Details

Autor(en) / Beteiligte

• Chauhan, Ranjit
• Li, Qilan
• Woodson, Molly E
• Gasonoo, Makafui
• Meyers, Marvin J
• Tavis, John E

Titel

Efficient Inhibition of Hepatitis B Virus (HBV) Replication and cccDNA Formation by HBV Ribonuclease H Inhibitors during Infection

Ist Teil von

• Antimicrobial agents and chemotherapy, 2021-11, Vol.65 (12), p.e0146021

Ort / Verlag

United States: American Society for Microbiology

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• The hepatitis B virus (HBV) ribonuclease H (RNase H) is an attractive but unexploited drug target. Here, we addressed three limitations to the current state of RNase H inhibitor development: (a) Efficacy has been assessed only in transfected cell lines. (b) Cytotoxicity data are from transformed cell lines rather than primary cells. (c) It is unknown how the compounds work against nucleos(t)ide analog resistant HBV strains. Three RNase H inhibitors from different chemotypes, 110 (α-hydroxytropolone), 1133 ( -hydroxypyridinedione), and 1073 ( -hydroxynapthyridinone), were tested in HBV-infected HepG2-NTCP cells for inhibition of cccDNA accumulation and HBV product formation. 50% effective concentrations (EC s) were 0.049-0.078 μM in the infection studies compared to 0.29-1.6 μM in transfected cells. All compounds suppressed cccDNA formation by >98% at 5 μM when added shortly after infection. HBV RNA, intracellular and extracellular DNA, and HBsAg secretion were all robustly suppressed. The greater efficacy of the inhibitors when added shortly after infection is presumably due to blocking amplification of the HBV cccDNA, which suppresses events downstream of cccDNA formation. The compounds had 50% cytotoxic concentrations (CC s) of 16-100 μM in HepG2-derived cell lines but were nontoxic in primary human hepatocytes, possibly due to the quiescent state of the hepatocytes. The compounds had similar EC s against replication of wild-type, lamivudine-resistant, and adefovir/lamivudine-resistant HBV, as expected because the RNase H inhibitors do not target the viral reverse transcriptase active site. These studies expand confidence in inhibiting the HBV RNase H as a drug strategy and support inclusion of RNase H inhibitors in novel curative drug combinations for HBV.