BACKGROUND: The pathogenesis of severe hepatitis B remains unknown. Reports have indicated that hepatitis B virus (HBV) mutations are important factors in the pathogenesis of this disease. This study was to investigat...BACKGROUND: The pathogenesis of severe hepatitis B remains unknown. Reports have indicated that hepatitis B virus (HBV) mutations are important factors in the pathogenesis of this disease. This study was to investigate the genetic heterogeneity of HBV strains from serum samples of patients with fulminant hepatitis B. METHODS: Full-length HBV genomes from 4 patients with severe hepatitis B were cloned and sequenced to observe mutations in every open reading-frame ( ORF). Serum samples of another 25 patients with severe hepatitis B, 30 patients with chronic hepatitis B, and 25 HBV carriers were collected for sequencing and comparison of mutations in preS2, preC and core promoter regions. RESULTS: Of 4 HBV full-length genome sequences, 3 had a G to A mutation at nucleotide A1896 in the preC region and 1 had double mutations of T1762-A1764 in the core promoter region. The 4 sequences showed mutations in the known B or T cell epitopes of the preS2 and C regions. For the other 3 groups, more mutations were seen in the preS2 region in the HBV isolates from the patients with severe hepatitis B than those from the patients with chronic hepatitis B and HBV carriers (P <0.01). There was a significant difference of mutations in the T cell epitope region of preS2 between the patients with severe hepatitis B and those with chronic hepatitis B or HBV carriers (P <0.01). In the preC and core promoter regions, the mutation frequencies of T1653 and C1753 were 48.0% and 24.0% respectively in the patients with severe hepatitis B, but none of these mutations were observed in the patients with chronic hepatitis B group or HBV carriers (P <0.01). The mutation frequency of T1762-A1764 was 76.0% in the patients with severe hepatitis B, 40.0% in the patients with chronic hepatitis B (P <0. 01) , and 16. 0% in the HBV carriers ( P < 0. 01). There was a significant difference in A1896 mutation between the patients with severe hepatitis B and the patients with chronic hepatitis B (P < 0. 05 ) or the HBV carriers (P<0.05). CONCLUSION: Our obs展开更多
Objectives To construct a hepatoma directed gene delivery system which could transfer preS2 antisense RNA to liver cancer cells specifically, and to explore a new therapeutic strategy for hepatocellular carcinoma by ...Objectives To construct a hepatoma directed gene delivery system which could transfer preS2 antisense RNA to liver cancer cells specifically, and to explore a new therapeutic strategy for hepatocellular carcinoma by blocking hepatitis B virus (HBV) with antisense RNA targeting hepatocellular carcinoma. Methods GE7 and HA20 were synthesized and mixed with pEBAF-as-preS2, a hepatocarcinoma specific HBV antisense expression vector, to construct a novel HBV antisense RNA delivery system named AFP-enhancing 4-element complex. Nude mice bearing hepatocelluar carcinoma cells HepG2.2.15 were injected with AFP-enhancing 4-element complex via a tail vein. Total RNA from tissues was extracted, and reversal transcription-ploymerase chain reaction (RT-PCR) was used to detect the expression of preS2. Different doses of AFP-enhancing 4-element complex was injected into nude mice at different time points, and tumor diameter was measured.Results AFP-enhancing 4-element complex was constructed successfully. RT-PCR showed preS2 antisense RNA delivered by AFP-enhancing 4-element complex only expressed in liver tumor HepG2.2.15 cells of the mice. After the treatment of AFP-enhancing 4-element complex with dose of 0.2 μg per mouse (once a week for 4 weeks), the mean tumor diameter of nude mice was significantly shorter than that of the control groups (0.995±0.35 cm vs 2.125±0.25 cm, P<0.01). Conclusions An HBV antisense RNA gene delivery system targeting hepatocellular carcinoma, AFP-enhancing 4-element complex, was constructed successfully. PreS2 antisense RNA expressed specifically in hepatocelluar carcinoma cells significantly inhibits tumor growth of mice bearing hepatocarcinoma HepG2.2.15 and may have therapeutic potential in HBV related hepatocarcinoma.展开更多
The DNA fragments coding for preS2(120 146) and preS1(21 47) amplified by PCR were fused to both 5′ and 3′ ends of S gene at the position of amino acid 223. The fusion gene was placed downstream of the promoter P7.5...The DNA fragments coding for preS2(120 146) and preS1(21 47) amplified by PCR were fused to both 5′ and 3′ ends of S gene at the position of amino acid 223. The fusion gene was placed downstream of the promoter P7.5 of the universal vaccinia viral vector pGJP 5 and the recombinant vaccinia virus vS2SS1 was then selected by \%in vivo\% homogeneous recombination. Fusion protein S2SS1 could be expressed in the mammalian cells infected with vS2SS1. The investigation of expression, secretion, antigenicity and particle assembly of the S2SS1 protein demonstrated that S2SS1 protein could be assembled into particles which presented preS1, preS2 and S antigenicity and be efficiently secreted from the cells. It also showed that the level of its expression and secretion approached to that of the S protein expressed by the recombinant vaccinia virus.展开更多
Despite the long availability of a traditional prophylactic vaccine containing the HBV surface antigen(HBsA g) and aluminum adjuvant, nearly 10% of the population remains unable to generate an effective immune respons...Despite the long availability of a traditional prophylactic vaccine containing the HBV surface antigen(HBsA g) and aluminum adjuvant, nearly 10% of the population remains unable to generate an effective immune response. Previous studies have indicated that hepatitis B virus(HBV) PreS 2-S is abundant in T/B cell epitopes, which induces a stronger immune response than HBsA g, particularly in terms of cytotoxic T lymphocyte(CTL) reaction. In the current study, the HBV PreS 2-S gene encoding an extra26 amino acids(PreS 2 C-terminus) located at the N-terminus of HBsA g was cloned into the pV CH1300 expression vector. Pre S2-S expressed in the methylotrophic yeast, Hansenula polymorpha, was produced at a yield of up to 250 mg/L. Subsequent purification steps involved hydrophobic adsorption to colloidal silica, ion-exchange chromatography and density ultracentrifugation. The final product was obtained with a total yield of ~15% and purity of ~99%. In keeping with previous studies, ~22 nm viruslike particles were detected using electron microscopy. The generated PreS 2-S antigen will be further studied for efficacy and safty in animals.展开更多
AIM:To investigate the inhibitory effect of hepatitis B virus (HBV) preS2 antibody (preS2Ab) against HBV in-fection and HBV-associated hepatic carcinogenesis.METHODS:An adenoviral vector carrying the full-length light...AIM:To investigate the inhibitory effect of hepatitis B virus (HBV) preS2 antibody (preS2Ab) against HBV in-fection and HBV-associated hepatic carcinogenesis.METHODS:An adenoviral vector carrying the full-length light and heavy chains of the HBV preS2Ab gene,Ad315-preS2Ab,was constructed.Enzyme linked immunosorbent assay (ELISA) and Western blotting analyses were used to determine the preS2Ab expres-sion levels in vitro.Immunofluorescent techniques were used to examine the binding affinity between the expressed HBV preS2Ab and HBV-positive liver cells.ELISAs were also used to determine hepatitis B surface antigen (HBsAg) levels to assess the inhibitory effect of the preS2Ab against HBV infection in L02 cells.The inhibitory effect of preS2Ab against hepatic carcinogen-esis was studied with diethylnitrosamine (DEN)-induced hepatocellular carcinomas (HCCs) in HBV transgenic mice.RESULTS:The expression of HBV preS2Ab increased with increases in the multiplicity of infection (MOI) of Ad315-preS2Ab in L02 cells,with 350.87 ± 17.37 μg/L of preS2Ab when the MOI was 100 plaque forming units (pfu)/cell.The expressed preS2Abs could recog-nize liver cells from HBV transgenic mice.ELISA results showed that L02 cells expressing preS2Ab produced less HBsAg after treatment with the serum of HBV pa-tients than parental L02 cells expressing no preS2Ab.HBV transgenic mice treated with Ad315-preS2Ab had fewer and smaller cancerous nodes after induction with DEN than mice treated with a blank Ad315 vec-tor or untreated mice.Additionally,the administration of Ad315-preS2Ab could alleviate hepatic cirrhosis and decrease the serum levels of alanine transaminase and aspartate transaminase.CONCLUSION:Adenovirus-mediated HBV preS2Ab expression could inhibit HBV infection in L02 cells,and then inhibit DEN-induced hepatocellular carcinogenesis and protect hepatic function in HBV transgenic mice.展开更多
基金This study was supported a grant from Health Bureau of Zhejiang Province, China ( No: 20020302).
文摘BACKGROUND: The pathogenesis of severe hepatitis B remains unknown. Reports have indicated that hepatitis B virus (HBV) mutations are important factors in the pathogenesis of this disease. This study was to investigate the genetic heterogeneity of HBV strains from serum samples of patients with fulminant hepatitis B. METHODS: Full-length HBV genomes from 4 patients with severe hepatitis B were cloned and sequenced to observe mutations in every open reading-frame ( ORF). Serum samples of another 25 patients with severe hepatitis B, 30 patients with chronic hepatitis B, and 25 HBV carriers were collected for sequencing and comparison of mutations in preS2, preC and core promoter regions. RESULTS: Of 4 HBV full-length genome sequences, 3 had a G to A mutation at nucleotide A1896 in the preC region and 1 had double mutations of T1762-A1764 in the core promoter region. The 4 sequences showed mutations in the known B or T cell epitopes of the preS2 and C regions. For the other 3 groups, more mutations were seen in the preS2 region in the HBV isolates from the patients with severe hepatitis B than those from the patients with chronic hepatitis B and HBV carriers (P <0.01). There was a significant difference of mutations in the T cell epitope region of preS2 between the patients with severe hepatitis B and those with chronic hepatitis B or HBV carriers (P <0.01). In the preC and core promoter regions, the mutation frequencies of T1653 and C1753 were 48.0% and 24.0% respectively in the patients with severe hepatitis B, but none of these mutations were observed in the patients with chronic hepatitis B group or HBV carriers (P <0.01). The mutation frequency of T1762-A1764 was 76.0% in the patients with severe hepatitis B, 40.0% in the patients with chronic hepatitis B (P <0. 01) , and 16. 0% in the HBV carriers ( P < 0. 01). There was a significant difference in A1896 mutation between the patients with severe hepatitis B and the patients with chronic hepatitis B (P < 0. 05 ) or the HBV carriers (P<0.05). CONCLUSION: Our obs
基金ThisstudywassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina (No 39970 333)
文摘Objectives To construct a hepatoma directed gene delivery system which could transfer preS2 antisense RNA to liver cancer cells specifically, and to explore a new therapeutic strategy for hepatocellular carcinoma by blocking hepatitis B virus (HBV) with antisense RNA targeting hepatocellular carcinoma. Methods GE7 and HA20 were synthesized and mixed with pEBAF-as-preS2, a hepatocarcinoma specific HBV antisense expression vector, to construct a novel HBV antisense RNA delivery system named AFP-enhancing 4-element complex. Nude mice bearing hepatocelluar carcinoma cells HepG2.2.15 were injected with AFP-enhancing 4-element complex via a tail vein. Total RNA from tissues was extracted, and reversal transcription-ploymerase chain reaction (RT-PCR) was used to detect the expression of preS2. Different doses of AFP-enhancing 4-element complex was injected into nude mice at different time points, and tumor diameter was measured.Results AFP-enhancing 4-element complex was constructed successfully. RT-PCR showed preS2 antisense RNA delivered by AFP-enhancing 4-element complex only expressed in liver tumor HepG2.2.15 cells of the mice. After the treatment of AFP-enhancing 4-element complex with dose of 0.2 μg per mouse (once a week for 4 weeks), the mean tumor diameter of nude mice was significantly shorter than that of the control groups (0.995±0.35 cm vs 2.125±0.25 cm, P<0.01). Conclusions An HBV antisense RNA gene delivery system targeting hepatocellular carcinoma, AFP-enhancing 4-element complex, was constructed successfully. PreS2 antisense RNA expressed specifically in hepatocelluar carcinoma cells significantly inhibits tumor growth of mice bearing hepatocarcinoma HepG2.2.15 and may have therapeutic potential in HBV related hepatocarcinoma.
文摘The DNA fragments coding for preS2(120 146) and preS1(21 47) amplified by PCR were fused to both 5′ and 3′ ends of S gene at the position of amino acid 223. The fusion gene was placed downstream of the promoter P7.5 of the universal vaccinia viral vector pGJP 5 and the recombinant vaccinia virus vS2SS1 was then selected by \%in vivo\% homogeneous recombination. Fusion protein S2SS1 could be expressed in the mammalian cells infected with vS2SS1. The investigation of expression, secretion, antigenicity and particle assembly of the S2SS1 protein demonstrated that S2SS1 protein could be assembled into particles which presented preS1, preS2 and S antigenicity and be efficiently secreted from the cells. It also showed that the level of its expression and secretion approached to that of the S protein expressed by the recombinant vaccinia virus.
文摘Despite the long availability of a traditional prophylactic vaccine containing the HBV surface antigen(HBsA g) and aluminum adjuvant, nearly 10% of the population remains unable to generate an effective immune response. Previous studies have indicated that hepatitis B virus(HBV) PreS 2-S is abundant in T/B cell epitopes, which induces a stronger immune response than HBsA g, particularly in terms of cytotoxic T lymphocyte(CTL) reaction. In the current study, the HBV PreS 2-S gene encoding an extra26 amino acids(PreS 2 C-terminus) located at the N-terminus of HBsA g was cloned into the pV CH1300 expression vector. Pre S2-S expressed in the methylotrophic yeast, Hansenula polymorpha, was produced at a yield of up to 250 mg/L. Subsequent purification steps involved hydrophobic adsorption to colloidal silica, ion-exchange chromatography and density ultracentrifugation. The final product was obtained with a total yield of ~15% and purity of ~99%. In keeping with previous studies, ~22 nm viruslike particles were detected using electron microscopy. The generated PreS 2-S antigen will be further studied for efficacy and safty in animals.
基金Supported by The National Natural Science Foundation ofChina,No.30872998
文摘AIM:To investigate the inhibitory effect of hepatitis B virus (HBV) preS2 antibody (preS2Ab) against HBV in-fection and HBV-associated hepatic carcinogenesis.METHODS:An adenoviral vector carrying the full-length light and heavy chains of the HBV preS2Ab gene,Ad315-preS2Ab,was constructed.Enzyme linked immunosorbent assay (ELISA) and Western blotting analyses were used to determine the preS2Ab expres-sion levels in vitro.Immunofluorescent techniques were used to examine the binding affinity between the expressed HBV preS2Ab and HBV-positive liver cells.ELISAs were also used to determine hepatitis B surface antigen (HBsAg) levels to assess the inhibitory effect of the preS2Ab against HBV infection in L02 cells.The inhibitory effect of preS2Ab against hepatic carcinogen-esis was studied with diethylnitrosamine (DEN)-induced hepatocellular carcinomas (HCCs) in HBV transgenic mice.RESULTS:The expression of HBV preS2Ab increased with increases in the multiplicity of infection (MOI) of Ad315-preS2Ab in L02 cells,with 350.87 ± 17.37 μg/L of preS2Ab when the MOI was 100 plaque forming units (pfu)/cell.The expressed preS2Abs could recog-nize liver cells from HBV transgenic mice.ELISA results showed that L02 cells expressing preS2Ab produced less HBsAg after treatment with the serum of HBV pa-tients than parental L02 cells expressing no preS2Ab.HBV transgenic mice treated with Ad315-preS2Ab had fewer and smaller cancerous nodes after induction with DEN than mice treated with a blank Ad315 vec-tor or untreated mice.Additionally,the administration of Ad315-preS2Ab could alleviate hepatic cirrhosis and decrease the serum levels of alanine transaminase and aspartate transaminase.CONCLUSION:Adenovirus-mediated HBV preS2Ab expression could inhibit HBV infection in L02 cells,and then inhibit DEN-induced hepatocellular carcinogenesis and protect hepatic function in HBV transgenic mice.
