title: Adaptive mutations in a human immunodeficiency virus type 1 envelope protein with a truncated V3 loop restore function by improving interactions with CD4.
abstract: We previously reported that a human immunodeficiency virus type 1 (HIV-1) clade B envelope protein with a severely truncated V3 loop regained function after passage in tissue culture. The adapted virus, termed TA1, retained the V3 truncation, was exquisitely sensitive to neutralization by the CD4 binding site monoclonal antibody b12 and by HIV-positive human sera, used CCR5 to enter cells, and was completely resistant to small molecule CCR5 antagonists. To examine the mechanistic basis for these properties, we singly and in combination introduced each of the 5 mutations from the adapted clone TA1 into the unadapted envelope. We found that single amino acid changes in the C3 region, the V3 loop, and in the fusion peptide were responsible for imparting near-normal levels of envelope function to TA1. T342A, which resulted in the loss of a highly conserved glycosylation site in C3, played the primary role. The adaptive amino acid changes had no impact on CCR5 antagonist resistance but made virus more sensitive to neutralization by antibodies to the CD4 binding site, modestly enhanced affinity for CD4, and made TA1 more responsive to CD4 binding. Specifically, TA1 was triggered by soluble CD4 more readily than the parental Env and, unlike the parental Env, could mediate entry on cells that express low levels of CD4. In contrast, TA1 interacted with CCR5 less efficiently and was highly sensitive to antibodies that bind to the CCR5 N terminus and ECL2. Therefore, enhanced utilization of CD4 is one mechanism by which HIV-1 can overcome mutations in the V3 region that negatively affect CCR5 interactions.
authors.affiliation: Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Caroline
authors.initials: C
authors.lastname: Agrawal-Gamse
authors.forename: Fang-Hua
authors.initials: FH
authors.lastname: Lee
authors.forename: Beth
authors.initials: B
authors.lastname: Haggarty
authors.forename: Andrea P O
authors.initials: AP
authors.lastname: Jordan
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Yi
authors.forename: Benhur
authors.initials: B
authors.lastname: Lee
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Collman
authors.forename: James A
authors.initials: JA
authors.lastname: Hoxie
authors.forename: Robert W
authors.initials: RW
authors.lastname: Doms
authors.forename: Meg M
authors.initials: MM
authors.lastname: Laakso
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics; D000818:Animals; D019380:Anti-HIV Agents / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D065100:CCR5 Receptor Antagonists; D015704:CD4 Antigens / Q000276:immunology*; D002460:Cell Line; D003510:Cyclohexanes / Q000378:metabolism; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D000077592:Maraviroc; D009154:Mutation; D019713:Receptors, CCR5 / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D014230:Triazoles / Q000378:metabolism
chemical_list: D019380:Anti-HIV Agents; D000911:Antibodies, Monoclonal; D065100:CCR5 Receptor Antagonists; D015704:CD4 Antigens; D003510:Cyclohexanes; D015699:HIV Envelope Protein gp120; D019713:Receptors, CCR5; D011994:Recombinant Proteins; D014230:Triazoles; C076613:recombinant soluble CD4; D000077592:Maraviroc
references.citation: Proc Natl Acad Sci U S A. 2000 May 9;97(10):5639-44
references.pmid: 10779565
references.citation: J Virol. 2003 Oct;77(19):10557-65
references.pmid: 12970440
references.citation: J Virol. 2008 Jan;82(2):664-73
references.pmid: 17977968
references.citation: J Virol. 1997 Sep;71(9):7136-9
references.pmid: 9261451
references.citation: Nat Med. 1996 Nov;2(11):1244-7
references.pmid: 8898753
references.citation: J Virol. 2002 Mar;76(6):3059-64
references.pmid: 11861874
references.citation: J Gen Virol. 2001 Aug;82(Pt 8):1807-1814
references.pmid: 11457985
references.citation: Virology. 2004 Oct 10;328(1):74-88
references.pmid: 15380360
references.citation: J Virol. 1994 Sep;68(9):5509-22
references.pmid: 8057433
references.citation: Virology. 2006 May 25;349(1):41-54
references.pmid: 16494916
references.citation: J Gen Virol. 1996 Jul;77 ( Pt 7):1403-10
references.pmid: 8757980
references.citation: J Virol. 2005 Jul;79(14):9069-80
references.pmid: 15994801
references.citation: J Biol Chem. 2006 May 5;281(18):12688-98
references.pmid: 16476734
references.citation: Methods Enzymol. 1997;288:118-33
references.pmid: 9356991
references.citation: J Virol. 1998 Aug;72(8):6332-8
references.pmid: 9658072
references.citation: J Virol. 2009 Nov;83(21):11016-26
references.pmid: 19692480
references.citation: J Virol. 2005 Mar;79(6):3500-8
references.pmid: 15731244
references.citation: Dev Biol Stand. 1990;72:315-41
references.pmid: 2282990
references.citation: J Virol. 1994 Feb;68(2):654-60
references.pmid: 7507183
references.citation: Proc Natl Acad Sci U S A. 2002 Dec 10;99(25):16249-54
references.pmid: 12444251
references.citation: Virology. 2006 Jul 20;351(1):226-36
references.pmid: 16631222
references.citation: Cell. 1996 Jun 28;85(7):1135-48
references.pmid: 8674119
references.citation: Science. 1998 Jun 19;280(5371):1884-8
references.pmid: 9632381
references.citation: Virology. 1995 Feb 1;206(2):935-44
references.pmid: 7531918
references.citation: J Virol. 2007 Sep;81(18):9956-66
references.pmid: 17609282
references.citation: J Virol. 2005 Sep;79(17):11161-9
references.pmid: 16103167
references.citation: Proc Natl Acad Sci U S A. 1999 Apr 27;96(9):5215-20
references.pmid: 10220446
references.citation: Virology. 2009 May 10;387(2):296-302
references.pmid: 19303620
references.citation: Mol Pharmacol. 2005 Apr;67(4):1268-82
references.pmid: 15644495
references.citation: Cell. 1996 Nov 15;87(4):745-56
references.pmid: 8929542
references.citation: Annu Rev Immunol. 1999;17:657-700
references.pmid: 10358771
references.citation: Nature. 1998 Jun 18;393(6686):648-59
references.pmid: 9641677
references.citation: PLoS Pathog. 2009 Apr;5(4):e1000377
references.pmid: 19360131
references.citation: AIDS Res Hum Retroviruses. 2000 May 20;16(8):741-9
references.pmid: 10826481
references.citation: J Virol. 1993 Jul;67(7):3978-88
references.pmid: 7685405
references.citation: Virology. 2005 Jun 5;336(2):184-97
references.pmid: 15892960
references.citation: J Biol Chem. 1999 Apr 2;274(14):9617-26
references.pmid: 10092648
references.citation: J Mol Biol. 2007 Nov 16;374(1):64-79
references.pmid: 17920626
references.citation: J Mol Biol. 2005 Jul 22;350(4):699-712
references.pmid: 15964018
references.citation: J Virol. 2001 Jun;75(12):5541-9
references.pmid: 11356961
references.citation: J Exp Med. 1997 Oct 20;186(8):1373-81
references.pmid: 9334377
references.citation: J Virol. 2001 Nov;75(22):10766-78
references.pmid: 11602718
references.citation: PLoS Pathog. 2007 Aug 24;3(8):e117
references.pmid: 17722977
references.citation: Virology. 2000 Jun 5;271(2):240-7
references.pmid: 10860877
references.citation: Proc Natl Acad Sci U S A. 1989 Sep;86(17):6768-72
references.pmid: 2771954
references.citation: J Biol Chem. 2000 Oct 27;275(43):33516-21
references.pmid: 10938094
references.citation: J Virol. 2004 Apr;78(8):4029-36
references.pmid: 15047819
references.citation: Proc Natl Acad Sci U S A. 1988 Mar;85(6):1932-6
references.pmid: 2450351
references.citation: J Virol. 2000 Nov;74(21):10074-80
references.pmid: 11024136
references.citation: Science. 2005 Nov 11;310(5750):1025-8
references.pmid: 16284180
references.citation: J Virol. 2003 May;77(9):5201-8
references.pmid: 12692222
references.citation: J Cell Biol. 2000 Oct 16;151(2):F9-14
references.pmid: 11038194
references.citation: J Virol. 2002 Sep;76(17):8953-7
references.pmid: 12163614
references.citation: Science. 2007 Sep 28;317(5846):1930-4
references.pmid: 17901336
references.citation: Science. 1986 Nov 28;234(4780):1120-3
references.pmid: 2430333
references.citation: AIDS Res Hum Retroviruses. 1995 Feb;11(2):239-48
references.pmid: 7742038
references.citation: J Virol. 1995 Sep;69(9):5723-33
references.pmid: 7543586
references.citation: J Virol. 1992 Apr;66(4):1875-83
references.pmid: 1548744
references.citation: AIDS Res Hum Retroviruses. 1992 Sep;8(9):1611-8
references.pmid: 1457207
references.citation: Curr HIV Res. 2007 Nov;5(6):507-13
references.pmid: 18045108
references.citation: J Virol. 2001 Jun;75(11):5230-9
references.pmid: 11333905
references.citation: J Virol. 2007 Mar;81(5):2359-71
references.pmid: 17182681
references.citation: J Virol. 2009 Feb;83(3):1523-31
references.pmid: 19019953
references.citation: AIDS Res Hum Retroviruses. 2005 Feb;21(2):171-89
references.pmid: 15725757
references.citation: Science. 1990 Dec 14;250(4987):1590-3
references.pmid: 1703322
references.citation: J Virol. 2005 Oct;79(19):12148-63
references.pmid: 16160142
references.citation: J Virol. 1992 May;66(5):2934-42
references.pmid: 1560532
references.citation: J Virol. 1993 Aug;67(8):4557-65
references.pmid: 8331723
references.citation: AIDS Res Hum Retroviruses. 1994 Nov;10(11):1387-400
references.pmid: 7888192
references.citation: J Virol. 2000 Aug;74(15):7005-15
references.pmid: 10888639
references.citation: J Virol. 1997 Sep;71(9):6305-14
references.pmid: 9261347