P450s under Restriction (PURE) Screen Using HepaRG and Primary Human Hepatocytes for Discovery of Novel HBV Antivirals

Abstract

Herein is reported a novel screening paradigm PURE (P450s under restriction) for the identification and optimization of hits as part of a hepatitis B virus (HBV) antiviral discovery program. To closely represent in vivo hepatocytes, differentiated HepaRG cells (dHRGs) and primary human hepatocytes (PHHs) were used as the basis for an HBV infection system. However, a significant challenge arose during potency evaluation in using cultured dHRGs and PHHs as screening platforms because, as with hepatocytes in vivo, these cells express active cytochrome P450 enzymes and thus can metabolize test compounds. The observed antiviral effects may be the cumulative result of a dynamic pool of parent compound and metabolites thus confounding structure activity relationship (SAR) interpretation and subsequent optimization design initiatives. We show here that PURE methodology restricts metabolism of HBV-infected dHRGs and PHHs and thus provides highly informative potency data for decision-making on key representative antiviral compounds.

Presenting a Special Issue on “Medicinal Chemistry: From Targets to Therapies”

“…Thirty-three Letters, two Viewpoints, three Innovations and three Patent Highlights have been contributed by prominent players in their respective fields. Letters cover subjects such as cyclooxygenase 1 detection (by Malerba et al), FAK-targeting PROTACs (Gao et al), a chimeric inhibitor of macrophage migration inhibitory factor (Cirillo et al), Bruton’s tyrosine kinase (BTK) inhibitors (Zhang et al), oximes for acetylcholine esterase reactivation (Gambino et al), Zika virus inhibitors (Coluccia et al), phosphodiesterase 4B (PDE4B) inhibitors (Vadukoot et al), sirtuin 1–3 inhibition (Rajabi et al), analogs of the Gram-negative antibiotic zafirlukast (Howard et al), screens for hepatitis B (HBV) antiviral discovery (Hartman et al), A 3 adenosine receptor (A 3 AR) agonists (Tosh et al), fibroblast growth factor receptor 4 (FGFR4) inhibitors (Liu et al), inactivators of γ-aminobutyric acid aminotransferase (GABA-AT) (Shen et al), bitopic agonists of dopamine D 3 R (Battiti et al), harmaline analogs as COX-2 inhibitors (Uddin et al), imaging approaches in osteoarthritis (Uddin et al), HIV-1 protease inhibitors (Ghosh et al), brain-permeable tafamidis analogs (Sinha et al), melanocortin receptor antagonists (Ericson et al), choline antimetabolites (Bollenbach et al), bromodomain and extra-terminal (BET) inhibitors (Altenburg et al), raltegravir photoaffinity labels (Pala et al), selective orexin-1 antagonists (Préville et al), folate receptor targeting agents (Jin et al), intracellular peptide delivery (Ng et al), gibberellin-based inhibitors of NF-kB (Annand et al), agonists of a cannabinoid-activated GPCR (Schoeder et al), ceramide galactosyltransferase enzyme inhibitors (Thurairatnam et al), thermoresponsive perfluorocarbon hydrogels (Herneisey et al), a sigma-2 receptor agonist that could be effective in COVID-19 (Colabufo et al), a uric acid uptake inhibitor (Uda et al), and cationic photosensitizers (Mazumdar et al) . A Featured Letter describes the discovery of A-1331852, a first-in-class orally active BCL-XL inhibitor that can serve both as a tool compound as well as a lead structure for apoptosis-inducing anticancer drugs (Wang et al) …”