1397. The Niemann-Pick C1 protein is a critical endosomal host factor for filovirus entry
Session: Oral Abstract Session: Host Susceptibility to Viral Infections
Sunday, October 23, 2011: 7:30 AM
Room: 156ABC
Background: Infections by the Ebola (EboV) and Marburg (MarV) filoviruses cause a rapidly fatal hemorrhagic fever in humans for which no approved vaccines or antivirals are available. Filovirus entry into cells is mediated by the viral spike glycoprotein GP, which attaches viral particles to the cell surface, delivers them to endosomes, and catalyzes fusion between viral and endosomal membranes. Within endosomes, GP undergoes proteolysis by host cysteine proteases to generate a ‘primed’ GP intermediate (GP17K) that is necessary, but not sufficient, for viral entry – additional endosomal host factors, including a putative entry receptor, are thought to act on GP17K to induce viral membrane fusion. Despite considerable efforts, however, these critical host factors have defied molecular identification.

Methods: We performed a genome-wide haploid genetic screen in human cells to identify host factors required for EboV GP-mediated entry.

Results: Our screen uncovered 39 independent mutations that disrupt the endosomal cholesterol transporter protein Niemann-Pick C1 (NPC1). Cells defective for NPC1, including primary fibroblasts derived from human Niemann-Pick disease patients, were resistant to infection by EboV and MarV but fully susceptible to a suite of unrelated viruses. Moreover, heterozygous NPC1 knockout mice, but not their wild-type littermates, survived after challenge with mouse-adapted EboV and MarV

Conclusion: 

Therefore, NPC1 is a critical endosomal host factor for filovirus infection both in vitro and in vivo. Ongoing work is aimed at delineating NPC1’s role at one or more steps in filovirus entry within host cell endosomes.


Subject Category: V. Virology including clinical and basic studies of viral infections, including hepatitis

Anuja Krishnan1, Jan Carette2, Anthony Wong3, Matthijs Raaben4, Emily Miller3, Andrew Herbert5, Gregor Obernosterer6, Nirupama Mulherkar3, Ana Kuehne7, Rohini Sandesara8, John Dye9, Sean Whelan10, Thijn Brummelkamp11 and Kartik Chandran3, (1)Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, (2)Department of Microbiology and Immunology, Stanford, CA, (3)Albert Einstein College of Medicine , Bronx, NY, (4)Harvard Medical School, Boston, MA, (5)U.S. Army Medical Research Institute of Infectious Diseases, Maryland, MD, (6)Netherlands Cancer Institute, Amsterdam, , Netherlands, (7)U.S. Army Medical Research Institute of Infectious Diseases, , Maryland , Maryland, MD, (8)Department of Microbiology & Immunology , Bronx, NY, (9)U.S. Army Medical Research Institute of Infectious Diseases, , Maryland , MD, (10)Harvard Medical School, , Boston, MA, (11)Netherlands Cancer Institute, , Amsterdam, Netherlands

Disclosures:

A. Krishnan, None

J. Carette, None

A. Wong, None

M. Raaben, None

E. Miller, None

A. Herbert, None

G. Obernosterer, None

N. Mulherkar, None

A. Kuehne, None

R. Sandesara, None

J. Dye, None

S. Whelan, None

T. Brummelkamp, None

K. Chandran, None

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