TY - JOUR
T1 - Identification and characterization of a novel hepatitis B virus pregenomic RNA encapsidation inhibitor
AU - Jo, Eunji
AU - Ryu, Dong Kyun
AU - König, Alexander
AU - Park, Soonju
AU - Cho, Yoojin
AU - Park, Sang Hyun
AU - Kim, Tae Hee
AU - Yoon, Seung Kew
AU - Ryu, Wang Shick
AU - Cechetto, Jonathan
AU - Windisch, Marc P.
N1 - Funding Information:
This study was supported by the National Research Foundation of Korea (MSIT 2017M3A9G6068246 and NRF-2014R1A2A1A11052535 ) and the Gyeonggi Provincial Government .
Publisher Copyright:
© 2020
PY - 2020/3
Y1 - 2020/3
N2 - Currently, therapies to treat chronic hepatitis B (CHB) infection are based on the use of interferon-α or nucleos(t)ide analogs (NAs) to prevent viral DNA synthesis by inhibiting the reverse transcriptase activity of the hepatitis B virus (HBV) polymerase (Pol). However, these therapies are not curative; thus, the development of novel anti-HBV agents is needed. In accordance with this unmet medical need, we devised a new target- and cell-based, high-throughput screening assay to identify novel small molecules that block the initial interaction of the HBV Pol with its replication template the viral pregenomic RNA (pgRNA). We screened approximately 110,000 small molecules for the ability to prevent HBV Pol recognition of the pgRNA 5′ epsilon (ε) stem-loop structure, identifying (Z)-2-(allylamino)-4-amino-N′-cyanothiazole-5-carboximidamide (AACC). Viral nucleocapsid-captured quantitative RT-PCR and Western blot results revealed that AACC significantly decreased encapsidated pgRNA levels and blocked capsid assembly without affecting core protein expression in stable HBV-replicating cells. As a result, both intra- and extracellular accumulation of viral DNA was strongly reduced. AACC treatment of HepG2-sodium taurocholate transporting polypeptide (NTCP) cells and primary human hepatocytes infected with cell culture- or patient-derived HBV isolates showed both time- and dose-dependent inhibition of infectious viral progeny and rcDNA production. Furthermore, AACC showed cross-genotypic activity against genotypes B, C, and D. Of note, AACC inhibited the viral replication of lamivudine and a capsid inhibitor-resistant HBV, and showed synergistic effects with NAs and a capsid inhibitor. In conclusion, we identified a novel class of compounds specifically targeting the ε-Pol interaction and thereby preventing the encapsidation of pgRNAs into viral capsids. This promising new HBV inhibitor class potently inhibits HBV amplification with distinct characteristics from existing NAs and other drugs currently under development, promising to add value to existing therapies for CHB.
AB - Currently, therapies to treat chronic hepatitis B (CHB) infection are based on the use of interferon-α or nucleos(t)ide analogs (NAs) to prevent viral DNA synthesis by inhibiting the reverse transcriptase activity of the hepatitis B virus (HBV) polymerase (Pol). However, these therapies are not curative; thus, the development of novel anti-HBV agents is needed. In accordance with this unmet medical need, we devised a new target- and cell-based, high-throughput screening assay to identify novel small molecules that block the initial interaction of the HBV Pol with its replication template the viral pregenomic RNA (pgRNA). We screened approximately 110,000 small molecules for the ability to prevent HBV Pol recognition of the pgRNA 5′ epsilon (ε) stem-loop structure, identifying (Z)-2-(allylamino)-4-amino-N′-cyanothiazole-5-carboximidamide (AACC). Viral nucleocapsid-captured quantitative RT-PCR and Western blot results revealed that AACC significantly decreased encapsidated pgRNA levels and blocked capsid assembly without affecting core protein expression in stable HBV-replicating cells. As a result, both intra- and extracellular accumulation of viral DNA was strongly reduced. AACC treatment of HepG2-sodium taurocholate transporting polypeptide (NTCP) cells and primary human hepatocytes infected with cell culture- or patient-derived HBV isolates showed both time- and dose-dependent inhibition of infectious viral progeny and rcDNA production. Furthermore, AACC showed cross-genotypic activity against genotypes B, C, and D. Of note, AACC inhibited the viral replication of lamivudine and a capsid inhibitor-resistant HBV, and showed synergistic effects with NAs and a capsid inhibitor. In conclusion, we identified a novel class of compounds specifically targeting the ε-Pol interaction and thereby preventing the encapsidation of pgRNAs into viral capsids. This promising new HBV inhibitor class potently inhibits HBV amplification with distinct characteristics from existing NAs and other drugs currently under development, promising to add value to existing therapies for CHB.
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U2 - 10.1016/j.antiviral.2020.104709
DO - 10.1016/j.antiviral.2020.104709
M3 - Article
C2 - 31940474
AN - SCOPUS:85078183290
VL - 175
JO - Antiviral Research
JF - Antiviral Research
SN - 0166-3542
M1 - 104709
ER -
