-PCR were named Sa and Sb,of 2.3kb and 2.1kb respectively.Sa was inserted in EcoR I and Kpn I sites after Sb was cloned in Kpn I and Pst I sites of the same pUC18 plasmid.The recombinant designated pUC-S was verified and analyzed by corresponding restriction endonuclease(RE)and nested PCR on the basis of genetic sites of S gene and physical map of pUC18 plasmid,which was identified as S gene from Chinese isolate of TGEV.展开更多
Garlic virus infection is an important disease which affects garlic production,with the increasing years of planting,harm of virus is serious year by year,which seriously affect yield and quality of garlic.In order to...Garlic virus infection is an important disease which affects garlic production,with the increasing years of planting,harm of virus is serious year by year,which seriously affect yield and quality of garlic.In order to know the garlic virus effectively,the paper reviewed the research situation of several important garlic virus in virus species,origin,distribution,host range,symptom,route of transmission,classification,genome and detection technique and the prevention technology of garlic viruses.At the same ...展开更多
The HA1 gene of H3N2 subtype swine influenza virus(SIV)was cloned into the expression plasmid pET-30a,the recombinant plasmid was named pET-HAl.This was transformed into E.coli BL21(DE3),and expressed by induction wit...The HA1 gene of H3N2 subtype swine influenza virus(SIV)was cloned into the expression plasmid pET-30a,the recombinant plasmid was named pET-HAl.This was transformed into E.coli BL21(DE3),and expressed by induction with IPTG.The expressed HA protein was identified by SDS-PAGE and Western blotting which showed the protein to be 42kDa and was immunoreactive.The purified HA protein was used to establish the indirect ELIS A for detection of the antibodies,specifically against the H3 subtype of SIV.The assay has excellent specificity,sensitivity and reproducibility.When 96 serum samples,randomly collected from the field,were evaluated in parallel by this new ELISA using recombinant HA1 and a routine HI test,the coincidental rate between the two tests was 86.5%.These results show that the recombinant HAl-based ELISA is specific,sensitive and easy to perform for the serological diagnosis of SIV infection.展开更多
OBJECTIVE How infection of Herpes simplex virus typeⅠ(HSV-1) induces enhancement of autophagy.MEHTODS The wild type HSV-1 strain Kos 1.1 was propagated in Vero cells and purified.SK-N-SH cells seeded in DMEM/F12 were...OBJECTIVE How infection of Herpes simplex virus typeⅠ(HSV-1) induces enhancement of autophagy.MEHTODS The wild type HSV-1 strain Kos 1.1 was propagated in Vero cells and purified.SK-N-SH cells seeded in DMEM/F12 were exposed to HSV-1 with 6 h or 12 h and multiplicity of infection(MOI) for 10 or 40 in each experiment.The infectious titers of the HSV-1 samples were determined by plaque assays.MDC staining to test the number of autophagosome within the cell after infection with time and moi was indicated in each experiment.At the molecular level,Western blotting and immunofluorescence analyses were done to study the expression of the proteins related to the cell autophagy.The mRNA transcribed from the gene related to autophagy was quantified by reverse transcription followed by real-time PCR.After intranasal infection of different transgenic mice,immunoflurorence studies were done to detected the expression of Aβ42 and proteins related to autophagy from the brain sections.Morris water maze experiment was performed to test the change of spatial learning and memory between different transgenic mice.RESULTS SK-N-SH cell showed time-and moi-dependent increase of MDC positive staining after HSV-1 infection.Western blotting analysis showed that LC3-Ⅱ was less in mock-infected cells but it was detected after 12 h from 10 to 40 moi HSV-1 infected cells.The level increased in a viral concentration-dependent manner.In agreement with the Western blotting results,direct fluorescence microscopy revealed that the signals of LC3 were consistent with their localization on autophagic compartments.P62,another protein related to autophagoysome formation,also increased with MOI.15 ku fragment of intracellular apolipoproteins E(APOE) protein increased after infection,but at the mRNA level it remained the same.The expression of APP showed less decrease but intracellular Aβ42 increased significantly compared with the mock group.Within the brain,after intranasal infection for 7 d,autophagy related proteins LC3 b and P62 increased as well,at the same time Aβ42 was found co-localized with LC3 b within the cell.Behavior test revealed that 17-month-old APOE4 mice had pool spatial learning and memory after infection compared with other groups.CONCLUSION HSV-1 induces an autophagic response and accelerates the fragmentation of APOE protein.展开更多
Objective:It intended to examine whether there is BDV infection in the human tumor tissues of central nervous system in China and investigate the correlation between BDV infection and tumors of central nervous system....Objective:It intended to examine whether there is BDV infection in the human tumor tissues of central nervous system in China and investigate the correlation between BDV infection and tumors of central nervous system.Methods:Nested reverse transcriptase polymerase chain reaction(nRT-PCR)and fluorescence quantitative polymerase chain reaction(FQ-PCR)was used to detect the BDV p24 fragments in 60 samples of human tumor tissues of central nervous system and 14 normal brain tissues.Results:The study indicated the positive rate of the BDV p24 fragment in human tumor tissues of the central nervous system(6.67%)was higher than that in normal brain tissues(0),but no statistical significance(P>0.05).Conclusion:It suggests that the BDV infection is present in the human tumor tissues of central nervous system in China, while the sample size wasn't large enough and we could not certify the possible correlation between BDV infection and cenfral nervous system tumors.展开更多
We present a rare challenging case of metastatic non-small cell lung cancer with Epstein-Barr virus positivity that was also diagnosed with pulmonary tuberculosis at the same time. Palliative chemotherapy gemcitabine ...We present a rare challenging case of metastatic non-small cell lung cancer with Epstein-Barr virus positivity that was also diagnosed with pulmonary tuberculosis at the same time. Palliative chemotherapy gemcitabine and carboplatin was started after two weeks of anti-tuberculosis treatment with the hopes that this period would be sufficient to keep acid fast bacilli non-viable to minimise risk of tuberculosis re-activation due to chemotherapy induced immunosuppression. She completed four cycles of chemotherapy and six months of anti-tuberculosis treatment with good results and minimal side effects. Two years later, there was disease recurrence in cervical and mediastinal lymph nodes which was treated with local treatment i.e. surgery and palliative radiotherapy. It has been two years since last radiotherapy and overall more than five years since diagnosis with no active disease at present. Given the complexity and rarity of this case, significant multidisciplinary team involvement, including oncologists and radiation oncologists, pulmonologists with special interest in tuberculosis and pathologists was necessary throughout.展开更多
Preliminary study has been made to test wether three strains McAb（1B1,5D<sub>6</sub>, 6D<sub>8</sub>）are against the same antigen determinant.Througn ELISA additive and competition expeiments...Preliminary study has been made to test wether three strains McAb（1B1,5D<sub>6</sub>, 6D<sub>8</sub>）are against the same antigen determinant.Througn ELISA additive and competition expeiments,itproved that these three strains are against different antigen determinant.The result of positiveserum antigen component analysis with 2 strains IBDV McAb showed that sample IBD positiveserum had obvious inhibition against combination of 5D<sub>6</sub> McAb with corresponding antigen.Theresults of substitution of corresponding component in ELISA inhibition experiment and compari-son of non-IBD serum （SPF chicken serum,ND,MD,IA positive serum）proved that IBD anti-serum was the only one showing inhibition against 5D<sub>6</sub> McAb.Comparison with AGP and electro-microscope observation showed that ELISA inhibition experiment was characterised by high-specificity,rapidity and sensitiveness.799 serum samples were tested with ELISA inhibition anddouble immunodiffusion（AGP） experiments.ELISA had gotten 486 positive,with positive rate of60.83%;and AGP 334。展开更多
Classical swine fever virus(CSFV) is the causative agent of classical swine fever, a highly contagious disease of pigs. But there is little information on the recombination in natural populations of CSFVs. Therefore, ...Classical swine fever virus(CSFV) is the causative agent of classical swine fever, a highly contagious disease of pigs. But there is little information on the recombination in natural populations of CSFVs. Therefore, a phylogenetic analysis of 62 fulllength genome CSFV strains, isolated from all over the world, was performed to detect potential recombination events, with the recombinant sequences being analyzed with the SimPlot and RDP programs. The results identified a mosaic virus, Chinese CSFV HCLV(2)(AF091507.1), which is the one naturally emerged recombinant CSFV with two recombination breakpoints at 2 484 and 2 900 bp of the genome alignment. Its two putative parental-like strains were CSFV Shimen(AF092448.2) and CSFV strain C/HVRI(AY805221.1). This work demonstrated that homologous recombination did occur in natural CSFV populations. It had significant implications for understanding the molecular epidemiology of CSFV, and revealed that recombination was an important factor for high genetic diversities of CSFV.展开更多
The study was aimed at establishing an indirect ELISA for epidemiological investigation of hepatitis E viral(HEV) infection in pigs from the major pig-producing regions of Zhejiang Province. The gene fragment covering...The study was aimed at establishing an indirect ELISA for epidemiological investigation of hepatitis E viral(HEV) infection in pigs from the major pig-producing regions of Zhejiang Province. The gene fragment covering the immunogenic epitopes of HEV ORF2 was synthesized and expressed in Escherichia coli.Western blot analysis revealed that the purified protein reacted to HEV positive sera,but not to positive sera from some other common viruses that infect pigs.An indirect ELISA system was then developed using truncated HEV ORF2 protein as the coating antigen and had diagnostic accuracy of 91.5% as compared with a diagnostic kit for HEV antibodies.A total of 1 330 serum samples were collected from 46 pig farms in Zhejiang Province from 2005-2008 and tested for sero-prevalence of HEV using the indirect ELISA.The average HEV-positive rate was 55.7%(741/1 330).The positive rate of 2005 and 2006 was 62.7%(175/279) and 61.4%(301/490) respectively,much higher than those of 2007(43.0%,59/137) and 2008(48.6%,206/424).Pigs aged 66-100 days had a statistically higher positive rate(58.2%,110/189) when compared to that of pigs aged 30-65 days(39.7%,73/184) or 101-160 days(44.1%,83/188).Only three herds in the study were HEV antibody-negative,indicating high sero-prevalence of HEV in the pig populations in Zhejiang Province.展开更多
Porcine reproductive and respiratory syndrome virus(PRRSV)GP4 protein was prokaryotically expressed,and used as an antigen to immunize six-week-old BALB/c female mice.With conventional cell fusion method,an anti-PRRSV...Porcine reproductive and respiratory syndrome virus(PRRSV)GP4 protein was prokaryotically expressed,and used as an antigen to immunize six-week-old BALB/c female mice.With conventional cell fusion method,an anti-PRRSV GP4 protein monoclonal antibody(Mab)5F12 was successfully prepared.It was identified as IgG2b subclass and had better stability and specificity,which not only responded with recombinant PRRSV GP4 protein,but also with PRRSV.Phage display technique had varieties of applications,in particular,the identification of key antigen epitopes for the development of therapeutic and diagnostic reagents and vaccines.In this study,Mab-5F12 was used as the target for biopanning a 12-mer phage random peptide library.After four rounds of biopanning,two phage-displayed peptides,named P-A and P-G(AKFEVCSPVVLG and GVNQENMLHFSF)were identified that recognized Mab-5F12 specifically.Sequence analysis showed that one or more of the peptides exhibited partial sequence similarity to the native GP4 protein sequence,which corresponded to 69-80 and 84-95 aa segments of the HP-PRRSV GP4 protein.Furthermore,real-time quantitative RT-PCR and indirect immunofluorescence assay indicated consistently the abilities of P-A and P-G to block viral infection in Marc-145 cells and they could function as antiviral agents for PRRSV.展开更多
Chikungunya fever(CHIKF)is an arboviral disease that typically consists of an acute illness with fever,skin rash,and incapacitating arthralgia.The causative agent of CHIKF is Chikungunya virus(CHIKV),an alphavirus tha...Chikungunya fever(CHIKF)is an arboviral disease that typically consists of an acute illness with fever,skin rash,and incapacitating arthralgia.The causative agent of CHIKF is Chikungunya virus(CHIKV),an alphavirus that is transmitted by the Aedes mosquitoes.Despite the re-emergence of CHIKV as an epidemic threat,there is no approved effective anti-viral treatment currently available for CHIKV.In our preliminary studies,selected small molecule inhibitors of arboviruses related to CHIKV were investigated and this led us to identify compounds with thieno[3,2-b]pyrrole scaffold as hits.Building on the discovery of our best hit compounds,5-carboxylic acid thieno[3,2-b]pyrrole 1 and 5-carboxamide thieno[3,2-b]pyrrole 2,the main aim of this study is to optimize their anti-viral activities by synthesizing analogs of thieno[3,2-b]pyrroles 1 and 2 and examine their activities against CHIKV.In these two parallel optimization studies,we synthesized two series of thieno[3,2-b]pyrroles,namely the 5-carboxylic acids and 5-carboxamides that possessed a variety of substituents at N4,C2,C6 or C5positions of the thieno[3,2-b]pyrrole scaffold.These compounds were then examined for their cytotoxicity effects and anti-viral activities using a luminescence-labelled CHIKV infectious clone.The most potent compound in our studies was found in the 5-carboxamide series.The synthesis,biological activity and structure-activity relationship(SAR)will be presented and discussed in detail.展开更多
Influenza virus infection is a global public health issue.The effectiveness of antiviral agents for influenza has been limited by the emergence of drugresistant virus strains.Therefore,there is an urgent need to ident...Influenza virus infection is a global public health issue.The effectiveness of antiviral agents for influenza has been limited by the emergence of drugresistant virus strains.Therefore,there is an urgent need to identify novel antiviral therapies.Our previous studies have found that Cryptoporus volvatus extract could potently inhibit influenza virus replication in vitro and in vivo.However,the effective component of Cryptoporus volvatus which mediated the antiviral activity hasn′t been identified.Here,we identified a novel anti-influenza molecule,cryptoporic acid E(CAE),from Cryptoporus volvatus.Our results showed that CAE had broad-spectrum anti-influenza activity against 2009 pandemic strain A/Beijing/07/2009(H1N1/09),seasonal strain A/Jiangxi/262/05(H3N2),mouse adapted strains A/WSN/33(H1N1)and A/PR8/34(H1N1).We further investigated the mode of CAE action,and found that CAE directlyattenuated influenza virus infectivity.Time-course-analysis indicated that CAE exerted its inhibition mainly at middle stage of the replication cycle of influenza virus.Subsequently,we confirmed that CAE blocked virus RNA replication and transcription in MDCK cells and CAE repressed influenza virus RNA polymerase activity.In addition,we found that CAE impaired influenza virus infectivity by directly targeting virus particles.Our data suggest that CAE is a major effective component of Cryptoporus volvatus and might be a potential candidate for the development of a new anti-influenza virus therapy.展开更多
Citrus tristeza virus （CTV）, the most devastating viral pathogen in citrus, causes tremendous economic losses to citrus industry worldwide. The CTV isolates exhibit variable pathogenicities on their hosts indicating...Citrus tristeza virus （CTV）, the most devastating viral pathogen in citrus, causes tremendous economic losses to citrus industry worldwide. The CTV isolates exhibit variable pathogenicities on their hosts indicating a mixed population of the CTV in nature. Several fragments within the CTV genome have been used for studying the genetic diversity of the CTV, however, the best region for rapid the CTV strain differentiation is still absent at present. In present study, a systemic analysis was carried out to evaluate the best region within the CTV genome for rapid CTV strain differentiation. Results of our study showed that the major coat protein （CP） coding region was the best region for this purpose. Using pair-wise distance frequency distribution plot, a reasonable genetic distance cut-off value was set for the CTV CP gene for the CTV strain differentiation. Using this criterion, eight CTV strains, including seven well characterized and a new strain, were successfully differentiated using 537 CTV isolates reported from 38 countries. The global strain distribution pattern was then determined and discussed. Our results also provided a new insight into the evolution and spreading of the virus, as well as the information for developing proper disease management strategy.展开更多
基金Supported by the National Natural Science Foundation of China(31372438,31201911)
文摘Porcine parvovirus(PPV) is one of the major causes of reproductive failure in pigs, which poses a great threat to the pig breeding industry and results in tremendous economic losses worldwide. Autophagy is the biological process of cell self-defense and self-protection. Despite many viruses can cause cell autophagy, when they enter cell or copied, the relationship between autophagy and PPV infection has not been reported. In this study, impact of autophagy after swine testicular(ST) cells infected by PPV was studied. Autophagy was demonstrated by the effective replication of PPV through transmission electron microscopy, immunofluorescence and western blot analysis. Moreover, autophagy was confirmed to benefit PPV replication by real-time fluorescence quantitative PCR and determination of median tissue culture infective dose(TCID). For the first time, the complex interaction between PPV infection and autophagy was explored in this study. It indicated that PPV could induce autophagy in ST cells, which in turn facilitated its own replication, which might be one of the mechanisms of the virus infection. These findings could facilitate the study of the pathogenesis of PPV infection and provide new insight into the development of effective therapeutic strategies.
基金supported by the Key Project of National Natural Science Foundation of China(30530550)
文摘The objective of this study was to construct the infectious clone of encephalomyocarditis virus (EMCV) BJC3 strain.The genomic cDNA of the virus was amplified by three overlapping segments using RT-PCR,and cloned into low-copy plasmid pWSK29 to construct the full-length cDNA clone pWSKBJC3/ w.The pWSKBJC3/w was in vitro transcribed and transfected into BHK-21 cells to rescue the virus.The results showed that the full-length cDNA clone was infectious and the virus could be rescued in BHK-21 cells.The rescued virus designated RvBJC3W was identified by RT-PCR and indirect immunofluorescence assay(IFA).The rescued virus had similar growth characteristics to its parental virus BJC3 and retained pathogenicity for mice.Our results indicate that the first infectious cDNA clone of EMCV in China has been successfully established and provides an essential tool for investigating the molecular basis of pathogenicity of EMCV.
基金supported by the Chinese National S&T Plan(2004BA519A55)Scientific Research Program of State Key Laboratory of Veterinary Biotechnology(NKLVBP200818)
文摘To construct a recombinant adenovirus shuttle plasmid pDC315-H5HA-EGFP,the HA gene of A/Swine/Fujian/1/2001(H5N1) was amplified by RT-PCR and then inserted into adenovirus shuttle plasmid pDC315.A replication-defective recombinant adenovirus expressing the HA gene(rAd-H5HA-EGFP) was generated by co-transfecting the recombinant shuttle plasmid pDC315-H5HA-EGFP and the genomic plasmid pBHGlox△E1,E3Cre in HEK293 cells.The recombinant adenovirus was confirmed by PCR,RT-PCR and Western blot assay.These results demonstrated that HA protein was properly expressed by the rAd-H5HA-EGFP in HEK293 cells and had natural biological activities.The TCID<sub>50</sub> of the rAd-H5HA- EGFP was assessed to be 2.26×10<sup>10</sup>/mL after propagation and purification.Immunization of BALB/ c mice indicated that rAd-H5HA-EGFP induced HI antibodies and protected mice from replication of the challenge virus in their lungs.
基金Supported by the Finance Department of Hebei Province(A2012120104)
文摘There are a total of more than 40 reported maize viral diseases worldwide. Five of them have reportedly occurred in China. They are maize rough dwarf disease, maize dwarf mosaic disease, maize streak dwarf disease, maize crimson leaf disease, maize wallaby ear disease and corn lethal necrosis disease. This paper reviewed their occurrence and distribution as well as virus identification techniques in order to provide a basis for virus identification and diagnosis in corn production.
文摘The small envelope protein （E） gene of avian infectious bronchitis virus （IBV） M41 strain was cloned, and then it was subcloned into prokaryotic expressing vector pGEX-6P-1. The recombinant plasmid was transformed into E.coli. BL21 and induced by IPTG. SDS-PAGE result showed that when objective protein fused with GST （about 20 ku）, the relative molecular mass of fusion protein was 38 ku. It indicated that objective protein was about 12.4 ku. The result showed that E protein was expressed successfully, it was useful to the subsequent E protein research.
基金Supported by the National Technology and Research Project of China(2015BAD12B01-4)
文摘Accurate differentiation of the pathogenic phenotypes of infectious bursal disease viruses(IBDVs) will instruct effective vaccination programs and improve the study of the molecular epidemiology of IBDVs. In this study, an 833 bp hypervariable nucleotide region was identified in VP2 genes of known IBDVs with different virulences through multiple sequence alignment.Moreover, using NEBcutter software analysis, two restriction enzyme sites, SpeⅠ(generating 531 and 302 bp fragments) and StuⅠ(generating 242 and 591 bp fragments) were found presented in very virulent but not attenuated IBDVs. Moreover, the restriction enzyme site SacⅠ(generating 218 and 615 bp fragments) presented in attenuated IBDVs but not very virulent IBDVs. Therefore,a reverse-transcription(RT)-PCR combined with a restriction fragment length polymorphism(RFLP) assay was developed to differentiate attenuated and very virulent IBDVs. The RT-PCR assay was used to confirm 282 IBDV positive samples from 310 suspicious dead chicken samples. The 60 IBDV positive samples were used to evaluate the assay, followed by confirmation via gene sequencing and histopathological examinations of the bursas of Fabricius from chickens infected by these IBDVs. The results showed that 24 viral strains with SpeⅠand StuⅠsites were very virulent, causing severe pathological damage in the bursas of Fabricius, while36 viral strains with the SacⅠsite were attenuated IBDVs, exhibiting only slight pathological damage. The combined RT-PCR and RFLP assay provided a useful approach for differentiating the pathogenic phenotypes of IBDVs.
文摘Chinese isolate of transmissible gastroenteritis virus(TGEV)was propagated and harvested in swine testicle(ST)cells.Two pairs of primers were designed according to the published sequence with Oligo 4.1 and DNasis softwares.The products of RT-PCR were named Sa and Sb,of 2.3kb and 2.1kb respectively.Sa was inserted in EcoR I and Kpn I sites after Sb was cloned in Kpn I and Pst I sites of the same pUC18 plasmid.The recombinant designated pUC-S was verified and analyzed by corresponding restriction endonuclease(RE)and nested PCR on the basis of genetic sites of S gene and physical map of pUC18 plasmid,which was identified as S gene from Chinese isolate of TGEV.
基金Supported by Heilongjiang Natural Science Fund Item (C2004-05)
文摘Garlic virus infection is an important disease which affects garlic production,with the increasing years of planting,harm of virus is serious year by year,which seriously affect yield and quality of garlic.In order to know the garlic virus effectively,the paper reviewed the research situation of several important garlic virus in virus species,origin,distribution,host range,symptom,route of transmission,classification,genome and detection technique and the prevention technology of garlic viruses.At the same ...
基金supported by the Chinese National S&T Plan(2004BA519A55)
文摘The HA1 gene of H3N2 subtype swine influenza virus(SIV)was cloned into the expression plasmid pET-30a,the recombinant plasmid was named pET-HAl.This was transformed into E.coli BL21(DE3),and expressed by induction with IPTG.The expressed HA protein was identified by SDS-PAGE and Western blotting which showed the protein to be 42kDa and was immunoreactive.The purified HA protein was used to establish the indirect ELIS A for detection of the antibodies,specifically against the H3 subtype of SIV.The assay has excellent specificity,sensitivity and reproducibility.When 96 serum samples,randomly collected from the field,were evaluated in parallel by this new ELISA using recombinant HA1 and a routine HI test,the coincidental rate between the two tests was 86.5%.These results show that the recombinant HAl-based ELISA is specific,sensitive and easy to perform for the serological diagnosis of SIV infection.
基金National Natural Science Fundation of China (81471232).
文摘OBJECTIVE How infection of Herpes simplex virus typeⅠ(HSV-1) induces enhancement of autophagy.MEHTODS The wild type HSV-1 strain Kos 1.1 was propagated in Vero cells and purified.SK-N-SH cells seeded in DMEM/F12 were exposed to HSV-1 with 6 h or 12 h and multiplicity of infection(MOI) for 10 or 40 in each experiment.The infectious titers of the HSV-1 samples were determined by plaque assays.MDC staining to test the number of autophagosome within the cell after infection with time and moi was indicated in each experiment.At the molecular level,Western blotting and immunofluorescence analyses were done to study the expression of the proteins related to the cell autophagy.The mRNA transcribed from the gene related to autophagy was quantified by reverse transcription followed by real-time PCR.After intranasal infection of different transgenic mice,immunoflurorence studies were done to detected the expression of Aβ42 and proteins related to autophagy from the brain sections.Morris water maze experiment was performed to test the change of spatial learning and memory between different transgenic mice.RESULTS SK-N-SH cell showed time-and moi-dependent increase of MDC positive staining after HSV-1 infection.Western blotting analysis showed that LC3-Ⅱ was less in mock-infected cells but it was detected after 12 h from 10 to 40 moi HSV-1 infected cells.The level increased in a viral concentration-dependent manner.In agreement with the Western blotting results,direct fluorescence microscopy revealed that the signals of LC3 were consistent with their localization on autophagic compartments.P62,another protein related to autophagoysome formation,also increased with MOI.15 ku fragment of intracellular apolipoproteins E(APOE) protein increased after infection,but at the mRNA level it remained the same.The expression of APP showed less decrease but intracellular Aβ42 increased significantly compared with the mock group.Within the brain,after intranasal infection for 7 d,autophagy related proteins LC3 b and P62 increased as well,at the same time Aβ42 was found co-localized with LC3 b within the cell.Behavior test revealed that 17-month-old APOE4 mice had pool spatial learning and memory after infection compared with other groups.CONCLUSION HSV-1 induces an autophagic response and accelerates the fragmentation of APOE protein.
文摘Objective:It intended to examine whether there is BDV infection in the human tumor tissues of central nervous system in China and investigate the correlation between BDV infection and tumors of central nervous system.Methods:Nested reverse transcriptase polymerase chain reaction(nRT-PCR)and fluorescence quantitative polymerase chain reaction(FQ-PCR)was used to detect the BDV p24 fragments in 60 samples of human tumor tissues of central nervous system and 14 normal brain tissues.Results:The study indicated the positive rate of the BDV p24 fragment in human tumor tissues of the central nervous system(6.67%)was higher than that in normal brain tissues(0),but no statistical significance(P>0.05).Conclusion:It suggests that the BDV infection is present in the human tumor tissues of central nervous system in China, while the sample size wasn't large enough and we could not certify the possible correlation between BDV infection and cenfral nervous system tumors.
文摘We present a rare challenging case of metastatic non-small cell lung cancer with Epstein-Barr virus positivity that was also diagnosed with pulmonary tuberculosis at the same time. Palliative chemotherapy gemcitabine and carboplatin was started after two weeks of anti-tuberculosis treatment with the hopes that this period would be sufficient to keep acid fast bacilli non-viable to minimise risk of tuberculosis re-activation due to chemotherapy induced immunosuppression. She completed four cycles of chemotherapy and six months of anti-tuberculosis treatment with good results and minimal side effects. Two years later, there was disease recurrence in cervical and mediastinal lymph nodes which was treated with local treatment i.e. surgery and palliative radiotherapy. It has been two years since last radiotherapy and overall more than five years since diagnosis with no active disease at present. Given the complexity and rarity of this case, significant multidisciplinary team involvement, including oncologists and radiation oncologists, pulmonologists with special interest in tuberculosis and pathologists was necessary throughout.
文摘Preliminary study has been made to test wether three strains McAb（1B1,5D<sub>6</sub>, 6D<sub>8</sub>）are against the same antigen determinant.Througn ELISA additive and competition expeiments,itproved that these three strains are against different antigen determinant.The result of positiveserum antigen component analysis with 2 strains IBDV McAb showed that sample IBD positiveserum had obvious inhibition against combination of 5D<sub>6</sub> McAb with corresponding antigen.Theresults of substitution of corresponding component in ELISA inhibition experiment and compari-son of non-IBD serum （SPF chicken serum,ND,MD,IA positive serum）proved that IBD anti-serum was the only one showing inhibition against 5D<sub>6</sub> McAb.Comparison with AGP and electro-microscope observation showed that ELISA inhibition experiment was characterised by high-specificity,rapidity and sensitiveness.799 serum samples were tested with ELISA inhibition anddouble immunodiffusion（AGP） experiments.ELISA had gotten 486 positive,with positive rate of60.83%;and AGP 334。
基金Supported by the National Natural Science Foundation of China(31370140 31372438)
文摘Classical swine fever virus(CSFV) is the causative agent of classical swine fever, a highly contagious disease of pigs. But there is little information on the recombination in natural populations of CSFVs. Therefore, a phylogenetic analysis of 62 fulllength genome CSFV strains, isolated from all over the world, was performed to detect potential recombination events, with the recombinant sequences being analyzed with the SimPlot and RDP programs. The results identified a mosaic virus, Chinese CSFV HCLV(2)(AF091507.1), which is the one naturally emerged recombinant CSFV with two recombination breakpoints at 2 484 and 2 900 bp of the genome alignment. Its two putative parental-like strains were CSFV Shimen(AF092448.2) and CSFV strain C/HVRI(AY805221.1). This work demonstrated that homologous recombination did occur in natural CSFV populations. It had significant implications for understanding the molecular epidemiology of CSFV, and revealed that recombination was an important factor for high genetic diversities of CSFV.
基金supported by Technological Project of Zhejiang Emtry-Exit Inspection and Quarantine Bureau(ZK200611)Technology Innovation Service Platform of Inspection and Quarantine for Safe Frontier (2006C1704)
文摘The study was aimed at establishing an indirect ELISA for epidemiological investigation of hepatitis E viral(HEV) infection in pigs from the major pig-producing regions of Zhejiang Province. The gene fragment covering the immunogenic epitopes of HEV ORF2 was synthesized and expressed in Escherichia coli.Western blot analysis revealed that the purified protein reacted to HEV positive sera,but not to positive sera from some other common viruses that infect pigs.An indirect ELISA system was then developed using truncated HEV ORF2 protein as the coating antigen and had diagnostic accuracy of 91.5% as compared with a diagnostic kit for HEV antibodies.A total of 1 330 serum samples were collected from 46 pig farms in Zhejiang Province from 2005-2008 and tested for sero-prevalence of HEV using the indirect ELISA.The average HEV-positive rate was 55.7%(741/1 330).The positive rate of 2005 and 2006 was 62.7%(175/279) and 61.4%(301/490) respectively,much higher than those of 2007(43.0%,59/137) and 2008(48.6%,206/424).Pigs aged 66-100 days had a statistically higher positive rate(58.2%,110/189) when compared to that of pigs aged 30-65 days(39.7%,73/184) or 101-160 days(44.1%,83/188).Only three herds in the study were HEV antibody-negative,indicating high sero-prevalence of HEV in the pig populations in Zhejiang Province.
基金Supported by the National Natural Science Foundation of China(31372438,31200122)
文摘Porcine reproductive and respiratory syndrome virus(PRRSV)GP4 protein was prokaryotically expressed,and used as an antigen to immunize six-week-old BALB/c female mice.With conventional cell fusion method,an anti-PRRSV GP4 protein monoclonal antibody(Mab)5F12 was successfully prepared.It was identified as IgG2b subclass and had better stability and specificity,which not only responded with recombinant PRRSV GP4 protein,but also with PRRSV.Phage display technique had varieties of applications,in particular,the identification of key antigen epitopes for the development of therapeutic and diagnostic reagents and vaccines.In this study,Mab-5F12 was used as the target for biopanning a 12-mer phage random peptide library.After four rounds of biopanning,two phage-displayed peptides,named P-A and P-G(AKFEVCSPVVLG and GVNQENMLHFSF)were identified that recognized Mab-5F12 specifically.Sequence analysis showed that one or more of the peptides exhibited partial sequence similarity to the native GP4 protein sequence,which corresponded to 69-80 and 84-95 aa segments of the HP-PRRSV GP4 protein.Furthermore,real-time quantitative RT-PCR and indirect immunofluorescence assay indicated consistently the abilities of P-A and P-G to block viral infection in Marc-145 cells and they could function as antiviral agents for PRRSV.
文摘Chikungunya fever(CHIKF)is an arboviral disease that typically consists of an acute illness with fever,skin rash,and incapacitating arthralgia.The causative agent of CHIKF is Chikungunya virus(CHIKV),an alphavirus that is transmitted by the Aedes mosquitoes.Despite the re-emergence of CHIKV as an epidemic threat,there is no approved effective anti-viral treatment currently available for CHIKV.In our preliminary studies,selected small molecule inhibitors of arboviruses related to CHIKV were investigated and this led us to identify compounds with thieno[3,2-b]pyrrole scaffold as hits.Building on the discovery of our best hit compounds,5-carboxylic acid thieno[3,2-b]pyrrole 1 and 5-carboxamide thieno[3,2-b]pyrrole 2,the main aim of this study is to optimize their anti-viral activities by synthesizing analogs of thieno[3,2-b]pyrroles 1 and 2 and examine their activities against CHIKV.In these two parallel optimization studies,we synthesized two series of thieno[3,2-b]pyrroles,namely the 5-carboxylic acids and 5-carboxamides that possessed a variety of substituents at N4,C2,C6 or C5positions of the thieno[3,2-b]pyrrole scaffold.These compounds were then examined for their cytotoxicity effects and anti-viral activities using a luminescence-labelled CHIKV infectious clone.The most potent compound in our studies was found in the 5-carboxamide series.The synthesis,biological activity and structure-activity relationship(SAR)will be presented and discussed in detail.
基金The project supported by Young Scientist Funding from Beijing Natural Science Foundation(7154225)by Innovative Research Team in IMPLAD
文摘Influenza virus infection is a global public health issue.The effectiveness of antiviral agents for influenza has been limited by the emergence of drugresistant virus strains.Therefore,there is an urgent need to identify novel antiviral therapies.Our previous studies have found that Cryptoporus volvatus extract could potently inhibit influenza virus replication in vitro and in vivo.However,the effective component of Cryptoporus volvatus which mediated the antiviral activity hasn′t been identified.Here,we identified a novel anti-influenza molecule,cryptoporic acid E(CAE),from Cryptoporus volvatus.Our results showed that CAE had broad-spectrum anti-influenza activity against 2009 pandemic strain A/Beijing/07/2009(H1N1/09),seasonal strain A/Jiangxi/262/05(H3N2),mouse adapted strains A/WSN/33(H1N1)and A/PR8/34(H1N1).We further investigated the mode of CAE action,and found that CAE directlyattenuated influenza virus infectivity.Time-course-analysis indicated that CAE exerted its inhibition mainly at middle stage of the replication cycle of influenza virus.Subsequently,we confirmed that CAE blocked virus RNA replication and transcription in MDCK cells and CAE repressed influenza virus RNA polymerase activity.In addition,we found that CAE impaired influenza virus infectivity by directly targeting virus particles.Our data suggest that CAE is a major effective component of Cryptoporus volvatus and might be a potential candidate for the development of a new anti-influenza virus therapy.
基金Supported by the National Natural Science Foundation of China (31101417 31101415)+1 种基金Zhejiang Provincial Natural Science Foundation of China (Y3110175 Y3110277)
文摘Citrus tristeza virus （CTV）, the most devastating viral pathogen in citrus, causes tremendous economic losses to citrus industry worldwide. The CTV isolates exhibit variable pathogenicities on their hosts indicating a mixed population of the CTV in nature. Several fragments within the CTV genome have been used for studying the genetic diversity of the CTV, however, the best region for rapid the CTV strain differentiation is still absent at present. In present study, a systemic analysis was carried out to evaluate the best region within the CTV genome for rapid CTV strain differentiation. Results of our study showed that the major coat protein （CP） coding region was the best region for this purpose. Using pair-wise distance frequency distribution plot, a reasonable genetic distance cut-off value was set for the CTV CP gene for the CTV strain differentiation. Using this criterion, eight CTV strains, including seven well characterized and a new strain, were successfully differentiated using 537 CTV isolates reported from 38 countries. The global strain distribution pattern was then determined and discussed. Our results also provided a new insight into the evolution and spreading of the virus, as well as the information for developing proper disease management strategy.
