title: Isolation of a high affinity neutralizing monoclonal antibody against 2009 pandemic H1N1 virus that binds at the 'Sa' antigenic site.
abstract: Influenza virus evades host immunity through antigenic drift and shift, and continues to circulate in the human population causing periodic outbreaks including the recent 2009 pandemic. A large segment of the population was potentially susceptible to this novel strain of virus. Historically, monoclonal antibodies (MAbs) have been fundamental tools for diagnosis and epitope mapping of influenza viruses and their importance as an alternate treatment option is also being realized. The current study describes isolation of a high affinity (K(D) = 2.1±0.4 pM) murine MAb, MA2077 that binds specifically to the hemagglutinin (HA) surface glycoprotein of the pandemic virus. The antibody neutralized the 2009 pandemic H1N1 virus in an in vitro microneutralization assay (IC(50) = 0.08 µg/ml). MA2077 also showed hemagglutination inhibition activity (HI titre of 0.50 µg/ml) against the pandemic virus. In a competition ELISA, MA2077 competed with the binding site of the human MAb, 2D1 (isolated from a survivor of the 1918 Spanish flu pandemic) on pandemic H1N1 HA. Epitope mapping studies using yeast cell-surface display of a stable HA1 fragment, wherein 'Sa' and 'Sb' sites were independently mutated, localized the binding site of MA2077 within the 'Sa' antigenic site. These studies will facilitate our understanding of antigen antibody interaction in the context of neutralization of the pandemic influenza virus.
authors: Reproductive Cell Biology Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
authors: Nachiket
authors: N
authors: Shembekar
authors: Vamsee V Aditya
authors: VV
authors: Mallajosyula
authors: Arpita
authors: A
authors: Mishra
authors: Leena
authors: L
authors: Yeolekar
authors: Rajeev
authors: R
authors: Dhere
authors: Subhash
authors: S
authors: Kapre
authors: Raghavan
authors: R
authors: Varadarajan
authors: Satish Kumar
authors: SK
authors: Gupta
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology*; D000914:Antibodies, Viral / Q000276:immunology*; D000915:Antibody Affinity / Q000276:immunology; D000956:Antigens, Viral / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D002460:Cell Line; D061505:Cell Surface Display Techniques; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D005260:Female; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D051379:Mice; D008958:Models, Molecular; D011485:Protein Binding / Q000276:immunology; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs / Q000276:immunology
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D019267:Hemagglutinin Glycoproteins, Influenza Virus
references: Protein Eng Des Sel. 2007 Feb;20(2):81-90
references: 17242026
references: Proc Natl Acad Sci U S A. 1999 Feb 16;96(4):1164-6
references: 9989993
references: Biol Reprod. 2000 Jan;62(1):67-75
references: 10611069
references: Science. 2010 Apr 16;328(5976):357-60
references: 20339031
references: Science. 2011 Aug 12;333(6044):850-6
references: 21798894
references: Biochemistry. 2011 Sep 20;50(37):7891-900
references: 21827143
references: Cell. 1982 Dec;31(2 Pt 1):417-27
references: 6186384
references: Nature. 2009 Jun 25;459(7250):1122-5
references: 19516283
references: Nat Protoc. 2007;2(1):31-4
references: 17401334
references: J Mol Biol. 1971 Feb 14;55(3):379-400
references: 5551392
references: Annu Rev Microbiol. 1983;37:529-49
references: 6357060
references: PLoS One. 2010 Feb 08;5(2):e9106
references: 20161706
references: J Immunol Methods. 2004 Apr;287(1-2):147-58
references: 15099763
references: J Virol. 2011 Jan;85(2):865-72
references: 21068239
references: N Engl J Med. 2009 Nov 12;361(20):1945-52
references: 19745214
references: Science. 2004 Mar 19;303(5665):1866-70
references: 14764887
references: J Virol Methods. 2012 Jul;183(1):25-33
references: 22575685
references: PLoS Pathog. 2010 Jan 29;6(1):e1000745
references: 20126449
references: PLoS One. 2010 Jul 12;5(7):e11548
references: 20634959
references: Intervirology. 1987;27(4):205-17
references: 2447032
references: Methods Enzymol. 2000;328:430-44
references: 11075358
references: J Biol Chem. 2010 Aug 27;285(35):27100-27110
references: 20558728
references: J Virol. 2010 Mar;84(6):3127-30
references: 20042511
references: Virology. 1981 Aug;113(1):64-72
references: 6791373
references: Biochem Biophys Res Commun. 2011 Jun 3;409(2):253-9
references: 21569761
references: Proc Natl Acad Sci U S A. 2010 Aug 3;107(31):13701-6
references: 20615991
references: Virus Res. 2012 Jun;166(1-2):61-7
references: 22459010
references: New Microbiol. 2009 Oct;32(4):319-24
references: 20128437
references: mBio. 2012 May 29;3(3):
references: 22647789