2',3'-dideoxyguanosine(DoG) has been demonstrated to inhibit duck hepatitis B virus(DHBV) replication in vivo in a duck model of HBV infection. In the current study, the in vitro antiviral effects of DoG on hu...2',3'-dideoxyguanosine(DoG) has been demonstrated to inhibit duck hepatitis B virus(DHBV) replication in vivo in a duck model of HBV infection. In the current study, the in vitro antiviral effects of DoG on human and animal hepadnaviruses were investigated. Our results showed that DoG effectively inhibited HBV, DHBV, and woodchuck hepatitis virus(WHV)replication in hepatocyte-derived cells in a dose-dependent manner, with 50% effective concentrations(EC50) of 0.3 ± 0.05, 6.82 ± 0.25, and 23.0 ± 1.5 lmol/L, respectively. Similar to other hepadnaviral DNA polymerase inhibitors,DoG did not alter the levels of intracellular viral RNA but induced the accumulation of a less-than-full-length viral RNA species, which was recently demonstrated to be generated by RNase H cleavage of pgRNA. Furthermore, using a transient transfection assay, DoG showed similar antiviral activity against HBV wild-type, 3TC-resistant rtA181 V, and adefovirresistant rtN236T mutants. Our results suggest that DoG has potential as a nucleoside analogue drug with anti-HBV activity.展开更多
The woodchuck model is an excellent animal model to study hepadnaviral infection. The new progresses in this model made possible to examine the T-cell mediated immune responses in acute and chronic hepadnaviral infect...The woodchuck model is an excellent animal model to study hepadnaviral infection. The new progresses in this model made possible to examine the T-cell mediated immune responses in acute and chronic hepadnaviral infection. Recently, a new assay for cytotoxic T-cells based on detection of CD107 was established for the woodchuck model. In addition, new immunotherapeutic approaches based on combination of potent antiviral treatment and DNA-protein vaccines were proven to be useful for treatment of chronic hepatitis B.展开更多
The nucleocapsid of hepadnaviruses consisits of dimers of the core proteins. However, the mechanism of the core-core subunit interaction is not well understood. The Nterminus of the core protein of woodchuck hepatitis...The nucleocapsid of hepadnaviruses consisits of dimers of the core proteins. However, the mechanism of the core-core subunit interaction is not well understood. The Nterminus of the core protein of woodchuck hepatitis virus(WHV) was found containing four conserved hydrophobic amino acid residues (from residue 101 to 122 ). These residues, referred to the hydrophobic heptad repeat(hhr), distributed as heptad repeats in the primary sequence. Since hydrophobic bounds often play an important role in interaction of proteins, roles of the hhr region in capsid assembly of WHV were investigated using a cell culture system. The codons for these four hydrophobic amino acid residues and other related residues in this region were substituted with codons specifying alanine or proline. Phenotype of each of these mutants was examined at various stages of viral replication in Hub7 cells. It was found that single substitution of the four hydrophobic residues had no detectable effect, but substitution of the same residues in various paired combinations resulted in a complete inhibition of capsid assembly. The capsid assembly was inhibited when amino acid insertion occerred at the first and last two hydrophobic residues or a single amino acid deletion occurred at the first pair of hydrophobic residues. However, random amino acid substitutions in this region did not affect assembly. The results indicated that the hhr region of the core protein was necessory for capsid assembly of woodchuck hepatitis virus.展开更多
基金supported in part by the Program for New Century Excellent Talents in University (Program No. NCET-12-0975)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry+1 种基金Jiangsu Overseas research & training program for University Prominent Young and Middle-aged Teachers and Presidents (for Pinghu Zhang)Qinghai Province High-end Innovative Talent Thousand Talents Program (for Pinghu Zhang)
文摘2',3'-dideoxyguanosine(DoG) has been demonstrated to inhibit duck hepatitis B virus(DHBV) replication in vivo in a duck model of HBV infection. In the current study, the in vitro antiviral effects of DoG on human and animal hepadnaviruses were investigated. Our results showed that DoG effectively inhibited HBV, DHBV, and woodchuck hepatitis virus(WHV)replication in hepatocyte-derived cells in a dose-dependent manner, with 50% effective concentrations(EC50) of 0.3 ± 0.05, 6.82 ± 0.25, and 23.0 ± 1.5 lmol/L, respectively. Similar to other hepadnaviral DNA polymerase inhibitors,DoG did not alter the levels of intracellular viral RNA but induced the accumulation of a less-than-full-length viral RNA species, which was recently demonstrated to be generated by RNase H cleavage of pgRNA. Furthermore, using a transient transfection assay, DoG showed similar antiviral activity against HBV wild-type, 3TC-resistant rtA181 V, and adefovirresistant rtN236T mutants. Our results suggest that DoG has potential as a nucleoside analogue drug with anti-HBV activity.
基金Deutsche Forschungsgemeinschaft (Lu 669/2-1, GRK1045/1, and Lu 669/5-1)
文摘The woodchuck model is an excellent animal model to study hepadnaviral infection. The new progresses in this model made possible to examine the T-cell mediated immune responses in acute and chronic hepadnaviral infection. Recently, a new assay for cytotoxic T-cells based on detection of CD107 was established for the woodchuck model. In addition, new immunotherapeutic approaches based on combination of potent antiviral treatment and DNA-protein vaccines were proven to be useful for treatment of chronic hepatitis B.
文摘The nucleocapsid of hepadnaviruses consisits of dimers of the core proteins. However, the mechanism of the core-core subunit interaction is not well understood. The Nterminus of the core protein of woodchuck hepatitis virus(WHV) was found containing four conserved hydrophobic amino acid residues (from residue 101 to 122 ). These residues, referred to the hydrophobic heptad repeat(hhr), distributed as heptad repeats in the primary sequence. Since hydrophobic bounds often play an important role in interaction of proteins, roles of the hhr region in capsid assembly of WHV were investigated using a cell culture system. The codons for these four hydrophobic amino acid residues and other related residues in this region were substituted with codons specifying alanine or proline. Phenotype of each of these mutants was examined at various stages of viral replication in Hub7 cells. It was found that single substitution of the four hydrophobic residues had no detectable effect, but substitution of the same residues in various paired combinations resulted in a complete inhibition of capsid assembly. The capsid assembly was inhibited when amino acid insertion occerred at the first and last two hydrophobic residues or a single amino acid deletion occurred at the first pair of hydrophobic residues. However, random amino acid substitutions in this region did not affect assembly. The results indicated that the hhr region of the core protein was necessory for capsid assembly of woodchuck hepatitis virus.
