title: Haploid Genetic Screen Reveals a Profound and Direct Dependence on Cholesterol for Hantavirus Membrane Fusion.
abstract: Hantaviruses cause hemorrhagic fever with renal syndrome (HFRS) in the Old World and a highly fatal hantavirus cardiopulmonary syndrome (HCPS) in the New World. No vaccines or antiviral therapies are currently available to prevent or treat hantavirus disease, and gaps in our understanding of how hantaviruses enter cells challenge the search for therapeutics. We performed a haploid genetic screen in human cells to identify host factors required for entry by Andes virus, a highly virulent New World hantavirus. We found that multiple genes involved in cholesterol sensing, regulation, and biosynthesis, including key components of the sterol response element-binding protein (SREBP) pathway, are critical for Andes virus entry. Genetic or pharmacological disruption of the membrane-bound transcription factor peptidase/site-1 protease (MBTPS1/S1P), an SREBP control element, dramatically reduced infection by virulent hantaviruses of both the Old World and New World clades but not by rhabdoviruses or alphaviruses, indicating that this pathway is broadly, but selectively, required by hantaviruses. These results could be fully explained as arising from the modest depletion of cellular membrane cholesterol that accompanied S1P disruption. Mechanistic studies of cells and with protein-free liposomes suggested that high levels of cholesterol are specifically needed for hantavirus membrane fusion. Taken together, our results indicate that the profound dependence on target membrane cholesterol is a fundamental, and unusual, biophysical property of hantavirus glycoprotein-membrane interactions during entry.
  
  
  OBJECTIVE
  Although hantaviruses cause important human diseases worldwide, no specific antiviral treatments are available. One of the major obstacles to the development of new therapies is a lack of understanding of how hantaviruses hijack our own host factors to enter cells. Here, we identified multiple cellular genes that control the levels of cholesterol in cellular membranes to be important for hantavirus entry. Our findings suggest that high concentrations of cholesterol in cellular membranes are required at a specific step in the entry process-fusion between viral and cellular membranes-that allows escape of the hantavirus genome into the host cell cytoplasm to initiate infection. Our findings uncover a fundamental feature of the hantavirus infection mechanism and point to cholesterol-lowering drugs as a potential new treatment of hantaviral infections.
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Lara M
authors.initials: LM
authors.lastname: Kleinfelter
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Rohit K
authors.initials: RK
authors.lastname: Jangra
authors.affiliation: Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Lucas T
authors.initials: LT
authors.lastname: Jae
authors.affiliation: U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Herbert
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Eva
authors.initials: E
authors.lastname: Mittler
authors.affiliation: Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Katie M
authors.initials: KM
authors.lastname: Stiles
authors.affiliation: U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, USA.
authors.forename: Ariel S
authors.initials: AS
authors.lastname: Wirchnianski
authors.affiliation: Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Margaret
authors.initials: M
authors.lastname: Kielian
authors.affiliation: Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Thijn R
authors.initials: TR
authors.lastname: Brummelkamp
authors.affiliation: U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, USA kartik.chandran@einstein.yu.edu john.m.dye1.civ@mail.mil.
authors.forename: John M
authors.initials: JM
authors.lastname: Dye
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA kartik.chandran@einstein.yu.edu john.m.dye1.civ@mail.mil.
authors.forename: Kartik
authors.initials: K
authors.lastname: Chandran
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D002784:Cholesterol / Q000378:metabolism*; D005820:Genetic Testing; D057809:HEK293 Cells; D006476:Orthohantavirus / Q000502:physiology*; D006238:Haploidy; D006801:Humans; D014709:Vero Cells; D053586:Virus Internalization
chemical_list: D002784:Cholesterol