title: Cell-specific establishment of poliovirus resistance to an inhibitor targeting a cellular protein.
abstract: It is hypothesized that targeting stable cellular factors involved in viral replication instead of virus-specific proteins may raise the barrier for development of resistant mutants, which is especially important for highly adaptable small (+)RNA viruses. However, contrary to this assumption, the accumulated evidence shows that these viruses easily generate mutants resistant to the inhibitors of cellular proteins at least in some systems. We investigated here the development of poliovirus resistance to brefeldin A (BFA), an inhibitor of the cellular protein GBF1, a guanine nucleotide exchange factor for the small cellular GTPase Arf1. We found that while resistant viruses can be easily selected in HeLa cells, they do not emerge in Vero cells, in spite that in the absence of the drug both cultures support robust virus replication. Our data show that the viral replication is much more resilient to BFA than functioning of the cellular secretory pathway, suggesting that the role of GBF1 in the viral replication is independent of its Arf activating function. We demonstrate that the level of recruitment of GBF1 to the replication complexes limits the establishment and expression of a BFA resistance phenotype in both HeLa and Vero cells. Moreover, the BFA resistance phenotype of poliovirus mutants is also cell type dependent in different cells of human origin and results in a fitness loss in the form of reduced efficiency of RNA replication in the absence of the drug. Thus, a rational approach to the development of host-targeting antivirals may overcome the superior adaptability of (+)RNA viruses.
  
  
  OBJECTIVE
  Compared to the number of viral diseases, the number of available vaccines is miniscule. For some viruses vaccine development has not been successful after multiple attempts, and for many others vaccination is not a viable option. Antiviral drugs are needed for clinical practice and public health emergencies. However, viruses are highly adaptable and can easily generate mutants resistant to practically any compounds targeting viral proteins. An alternative approach is to target stable cellular factors recruited for the virus-specific functions. In the present study, we analyzed the factors permitting and restricting the establishment of the resistance of poliovirus, a small (+)RNA virus, to brefeldin A (BFA), a drug targeting a cellular component of the viral replication complex. We found that the emergence and replication potential of resistant mutants is cell type dependent and that BFA resistance reduces virus fitness. Our data provide a rational approach to the development of antiviral therapeutics targeting host factors.
authors: Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA.
authors: Ekaterina G
authors: EG
authors: Viktorova
authors: Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA.
authors: Jules
authors: J
authors: Nchoutmboube
authors: Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA.
authors: Lauren A
authors: LA
authors: Ford-Siltz
authors: Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, Maryland, USA gbelov@umd.edu.
authors: George A
authors: GA
authors: Belov
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D020126:Brefeldin A / Q000494:pharmacology*; D002522:Chlorocebus aethiops; D004351:Drug Resistance / Q000235:genetics*; D018274:Electroporation; D020662:Guanine Nucleotide Exchange Factors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D017955:Poliovirus / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014162:Transfection / Q000379:methods; D014709:Vero Cells
chemical_list: C120445:GBF1 protein, human; D020662:Guanine Nucleotide Exchange Factors; D020126:Brefeldin A; D020823:ADP-Ribosylation Factor 1
references: J Virol. 2011 Mar;85(5):2364-72
references: 21177810
references: J Cell Sci. 2007 Nov 15;120(Pt 22):3929-40
references: 17956946
references: Biochem Pharmacol. 2012 Jan 15;83(2):185-92
references: 21889497
references: Cell Struct Funct. 2011;36(2):223-35
references: 22185782
references: Curr Opin Virol. 2011 Dec;1(6):643-8
references: 22440922
references: Cell Res. 2012 Nov;22(11):1576-92
references: 22945356
references: J Biol Chem. 2013 Apr 19;288(16):11532-45
references: 23386609
references: Nature. 2014 Jan 30;505(7485):686-90
references: 24284629
references: Cell Mol Life Sci. 2014 Sep;71(18):3419-38
references: 24728583
references: Trends Cell Biol. 2000 Feb;10(2):60-7
references: 10652516
references: Proc Natl Acad Sci U S A. 2000 Dec 5;97(25):13790-5
references: 11095746
references: J Virol. 2001 Sep;75(17):8158-65
references: 11483761
references: J Virol. 2002 Nov;76(21):11113-22
references: 12368353
references: Biochem Biophys Res Commun. 2003 Mar 28;303(1):160-9
references: 12646181
references: J Virol. 2003 Nov;77(21):11408-16
references: 14557626
references: Mol Cell. 2003 Dec;12(6):1403-11
references: 14690595
references: J Virol. 2004 Apr;78(7):3378-86
references: 15016860
references: J Gen Virol. 2004 Apr;85(Pt 4):933-46
references: 15039536
references: Virology. 1968 Jul;35(3):408-17
references: 4298649
references: J Virol. 1988 Aug;62(8):2922-8
references: 2839711
references: J Virol. 1992 Apr;66(4):1985-94
references: 1312615
references: Virology. 1992 Nov;191(1):166-75
references: 1329315
references: Dev Biol Stand. 1993;78:39-53
references: 8388831
references: Arch Virol Suppl. 1994;9:159-72
references: 8032247
references: J Virol. 1995 Sep;69(9):5516-27
references: 7636997
references: Virus Res. 2005 Feb;107(2):173-81
references: 15649563
references: Mol Biol Cell. 2005 Mar;16(3):1213-22
references: 15616190
references: J Virol. 2006 Jun;80(11):5327-37
references: 16699013
references: Biologicals. 2006 Jun;34(2):163-6
references: 16682218
references: Mol Biol Cell. 2008 Feb;19(2):523-35
references: 18003980
references: PLoS Pathog. 2008 Nov;4(11):e1000216
references: 19023417
references: Science. 2009 Apr 3;324(5923):55-9
references: 19213880
references: Mol Genet Genomics. 2009 Oct;282(4):329-50
references: 19669794
references: J Virol. 2009 Nov;83(22):11940-9
references: 19740986
references: Cell. 2010 May 28;141(5):799-811
references: 20510927
references: Cell Microbiol. 2010 Oct;12(10):1463-79
references: 20497182
references: Eur Respir J. 2011 Jan;37(1):5-7
references: 21205709
references: Dev Cell. 2006 Aug;11(2):191-201
references: 16890159
references: J Cell Sci. 2006 Sep 15;119(Pt 18):3743-53
references: 16926190
references: J Virol. 2006 Dec;80(23):11852-60
references: 17005635
references: Genes Dev. 2007 Jan 15;21(2):195-205
references: 17234885
references: J Virol. 2007 May;81(10):5238-45
references: 17329336
references: J Virol. 2011 May;85(9):4284-96
references: 21345960