Filovirus Antiviral Activity of Cationic Amphiphilic Drugs Is Associated with Lipophilicity and Ability To Induce Phospholipidosis

Abstract

Several cationic amphiphilic drugs (CADs) have been found to inhibit cell entry of filoviruses and other enveloped viruses. Structurally unrelated CADs may have antiviral activity, yet the underlying common mechanism and structure-activity relationship are incompletely understood. We aimed to understand how widespread antiviral activity is among CADs and which structural and physico-chemical properties are linked to entry inhibition. We measured inhibition of Marburg virus pseudoparticle (MARVpp) cell entry by 45 heterogeneous and mostly FDA-approved CADs and cytotoxicity in EA.hy926 cells. We analyzed correlation of antiviral activity with four chemical properties: pKa, hydrophobicity (octanol/water partitioning coefficient; ClogP), molecular weight, and distance between the basic group and hydrophobic ring structures. Additionally, we quantified drug-induced phospholipidosis (DIPL) of a CAD subset by flow cytometry. Structurally similar compounds (derivatives) and those with similar chemical properties but unrelated structures (analogues) to those of strong inhibitors were obtained by two in silico similarity search approaches and tested for antiviral activity. Overall, 11 out of 45 (24%) CADs inhibited MARVpp by 40% or more. The strongest antiviral compounds were dronedarone, triparanol, and quinacrine. Structure-activity relationship studies revealed highly significant correlations between antiviral activity, hydrophobicity (ClogP > 4), and DIPL. Moreover, pKa and intramolecular distance between hydrophobic and hydrophilic moieties correlated with antiviral activity but to a lesser extent. We also showed that in contrast to analogues, derivatives had antiviral activity similar to that of the seed compound dronedarone. Overall, one-quarter of CADs inhibit MARVpp entry in vitro, and antiviral activity of CADs mostly relies on their hydrophobicity yet is promoted by the individual structure.

Phospholipidosis is a shared mechanism underlying thein vitroantiviral activity of many repurposed drugs against SARS-CoV-2

“…Among the most potent in the antiviral assays were drugs like amiodarone, tamoxifen, and sertraline; CADs known to provoke phospholipidosis at relevant concentrations, a connection also made previously for filoviruses (11). Since phospholipidosis disrupts intracellular lipid homeostasis, and many viruses propagate in double membrane vesicles that may exploit the lipid pathways that are disrupted by CADs, we investigated the hypothesis that the antiviral effect we had found, and potentially found in other drug repurposing studies for COVID-19, could be explained by the drug induction of phospholipidosis.…”

“…Importantly, modulation of these same lipid processing pathways is critical for viral replication( 8 ), and inhibiting phospholipid production has previously been associated with inhibition of coronavirus replication( 9 ). CADs have been previously shown to have in vitro activity against a range of viruses such as Severe Acute Respiratory Syndrome virus, Middle East Respiratory Syndrome virus, Ebola virus, Zika virus, Dengue virus, and filoviruses( 10 ), though CAD-induction of phospholipidosis has only been proposed as a specific antiviral mechanism against Marburg virus( 11 ). Finally, many of the drugs that are best-known to induce phospholipidosis, and for which it is associated with adverse events, are amiodarone( 12 ) and chloroquine( 13, 14 ), which we( 15 ), and others ( 16, 17 ), had found to be potent inhibitors of SARS-CoV-2 replication in vitro .…”

Interdependent Impact of Lipoprotein Receptors and Lipid-Lowering Drugs on HCV Infectivity

“…HIV-based gutted Gag-Pol packaging construct, transfer plasmids CSPW (Puromycin resistance gene Puro r ) and pWPI_NanoLuc_BLR (NanoLuciferase), VSV-G, MLV env, HCV J6 E1-E2, or HCV H77 E1-E2 glycoprotein expressing vector, and pCDNA3.1 empty backbone have been previously described [ 41 , 42 , 43 ]. Full-length Jc1 firefly luciferase (FLuc) reporter construct pFKi389LucEiJFH1/J6/C-846 and HCV Con1 (pFKi 389 Neo EI Core 3′JFH1wt) have been previously described [ 44 , 45 ].…”

“…Then, cells were lysed with 35 µL/well of our in-house lysis buffer (see previous) supplemented with DTT and frozen at −80 °C until measurement. For NLuc measurement, 20 µL lysate was mixed with 80 µL coelenterazine substrate (Carl Roth, Karlsruhe, Germany), incubated for 5 min at room temperature (rt) and measured as previously described [ 42 ] using a Centro LB 960 microplate luminometer (Berthold technologies, Bad Wildbad, Germany).…”

“…After 6 h fresh DMEM complete medium was added. NLuc expression was evaluated three passages after transduction and at the end of each individual GP-mediated cell entry assay, as previously described [ 42 ].…”