Publications (15)13.58 Total impact
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Article: A monoclonal antibody against PrM/M protein of Japanese encephalitis virus.
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ABSTRACT: Japanese encephalitis virus (JEV) is a major public health threat in the Asia-Pacific region. The pre-membrane (PrM) protein of Japanese encephalitis virus is cleaved during maturation by the cellular protease into the structural protein M and a pr-segment. Here, we describe a procedure to generate monoclonal antibody (MAb) against JEV PrM/M protein and investigate its characteristics. Western blot analysis showed that the MAbs produced in this study were against JEV PrM/M specifically. Indirect immunofluorescence assay demonstrated that they could recognize native PrM/M protein in JEV-infected BHK-21 cells. Preliminary studies identified the epitope of the MAb with a set of synthesized overlapping peptides covering the whole length of PrM protein of JEV. The MAbs reported here may provide valuable tools for the further exploration of biological properties and functions of PrM/M protein and may also be developed for potential clinical applications.Hybridoma (2005) 10/2011; 30(5):451-6. · 0.42 Impact Factor -
Article: Comprehensive mapping of West Nile virus (WNV)- and Japanese encephalitis virus serocomplex-specific linear B-cell epitopes from WNV non-structural protein 1.
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ABSTRACT: West Nile virus (WNV) non-structural protein 1 (NS1) elicits protective immune responses during infection of animals. WNV NS1-specific antibody responses can provide the basis for serological diagnostic reagents, so the antigenic sites in NS1 that are targeted by host immune responses need to be identified and the conservation of these sites among the Japanese encephalitis virus (JEV) serocomplex members also needs to be defined. The present study describes the mapping of linear B-cell epitopes in WNV NS1. We screened eight NS1-specific mAbs and antisera (polyclonal antibodies; pAbs) from mice immunized with recombinant NS1 for reactivity against 35 partially overlapping peptides covering the entire WNV NS1. The screen using mAbs identified four WNV-specific (including Kunjin virus) epitopes, located at aa 21-36, 101-116, 191-206 and 261-276 in WNV NS1. However, using pAbs, only three WNV-specific epitopes were identified, located at positions 101-116, 191-206 and 231-246. Two of these epitopes (aa 21-36 and 261-276) had different reactivity with mAbs and pAbs. The knowledge and reagents generated in this study have potential applications in differential diagnostics and epitope-based marker vaccine development for WNV and viruses of the JEV serocomplex.Journal of General Virology 09/2011; 93(Pt 1):50-60. · 3.36 Impact Factor -
Article: Identification of a conserved JEV serocomplex B-cell epitope by screening a phage-display peptide library with a mAb generated against West Nile virus capsid protein.
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ABSTRACT: The West Nile virus (WNV) capsid (C) protein is one of the three viral structural proteins, encapsidates the viral RNA to form the nucleocapsid, and is necessary for nuclear and nucleolar localization. The antigenic sites on C protein that are targeted by humoral immune responses have not been studied thoroughly, and well-defined B-cell epitopes on the WNV C protein have not been reported. In this study, we generated a WNV C protein-specific monoclonal antibody (mAb) and defined the linear epitope recognized by the mAb by screening a 12-mer peptide library using phage-display technology. The mAb, designated as 6D3, recognized the phages displaying a consensus motif consisting of the amino acid sequence KKPGGPG, which is identical to an amino acid sequence present in WNV C protein. Further fine mapping was conducted using truncated peptides expressed as MBP-fusion proteins. We found that the KKPGGPG motif is the minimal determinant of the linear epitope recognized by the mAb 6D3. Western blot (WB) analysis demonstrated that the KKPGGPG epitope could be recognized by antibodies contained in WNV- and Japanese encephalitis virus (JEV)-positive equine serum, but was not recognized by Dengue virus 1-4 (DENV1-4)-positive mice serum. Furthermore, we found that the epitope recognized by 6D3 is highly conserved among the JEV serocomplex of the Family Flaviviridae. The KKPGGPG epitope is a JEV serocomplex-specific linear B-cell epitope recognized by the 6D3 mAb generated in this study. The 6D3 mAb may serve as a novel reagent in development of diagnostic tests for JEV serocomplex infection. Further, the identification of the B-cell epitope that is highly conserved among the JEV serocomplex may support the rationale design of vaccines against viruses of the JEV serocomplex.Virology Journal 03/2011; 8:100. · 2.34 Impact Factor -
Article: Identification of two linear B-cell epitopes from West Nile virus NS1 by screening a phage-displayed random peptide library.
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ABSTRACT: The West Nile virus (WNV) nonstructural protein 1 (NS1) is an important antigenic protein that elicits protective antibody responses in animals and can be used for the serological diagnosis of WNV infection. Although previous work has demonstrated the vital role of WNV NS1-specific antibody responses, the specific epitopes in the NS1 have not been identified. The present study describes the identification of two linear B-cell epitopes in WNV NS1 through screening a phage-displayed random 12-mer peptide library with two monoclonal antibodies (mAbs) 3C7 and 4D1 that directed against the NS1. The mAbs 3C7 and 4D1 recognized phages displaying peptides with the consensus motifs LTATTEK and VVDGPETKEC, respectively. Exact sequences of both motifs were found in the NS1 ((895)LTATTEK(901) and (925)VVDGPETKEC(934)). Further identification of the displayed B cell epitopes were conducted using a set of truncated peptides expressed as MBP fusion proteins. The data indicated that (896)TATTEK(901) and (925)VVDGPETKEC(934) are minimal determinants of the linear B cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. Antibodies present in the serum of WNV-positive horses recognized the minimal linear epitopes in Western blot analysis, indicating that the two peptides are antigenic in horses during infection. Furthermore, we found that the epitope recognized by 3C7 is conserved only among WNV strains, whereas the epitope recognized by 4D1 is a common motif shared among WNV and other members of Japanese encephalitis virus (JEV) serocomplex. We identified TATTEK and VVDGPETKEC as NS1-specific linear B-cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. The knowledge and reagents generated in this study may have potential applications in differential diagnosis and the development of epitope-based marker vaccines against WNV and other viruses of JEV serocomplex.BMC Microbiology 01/2011; 11:160. · 3.04 Impact Factor -
Article: Identification and characterization of a virus-specific continuous B-cell epitope on the PrM/M protein of Japanese Encephalitis Virus: potential application in the detection of antibodies to distinguish Japanese Encephalitis Virus infection from West Nile Virus and Dengue Virus infections.
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ABSTRACT: Differential diagnose of Japanese encephalitis virus (JEV) infection from other flavivirus especially West Nile virus (WNV) and Dengue virus (DV) infection was greatly hindered for the serological cross-reactive. Virus specific epitopes could benefit for developing JEV specific antibodies detection methods. To identify the JEV specific epitopes, we fully mapped and characterized the continuous B-cell epitope of the PrM/M protein of JEV. To map the epitopes on the PrM/M protein, we designed a set of 20 partially overlapping fragments spanning the whole PrM, fused them with GST, and expressed them in an expression vector. Linear epitope M14 (105VNKKEAWLDSTKATRY120) was detected by enzyme-linked immunosorbent assay (ELISA). By removing amino acid residues individually from the carboxy and amino terminal of peptide M14, we confirmed that the minimal unit of the linear epitope of PrM/M was M14-13 (108KEAWLDSTKAT118). This epitope was highly conserved across different JEV strains. Moreover, this epitope did not cross-react with WNV-positive and DENV-positive sera. Epitope M14-13 was a JEV specific lineal B-cell epitpe. The results may provide a useful basis for the development of epitope-based virus specific diagnostic clinical techniques.Virology Journal 01/2010; 7:249. · 2.34 Impact Factor -
Article: [Study on the DNA immunogenicity of fusion and attachment glycoproteins of Nipah virus].
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ABSTRACT: The two mammalian codon optimized genes, F and G genes of Nipah virus, were generated by assembly PCR, and inserted into mammalian expression vector pCAGGS under chicken beta-actin promoter to construct pCAGG-NiV-F and pCAGG-NiV-G. Syncytium formation was induced in BHK cells by plasmid pCAGG-NiV-F and pCAGG-NiV-G transfection, which indicate recombination proteins F and G were expressed in BHK cell and possessed good biologic activity. Six-week-old female BALB/c mice were intramuscularly primed with 100 microg pCAGG-NiV-F, pCAGG-NiV-G or pCAGG-NiV-F+ pCAGG-NiV-G respectively, and boosted with same dose after 4 weeks. The sera were collected at 3 weeks post second boost. The serum IgG against Nipah virus F and G proteins was detected by indirect ELISA using recombinant Baculovirus expressed Nipah F and G glycoproteins. The results showed that specific antibodies possessed good sensitivity and specificity. Furthermore, the G and F proteins' specific antibodies could neutralize the infectivity of VSVdeltaG* F/G (the NiV F and G envelope glycoproteins psudotyped recombinant vesicular stomatitis virus expressing green fluorescence protein). And, pCAGG-NiV-G also induced higher titer of neutralizing antibody response than pCAGG-NiV-F did. The result indicates that DAN immunization is an efficient vaccine strategy against Nipah virus.Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] 02/2008; 24(1):47-52. -
Article: [Expression of recombinant bovine beta-interferon by baculovirus system and evaluation of its bioactivity].
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ABSTRACT: In this paper, a recombinant baculovirus containing the ORF of bovine interferon-beta (BoIFN-beta) gene, rBac-BoIFN-beta, was generated to express recombinant BoIFN-beta (rBoIFN-beta) in sf9 insect cells. The expression of rBoIFN-beta in rBac-BoIFN-beta infecting sf9 cells and its supernatants was confirmed by indirect immunofluorescence assay and Western blot. The antiviral activity of rBoIFN-beta in the supernatant can reach 10(6.0) AU/mL evaluated by the antiviral assay with VSV * GFP that expressed green fluorescence protein, and rBoIFN-beta could stimulate the expression of luciferase reporter gene controlled by chicken Mx promoter. All the results showed that rBac-BoIFN-beta constructed here could express high level recombinant BoIFN-beta in secreted form that had the bioactivity of natural type I IFN.ACTA MICROBIOLOGICA SINICA 01/2008; 47(6):992-6. -
Article: [Study on DNA immune of envelope protein gene of Rift Valley Fever Virus].
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ABSTRACT: DNA vaccines have successfully induced effective antibody and cellular immune response to many viral pathogens. The antibody response of DNA immunization induction in mouse model with envelope glycoproteins of Rift Valley Fever Virus (RVFV), G (N + C), GN and GC was investigated. For this purpose, three codon G (N + C), GN and GC gene were insert into mammalian expression vector pCAGGS under chicken beta-actin promoter to construct pCAGG-RVFV-GN, pCAGG-RVFV-GC and pCAGG-RVFV-G (N + C). The expression of recommbinant GN or / and GC protein in BHK cells transfected with pCAGG-RVFV-GC or pCAGG-RVFV-G (N + C) DNA were confirmed by immunoprecipitation. Six-week-old female BALB/c mice were intramuscularly primed with 100 (g pCAGG-RVFV-GN + pCAGG-RVFV-GC + pCAGG-RVFV-G (N + C), and boosted with same dose after 4 weeks. The serums were collected at 3 weeks post final boost. The serum IgG against Rift Valley Fever Virus G (N + C) protein were detect by indirect ELISA using recombinant Baculovirus expressed Rift Valley Fever Virus GN and GC glycoprotein. The mixture of pCAGG-RVFV-GN, pCAGG-RVFV-GC and pCAGG-RVFV-G (N + C) elicited much strong IgG response. For serum neutralization antibody assay, a recombinant Vesicular Stomatitis Virus pseudotype, in which the VSV envelope protein G gene was replaced with the green fluorescent protein gene (VSVdeltaG x G, Whitt M A) and complemented with Rift Valley Fever Virus G (N + C) glycoprotein expressed in transient (VSVdeltaG x RVFV-G), was use to replace the authentic Rift Valley Fever Virus. The mixture of pCAGG-RVFV-GN, pCAGG-RVFV-GC and pCAGG-RVFV-G (N + C) also induced high titer of neutralization antibody response. These result indicates that DNA immunization is an efficient vaccine strategy against Rift Valley Fever Virus.ACTA MICROBIOLOGICA SINICA 09/2007; 47(4):677-81. -
Article: [Expression of recombinant spike protein of SARS-coronavirus in vaccinia virus and analysis of its immunogenicity].
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ABSTRACT: A recombinant vaccinia virus (rWR-SARS-S)expressing spike protein of severe acute respiratory syndrome coronavirus was constructed. The expression of full length recombinant SARS spike protein (rSS) in HeLa cells possessing specific reaction ability to chicken anti-sera was confirmed by SDS-PAGE and Western-blot (190 kD). HeLa cells infected with rWR-SARS-S also showed high sensitivity in detecting specific serum antibody by indirect immunofluoresence assay (IFA). The results above indicated that the availability of such a faithful model system offers particular advantages for the study of SARS in that it reduces the need for direct manipulation of an exotic pathogen. In the absence of infectious SARS, we may safely carry out detailed biochemical and genetic manipulations to investigate features of viral replication and gene function, as well as explore new avenue for vaccine development.Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] 08/2007; 23(4):287-91. -
Article: [Expression of bovine interferon gamma in recombinant baculovirus and determination of its antiviral activity].
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ABSTRACT: The full-length bovine interferon gamma (BoIFN-gamma) cDNA, including the secretion signal peptide coding region was recloned into baculovirus honor vectors pFastBac 1 of Bac-To-Bac system. These recombinant plasmids, pFastBac 1-BoIFN-gamma, were transformed into DH(10Bac) host bacteria to get recombinant shuttle plasmids, rBacmid-BoIFN-gamma. Recombinant baculovirus, rBac-BoIFN-gamma, was generated for expressing BoIFN-gamma, by transfecting recombinant Bacmid-BoIFN-gamma with Cellfectin Reagen into sf9 insect cells. BoIFN-gamma efficiently expressed by recombinant baculovirus in sf9 cells was testified by indirect immunofluorescence assay and indirect ELISA with monoclonal antibody against Bovine interferon-gamma. Furthermore, VSV * GFP, recombinant Vesicular Stomatitis Virus expressing green fluorescence protein and MDBK were used to determine the anti-viral activity of rBoIFN-gamma. The result shows rBoIFN-gamma could inhibit the replication of the VSV * GFP in MDBK cells and the antiviral activity of supernatant was 2 x 10(5) IU/mL. The antiviral activity of rBoIFN-gamma could be blocked by anti-BoIFN-gamma mouse serum. The results demonstrated that the recombinant baculovirus could express BoIFN-gamma efficiently and rBoIFN-gamma had high antiviral activity.ACTA MICROBIOLOGICA SINICA 07/2007; 47(3):503-7. -
Article: [Expression of porcine gamma-interferon in recombinant baculovirus and determination of its antiviral activity].
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ABSTRACT: The full-length porcine interferon gamma(PoIFN-gamma) cDNA, including the secretion signal peptide coding region was recloned into honor plasmid pFastBac 1 of Bac-To-Bac Baculovirus Expression System. These recombinant plasmids, pFastBac -PoIFN-gamma, were transformed into DH(10Bac) host bacteria to get recombinant shuttle plasmids, rBacmid-PoIFN-gamma. Recombinant baculovirus, rBac-PoIFN-gamma, was generated for expressing PoIFN-gamma, by transfecting rBacmid-PoIFN-gamma with Cellfectin Reagent into sf9 insect cells. The expression of PoIFN-gamma in insect cells was confirmed by Western Blot, indirect immunofluorescence assay and indirect ELISA. The antiviral activity assay shows that PoIFN-gamma expressed by the rBac-PoIFN-gamma can efficiently inhibit the replication of the recombinant Vesicular Stomatitis Virus expressing green fluorescence protein in PK-15 cells. The antiviral activity of PoIFN-gamma can be specifically blocked by anti-PoIFN-gamma mouse serum. The antiviral titer of culture supernatant of insect cells infected by rBac-PoIFN-gamma is 2 x 10(4) IU/mL. The results demonstrat that the rBac-PoIFN-gamma can express rPoIFN-gamma efficiently and rPoIFN-gamma has high antiviral activity.Sheng wu gong cheng xue bao = Chinese journal of biotechnology 06/2007; 23(3):386-91. -
Article: [Generation of recombinant vaccinia virus expressing attachment glycoprotein of Nipah virus].
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ABSTRACT: The mammalian condon optimized G gene was synthesized by over-lapping PCR and used to generate recombinant vaccinia virus, rWR-NiV-G. The expression of Nipah virus G protein in rWR-NiV-G infected HeLa cells was confirmed by western-blot with NiV G protein specific mouse antiserum generated by DNA immunization.The recombinant G protein showed sensitive and specific antigenic reaction to rabbit serum anti-Nipah virus in indirect florescence. Syncytium formation was induced in BHK cells by rWR-NiV-G infection following NiV F protein expressing plasmid pCAGG-NiV-F transfection. Immunization with rWR-NiV-G elicited G protein specific antibody responses in mice. The prokaryotic expressing G protein fragment showed sensitive and specific antigenic reaction to NiV G protein specific antibody from rWR-NiV-G immunized mice serum in indirect ELISA. Furthermore, the G protein specific antibodies could neutralize the infectivity of the recombinant Vesicular Stomatitis Virus pseudotype VSVAG * F/G, in which the VSV envelope protein G gene was replaced with the green fluorescent protein gene (VSVAG * G, Whitt MA) and complemented with Nipah virus F and G glycoprotein expressed in transient (VSVAG * F/G).The results here demonstrated the G protein expressed by rWR-NiV-G keeps native immunogenicity and biological activity. The recombinant virus could be promising vaccine strategy for the prevention of Nipah virus.ACTA MICROBIOLOGICA SINICA 09/2006; 46(4):644-8. -
Article: [Rescue of a recombinant Newcastle disease virus expressing the green fluorescent protein].
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ABSTRACT: A recombinant Newcastle disease virus (NDV) expressing the green fluorescent protein (GFP) was generated by applying reverse genetics techniques. The GFP open reading frame flanked by NDV transcription start and stop sequences was inserted between the phosphoprotein (P) and matrix protein (M) in a full-length cDNA clone of NDV Lasota vaccine strain. This plasmid transcribing antigenome RNA was cotransfected with helper plasmids expressing viral nucleoprotein, phosphoprotein and large protein into cells stably expressing T7 RNA polymerase. The rescued virus was first propagated in 10-day-old embryonated eggs and the allantoic fluid was used to infect primary chicken embryo fibroblasts (CEF) cells. The appearance of GFP in live infected cells confirmed further the recovery of a recombinant NDV (rNDV-GFP) expressing this reporter gene. Nine successive passages in embryonated chicken eggs were performed. Allantoic fluid samples were then titrated by a microtiter plate HA test. HA positive ailantoic fluid were used for further egg passages. All the allantoic fluid samples were titrated by end point dilutions and infected cells were examined for the presence of GFP expression. To analyze virus growth, 10-day-old embryonated SPF chicken eggs were inoculated with 1 x 10(4) EID50 rNDV or rNDV-GFP. At 24,48,72 and 96 h p.i. the allantoic fluid of inoculated eggs containing live embryos was harvested and clarified by centrifugation. Supernatants were used for titration of EID50 in 10-day-old embryonated SPF chicken eggs. rNDV and rNDV-GFP grew to similar titers (10(9) EID50/mL). In order to test the virulence of rNDV-GFP, infectious allantoic fluid of rNDV-GFP were inoculated into embryonated SPF chicken eggs at 1 x 10(6) EID50. No dead embryonated egg was found within 96 hours. The replication kinetics and pathogenicity in SPF embryonated eggs of rNDV-GFP did not differ significantly from that of the parent virus. LaSota is a widely used NDV live vaccine strain. The reverse genetic system established for this LaSota vaccine strain provided a useful platform for development of novel live viral vector vaccines in future.ACTA MICROBIOLOGICA SINICA 09/2006; 46(4):547-51. -
Article: [Study of fusion protein and attachment glycoprotein of Nipah virus expressed in recombinant baculovirus].
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ABSTRACT: In this study, Recombinant baculoviruses rBac-NF and rBac-NG were generated for expressing F and G proteins Nipah virus (NiV) . The expression of recommbinant G (rNG) and F (rNF) protein in rBac-NF and rBac-NG infected cells were confirmed by western-blot. Both rNG and rNF showed sensitive and specific antigenic reaction to rabbit serum anti-Nipah virus in indirect immunofluorescence detection and indirect ELISA. Immunization with rBac-NF and rBac-NG infected insect cells elicited G ad F protein specific antibody responses in mice. Furthermore, the G ad F specific antibodies could neutralize the infectivity of the VSVdeltaG* F/G, the NiV F and G envelope glycoproteins psudotyped recombinant Vesicular Stomatitis Virus expressing green fluorescence protein. The results demonstrated F and G protein expressed by the recombinant baculoviruses could be safe economic diagnostic antigens for the surveillance and monitoring of NiV and promising subunit vaccines for the prevention of NiV.Sheng wu gong cheng xue bao = Chinese journal of biotechnology 06/2006; 22(3):418-24. -
Article: Identification and antigenic epitope mapping of immunodominant region amino residues 510 to 672 on the spike protein of the severe acute respiratory syndrome coronavirus.
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ABSTRACT: The severe acute respiratory syndrome (SARS) is a newly emerging human infectious disease caused by the severe acute respiratory syndrome coronavirus (SARS-CoV). The spike (S) protein of SARS-CoV is a major virion structural protein. It plays an important role in the interaction with receptors and neutralizing antibodies. In this study, the S1 domain of the spike protein and three truncated fragments were expressed by fusion with GST in a pGEX-6p-1 vector. Western blot results demonstrated that the 510-672 fragment of the S1 domain is a linear epitope dominant region. To map the antigenic epitope of this linear epitope dominant region, a set of 16 partially overlapping fragments spanning the fragment were fused with GST and expressed. Four antigenic epitopes S1C3 (539-559), S1C4 (548-567), S1C7/8 (583-606), and S1C10/11 (607-630) were identified. Immunization of mice with each of the four antigenic epitope-fused proteins revealed that all four proteins could elicit spike protein specific antisera. All of them were able to bind to the surface domain of the whole spike protein expressed by recombinant baculovirus in insect cells. Identification of antigenic epitopes of the spike protein of SARS-CoV may provide the basis for the development of immunity-based prophylactic, therapeutic, and diagnostic clinical techniques for the severe acute respiratory syndrome.DNA and Cell Biology 09/2005; 24(8):503-9. · 2.07 Impact Factor
Top co-authors
Top Journals
Institutions
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2006–2011
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Harbin Veterinary Research Institute
Harbin, Heilongjiang Sheng, China
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2006–2008
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Nanjing Agricultural University
Nanjing, Jiangsu Sheng, China
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