Unique Small Molecule Entry Inhibitors of Hemorrhagic Fever Arenaviruses

doi:10.1074/jbc.M802089200

Unique Small Molecule Entry Inhibitors of Hemorrhagic Fever Arenaviruses^*

Andrew M. Lee^‡,
Jillian M. Rojek^‡,
Christina F. Spiropoulou^§,
Anette T. Gundersen^‡¹,
Wei Jin^¶,
Alex Shaginian^¶,
Joanne York^∥,
Jack H. Nunberg^∥,
Dale L. Boger^¶,
Michael B. A. Oldstone^‡^** and
Stefan Kunz, Supported by a Medical Research Award from the Foundation Prof. Dr. Max Cloetta (Switzerland)^‡^‡‡²

Departments of ^‡Immunology and Microbial Science, ^¶Chemistry, and ^**Infectology, The Scripps Research Institute, La Jolla, California 92037, the ^§Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, the ^∥Montana Biotechnology Center, The University of Montana, Missoula, Montana 59812, and the ^‡‡Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011, Switzerland

2 To whom correspondence should be addressed: Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011, Switzerland. Tel.: 41-21-314-7743; Fax: 41-21-314-4060; E-mail: Stefan.Kunz{at}chuv.ch.

Abstract

Viral hemorrhagic fevers caused by the arenaviruses Lassa virus in Africa and Machupo, Guanarito, Junin, and Sabia virus in South America are among the most devastating emerging human diseases with fatality rates of 15–35% and a limited antiviral therapeutic repertoire available. Here we used high throughput screening of synthetic combinatorial small molecule libraries to identify inhibitors of arenavirus infection using pseudotyped virion particles bearing the glycoproteins (GPs) of highly pathogenic arenaviruses. Our screening efforts resulted in the discovery of a series of novel small molecule inhibitors of viral entry that are highly active against both Old World and New World hemorrhagic arenaviruses. We observed potent inhibition of infection of human and primate cells with live hemorrhagic arenaviruses (IC₅₀ = 500–800 nm). Investigations of the mechanism of action revealed that the candidate compounds efficiently block pH-dependent fusion by the arenavirus GPs (IC₅₀ of 200–350 nm). Although our lead compounds were potent against phylogenetically distant arenaviruses, they did not show activity against other enveloped viruses with class I viral fusion proteins, indicating specificity for arenavirus GP-mediated membrane fusion.

Footnotes

↵3 The abbreviations used are: LASV, Lassa fever virus; JUNV, Junin virus; GTOV, Guanarito virus; MACV, Machupo virus; VSV, vesicular stomatitis virus; GP, glycoprotein; α-DG, α-dystroglycan; TfR1, transferrin receptor 1; HTS, high throughput screening; HF, hemorrhagic fever; TACV, Tacaribe virus; WWAV, Whitewater Arroyo virus.
↵* This work was supported, in whole or in part, by National Institutes of Health Grants AI55540, CA78045 (to D. L. B.), and 1U54 AI065359 from the United States Public Health Service. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵ The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. S1–S2.
↵1 Submitted in partial fulfillment of the requirements for a master's degree at the University of Oslo.
- Received March 17, 2008.
- Revision received May 8, 2008.
The American Society for Biochemistry and Molecular Biology, Inc.