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Ai-long Huang

Publications and source records attributed to Ai-long Huang.

28 records · Page 2Linked to original sources
PubMed2004

[Construction, expression and antigenicity of bivalent vaccine candidate of human Helicobacter pylori].

AIM: To construct a recombinant vector containing fused gene of heat shock protein A(HspA) and outer membrane protein(OMP) with M(r) 18,000, from human Helicobacter pylori(Hp) and express the fusion protein in E.coli BL21. METHODS: The gene encoding HspA was amplified from Hp chromosome by PCR. After digestion with kpn I and BamH I, the HspA gene was inserted into the prokaryotic expression vector pET32a(+). After recombinant vectors pET32a(+)/HspA and pET32a(+)/Omp (18) were digested with Hind III and BamH I, the pET32a(+)/HspA and 18,000 OMP gene segments were recovered through agarose electrophoresis, and connected by T4 ligase. The recombinant vector pET32a(+)/HspA-Omp(18) was transformed into E.coli BL21(DE3). The antigenicity of recombinant fusion protein was analysed by Western blot. RESULTS: Enzyme digestion analysis and sequencing showed that the fused gene had 891 base pairs. As compared with gene reported in GenBank, there were 1.15% and 1.26% differences in cloned nucleotide sequence and amino acid sequence respectively. SDS-PAGE analysis showed that recombinant vector could be expressed in E.coli BL21. The relative molecule mass (M(r)) of expressed fusion protein was 51x10(3). And soluble expression product accounted for 18.96% of total bacterial protein.After purification via Ni-NTA agarose resin, the purity of recombinant fusion protein was about 95%. The Western blot analysis showed that recombinant fusion protein could be recognized by anti-Hp positive serum and anti-18,000 OMP mAb, suggesting that this protein had good antigenicity. CONCLUSION: The fused gene of HspA and OMP is cloned and expressed successfully, which lays the foundation for development of protein and DNA vaccines and a diagnostic kit of Hp infection.

Bacterial Outer Membrane Proteins↗
PubMed2003

[Potent and specific inhibition of hepatitis B virus antigen expression by RNA interference].

OBJECTIVE: To develop an RNAi approach that specifically targets the core gene sequence of hepatitis B virus by synthesizing short interfering RNA (siRNA) in vivo, and to assess the inhibitory effect of this siRNA on HBV replication. METHODS: The eukaryotic expression plasmid pHBV1.3, which contains 1.3-fold-overlength genome of HBV, were cotransfected into HepG2 cells with either the RNAi plasmid pSIHBV/C or unrelated control plasmid pSI. At 24, 48, 72 hours post transfection (p.t.), the levels of HBsAg and HBeAg in the cell culture medium were determined with Abbott MEIA Kits. The expression of intracellular viral proteins was also determined by immunofluorescence staining. RESULTS: Successfully constructed expressing siRNA vector pSIHBV which targeted the core gene of Hepatitis B virus.The introduction of RNAi plasmid was shown to efficiently and specifically inhibit the synthesis of surface and e antigen of HBV by Abbot MEIA kits, with inhibitory rates at 92%, 85% peaking at 24 hours p.t. Immunofluorescence staining showed that intracellular synthesis of viral antigen was sharply reduced to nearly background levels when the ratio of pSIHBV/C and pHBV1.3 was at 1:20, whereas the control vector did not exhibit any inhibitory effect on the replication and expression of HBV. CONCLUSION: Our results demonstrate that the short interfering RNA targeting HBV core gene exerts robust inhibition on HBV viral replication, suggesting that RNAi-based anti-HBV replication strategy may represent a potentially efficacious approach to the clinical management of HBV infection.

Fluorescent Antibody Technique↗
PubMed2003

[Construction, expression and antigenic study of bivalent vaccine candidate with 26,000 OMP and heat short protein A of human Helicobacter pylori].

OBJECTIVE: To construct a recombinant vector containing gene encoding heat shock protein A (HspA) and outer membrane protein (OMP) with relative molecule mass (Mr) of 13,000 and 26,000 respectively from human Helicobacter pylori (Hp) and be expressed in E. coli BL21, as well as analyse its antigenic for the exploiting vaccine of Hp. METHODS: The target gene encoding heat shock protein A was amplified from Hp chromosome by PCR. And then digested by restricted endonuclease enzyme of kpnI, BamH I simultaneously, and inserted into the prokaryotic expression vector pET32a(+) digested by corresponding restricted endonuclease enzyme. The recombinant vector was used to select and transform for sequence analysis. After pET32a(+)/HspA and pET32a(+)/Omp(26) digested by restricted endonuclease enzyme of Hind III, BamH I simultaneously, the pET32a(+)/HspA and 26,000 OMP were taken out of agarose electrophoresis, and connected by T4 ligase. The recombinant vector pET32a(+)/HspA-Omp(26) was used to select and transform, meanwhile expressed in E. coli BL21(DE3). The antigenic of recombinant fusion protein was analysed by western blotting. RESULTS: Enzyme digestion analysis and sequencing showed that the target genes was found to be 951 base pairs, and had been inserted into recombinant vector, but as compared with gene reported by GenBank, 1.15% of the gene mutation and 1.26% of amino acid residues change in Hp happened respectively. SDS-PAGE analysis showed that recombinant vector could be expressed in E. coli BL21, its relative molecule mass of expressed product was 59 x 10(3), while Mr of protein expressed by pET32a(+) of them was about 20 x 10(3), and soluble expression product accounted for 19.96% of total bacterial protein. After purification with Ni-NTA agarose resin, the purity of recombinant fusion protein was about 95%. The western blot result showed that recombinant fusion protein could be recognized by anti-Hp positive serum and monoclonal antibody of 26,000 OMP, suggesting that this protein had good antigenic. CONCLUSION: The genes coding HspA and OMP with Mr 13,000 and 26,000 respectively are cloned and expressed successfully. The results obtained lay the foundation for research on development of Hp protein and DNA vaccine and a quickly diagnostic kit applying to detection of Hp infection.

Bacterial Outer Membrane Proteins↗
PubMed2003

[Long-term health-related quality of life in chronic hepatitis B patients].

OBJECTIVE: To evaluate their long-term outcome and the efficacy and economic significance of antiviral drugs by investigating the long-term health-related quality of life (HQL) in chronic hepatitis B (CHB) patients. METHODS: The HQL of 101 CHB patients with biopsy-proven 6 to 18 years ago and 105 persons of general population as control was studied with revised SF-36 questionnaire. RESULTS: The HQL in CHB patients was lower than that in general population in physical functioning, role physical, general health, mental health, and specific symptoms (mu > or = 2.10, P<0.05). CONCLUSIONS: The long-term HQL in chronic hepatitis B patients is poor.

Adolescent↗
PubMed2003

[Sequence analysis of cloned duck hepatitis B virus genome from a Chongqing brown duck].

OBJECTIVE: To clone and analyze duck hepatitis B virus genome from Chongqing brown duck. METHODS: Duck hepatitis B virus (DHBV) DNA extracted from a Chongqing brown duck was amplified by PCR and cloned into PGEM-T vector using T-A clone method. The sequence of this DHBV genome was analyzed with some softwares after identified. RESULTS: The duck hepatitis B virus genome from Chongqing brown duck (DHBVcq), which was 3 024 nucleotides long, contained three ORFs whose onset and end nucleotides were in accord with those of HPUGA, encoding P, PreC/C and PreS/S protein respectively. Comparison of this strain with other DHBV reported in GenBank showed that the homology of DHBVcq and M32990 got the highest score of 94.9% at nucleotide level, while DHBVcq and DHBVCG got the least (89.8%). Most of the conserved regulation nucleotides and amino acids sequence found in other DHBV were also identified in DHBVcq. The epsilon region of DHBVcq, which was important for encapsidation of pgRNA and synthesis of minus-strand DNA, differed from that of most other DHBV strains, forming a stem-loop conformation with a three- nucleotides upper stem rather than a common nine-nucleotides one in free status. CONCLUSION: The successful clone and analysis of DHBVcq provide further studies with helpful information.

Animals↗
PubMed2003

[Construction of recombinant eukaryotic expression plasmid containing 1.3-fold-overlength genome of HBV and its expression in HepG2 cells].

OBJECTIVES: To transfer 1.3-fold-overlength genome of HBV expression plasmid into HepG2 cells, and observe the dynamic changes of viral replication as well as expression in the transfected cells. METHODS: 4.1 kb fragment of HBV genome, derived from pGEM-HBV, was cloned into Hind III site of the eukaryotic expression vector pCDNA3.1 to construct the recombinant plasmid pHBV. Then HepG2 hepatoma, cells were transfected with pHBV, using Lipofectamine2000 transfection reagent. After 24, 48, 72 hours, the levels of HBsAg and HBeAg in the supernatant of HepG2 cells were determined with Abbott MEIA Kit. Intracellular viral DNA and RNA were analyzed by Southern and northern blot hybridization. In addition, viral-specific proteins (HBsAg and HBcAg) were assayed by immunofluorescence staining. RESULTS: The expression vector pCDNA3.1 was constructed successfully. The levels of HBsAg were 5.36+-0.25, 13.42+-1.24, 7.52+-0.43, and the values of HBeAg were 9.16+-0.32, 22.75+-1.49, 15.96+-1.03 after 24, 48, 72 hours, respectively. All expected HBV replicative intermediates and specific transcripts were verified by Southern and northern blot analysis. The HBsAg-positive cells peaked after 24 hours, and then dropped slowly. HBsAg positive staining scattered in the cytoplasm, whereas HBcAg lied maily in the cytoplasm apart from nuclears. CONCLUSIONS: This recombinant plasmid, which initiates viral replication efficiently in infected cells, is expected as a novel tool for investigating HBV replication in vitro.

Carcinoma, Hepatocellular↗
PubMed2003

[A new method for amplification and sequence analysis of the full-length of HBV genome].

OBJECTIVES: To develop a new method for amplifying and sequencing the full-length of HBV genome. METHODS: A pair of primers located at the nick region of HBV molecule and a thermostable polymerase with high fidelity and sensitivity were used. After cloning the PCR products into a plasmid, the sequences of HBV genome were analyzed. RESULTS: The full-length of HBV genome were acquired using this method. The sensitivity and fidelity of the new method were also analyzed. The least quantity of initial templates was 10(2) and the artificial mutation rate was 1.2 bp/kb. CONCLUSION: This method can be used in amplification and sequence analysis of the full-length of HBV genome on a large scale.

DNA Primers↗
PubMed2003

[Inhibition of survivin expression in liver cancer cells by shRNA].

OBJECTIVE: To construct the plasmid containing short hairpin RNA (shRNA) of survivin in order to suppress the expression of survivin gene in HepG2 and SMMC-7721. METHODS: Two 20 to 21 bp reverse repeated motifs of survivin target sequence with 4 bp or 8 bp spacer were synthesized respectively and inserted into plasmid pTZU6+1 to generate the plasmid pshRNA-survivin1 and pshRNA-survivin2; plasmid pEGFP-C1-survivin and pshRNA-survivin1 or pshRNA-survivin2 plasmid were cotransfected into liver cancer cell HepG2 and SMMC-7721 to detect effect of GFP expression respectively and analyze the inhibition of survivin gene. RESULTS: The recombinant plasmid pshRNA-survivin1 and pshRNA-survivin2 were successfully constructed. The recombinant plasmids suppress the survivin expression by 80% in HepG2 and SMMC-7721. CONCLUSION: The result showed that the short hairpin RNA of survivin can efficiently suppress it's expression in HepG2 and SMMC-7721.

Gene Expression Regulation, Neoplastic↗