Identification of filovirus entry inhibitors targeting the endosomal receptor NPC1 binding site

Leah Liu Wang; Nicholas Palermo; Leslie Estrada; Colton Thompson; J J Patten; Manu Anantpadma; Robert A Davey; Shi-Hua Xiang

doi:10.1016/j.antiviral.2021.105059

Identification of filovirus entry inhibitors targeting the endosomal receptor NPC1 binding site

Antiviral Res. 2021 May:189:105059. doi: 10.1016/j.antiviral.2021.105059. Epub 2021 Mar 8.

Authors

Leah Liu Wang¹, Nicholas Palermo², Leslie Estrada³, Colton Thompson³, J J Patten⁴, Manu Anantpadma⁴, Robert A Davey⁴, Shi-Hua Xiang⁵

Affiliations

¹ School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA; Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
² Computational Chemistry Core Facility, VCR Cores, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
³ Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
⁴ National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, 0211, USA.
⁵ School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA; Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA. Electronic address: sxiang2@unl.edu.

Abstract

Filoviruses, mainly consisting of Ebola viruses (EBOV) and Marburg viruses (MARV), are enveloped negative-strand RNA viruses which can infect humans to cause severe hemorrhagic fevers and outbreaks with high mortality rates. The filovirus infection is mediated by the interaction of viral envelope glycoprotein (GP) and the human endosomal receptor Niemann-Pick C1 (NPC1). Blocking this interaction will prevent the infection. Therefore, we utilized an In silico screening approach to conduct virtual compound screening against the NPC1 receptor-binding site (RBS). Twenty-six top-hit compounds were purchased and evaluated by in vitro cell based inhibition assays against pseudotyped or replication-competent filoviruses. Two classes (A and U) of compounds were identified to have potent inhibitory activity against both Ebola and Marburg viruses. The IC₅₀ values are in the lower level of micromolar concentrations. One compound (compd-A) was found to have a sub-micromolar IC₅₀ value (0.86 μM) against pseudotyped Marburg virus. The cytotoxicity assay (MTT) indicates that compd-A has a moderate cytotoxicity level but the compd-U has much less toxicity and the CC₅₀ value was about 100 μM. Structure-activity relationship (SAR) study has found some analogs of compd-A and -U have reduced the toxicity and enhanced the inhibitory activity. In conclusion, this work has identified several qualified lead-compounds for further drug development against filovirus infection.

Keywords: Entry inhibitors; Envelope glycoprotein (GP); Filovirus; In silico screening; Niemann-pick C1 (NPC1); Receptor binding site (RBS).

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Antiviral Agents / chemistry
Antiviral Agents / pharmacology*
Binding Sites
Cell Survival
Drug Discovery
Ebolavirus / drug effects*
Ebolavirus / physiology
Filoviridae Infections / drug therapy
Filoviridae Infections / virology*
HeLa Cells
Host Microbial Interactions / drug effects
Humans
Inhibitory Concentration 50
Marburgvirus / drug effects*
Marburgvirus / physiology
Molecular Docking Simulation
Niemann-Pick C1 Protein / chemistry
Niemann-Pick C1 Protein / metabolism*
Protein Binding
Receptors, Virus / chemistry
Receptors, Virus / metabolism
Viral Envelope Proteins / metabolism*
Virus Internalization / drug effects*

Substances

Antiviral Agents
NPC1 protein, human
Niemann-Pick C1 Protein
Receptors, Virus
Viral Envelope Proteins

Abstract

Publication types

MeSH terms

Substances

Grants and funding