BACKGROUND: HBV infection continues to be an important worldwide cause of morbidity and mortality. Patients with chronic hepatitis B can be successfully treated using nucleoside/nucleotide analogues. However, drug-resistant HBV mutants frequently arise, leading to treatment failure and progression to liver disease. Here, we report the effects of GLS4, a non-nucleosidic inhibitor that exhibits a novel and highly specific anti-HBV activity. METHODS: The median inhibitory concentrations (IC(50)s) of GLS4 on HBV were measured by Southern blotting. HBV capsid and core protein levels were detected by immunoblotting. To determine the antiviral activity of GLS4 against adefovir dipivoxil (ADV)-resistant HBV mutants, HepG2 cells transiently transfected with PUC-HBV1.2 plasmids that contained one of three major ADV-resistant mutations (rtA181T, rtA181V and rtN236T) were treated with GLS4. Intracellular HBV replicative intermediates were detected by Southern blotting. The effect on the in vitro assembly of HBV capsid protein was examined using dynamic light scattering and electron microscopy. RESULTS: The IC(50) of GLS4 was 0.012 μM, which is significantly lower than that of lamivudine (0.325 μM). Immunoblot analysis of HepG2.2.15 cells and transiently transfected HepG2 cells indicated that GLS4 treatment interfered with the formation of core particles (assembly). The ADV-resistant HBV mutant strains were also sensitive to GLS4. Upon examining the in vitro assembly of HBV core protein 149 by electron microscopy, increased aberrant particles were observed after GLS4 treatment. CONCLUSIONS: GLS4 is a new and unique potential anti-HBV agent that possesses a different mechanism of action than existing therapeutic drugs.
BACKGROUND:HBV infection continues to be an important worldwide cause of morbidity and mortality. Patients with chronic hepatitis B can be successfully treated using nucleoside/nucleotide analogues. However, drug-resistant HBV mutants frequently arise, leading to treatment failure and progression to liver disease. Here, we report the effects of GLS4, a non-nucleosidic inhibitor that exhibits a novel and highly specific anti-HBV activity. METHODS: The median inhibitory concentrations (IC(50)s) of GLS4 on HBV were measured by Southern blotting. HBV capsid and core protein levels were detected by immunoblotting. To determine the antiviral activity of GLS4 against adefovir dipivoxil (ADV)-resistant HBV mutants, HepG2 cells transiently transfected with PUC-HBV1.2 plasmids that contained one of three major ADV-resistant mutations (rtA181T, rtA181V and rtN236T) were treated with GLS4. Intracellular HBV replicative intermediates were detected by Southern blotting. The effect on the in vitro assembly of HBV capsid protein was examined using dynamic light scattering and electron microscopy. RESULTS: The IC(50) of GLS4 was 0.012 μM, which is significantly lower than that of lamivudine (0.325 μM). Immunoblot analysis of HepG2.2.15 cells and transiently transfected HepG2 cells indicated that GLS4 treatment interfered with the formation of core particles (assembly). The ADV-resistant HBV mutant strains were also sensitive to GLS4. Upon examining the in vitro assembly of HBV core protein 149 by electron microscopy, increased aberrant particles were observed after GLS4 treatment. CONCLUSIONS:GLS4 is a new and unique potential anti-HBV agent that possesses a different mechanism of action than existing therapeutic drugs.
Authors: Nagraj Mani; Andrew G Cole; Janet R Phelps; Andrzej Ardzinski; Kyle D Cobarrubias; Andrea Cuconati; Bruce D Dorsey; Ellen Evangelista; Kristi Fan; Fang Guo; Haitao Guo; Ju-Tao Guo; Troy O Harasym; Salam Kadhim; Steven G Kultgen; Amy C H Lee; Alice H L Li; Quanxin Long; Sara A Majeski; Richeng Mao; Kevin D McClintock; Stephen P Reid; Rene Rijnbrand; Nicholas M Snead; Holly M Micolochick Steuer; Kim Stever; Sunny Tang; Xiaohe Wang; Qiong Zhao; Michael J Sofia Journal: Antimicrob Agents Chemother Date: 2018-05-25 Impact factor: 5.191
Authors: Klaus Klumpp; Angela M Lam; Christine Lukacs; Robert Vogel; Suping Ren; Christine Espiritu; Ruth Baydo; Kateri Atkins; Jan Abendroth; Guochun Liao; Andrey Efimov; George Hartman; Osvaldo A Flores Journal: Proc Natl Acad Sci U S A Date: 2015-11-23 Impact factor: 11.205