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Proc Natl Acad Sci USA. Complex-type N-glycan recognition by potent broadly neutralizing HIV antibodies
[Source: Proceedings of the National Academy of the Sciences of the United States of America, full text: (LINK). Abstract, edited.]
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Complex-type N-glycan recognition by potent broadly neutralizing HIV antibodies
Hugo Mouquet<SUP>a</SUP>,<SUP>1</SUP>,<SUP>2</SUP>, Louise Scharf<SUP>b</SUP>,<SUP>1</SUP>,<SUP>2</SUP>, Zelda Euler<SUP>c</SUP>, Yan Liu<SUP>d</SUP>, Caroline Eden<SUP>a</SUP>, Johannes F. Scheid<SUP>a</SUP>,<SUP>e</SUP>, Ariel Halper-Stromberg<SUP>a</SUP>, Priyanthi N. P. Gnanapragasam<SUP>b</SUP>, Daniel I. R. Spencer<SUP>f</SUP>, Michael S. Seaman<SUP>g</SUP>, Hanneke Schuitemaker<SUP>c</SUP>, Ten Feizi<SUP>d</SUP>, Michel C. Nussenzweig<SUP>a</SUP>,<SUP>2</SUP>,<SUP>3</SUP>, and Pamela J. Bjorkman<SUP>b</SUP>,<SUP>2</SUP>,<SUP>3</SUP>
<SUP></SUP>
Author Affiliations: <SUP>a</SUP>Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10021; <SUP>b</SUP>Division of Biology, California Institute of Technology, Pasadena, CA 91125; <SUP>c</SUP>Department of Experimental Immunology, Academic Medical Center, 1105 AZ Amsterdam, The Netherlands; <SUP>d</SUP>Glycosciences Laboratory, Department of Medicine, Imperial College London, London, W12 0NN, United Kingdom; <SUP>e</SUP>Charit? Universit?tsmedizin, 10117 Berlin, Germany; <SUP>f</SUP>Ludger Ltd., Culham Science Centre, Abingdon, Oxfordshire OX14 3EB, United Kingdom; and <SUP>g</SUP>Beth Israel Deaconess Medical Center, Boston, MA 02215
Contributed by Pamela J. Bjorkman, October 4, 2012 (sent for review September 15, 2012)
Abstract
Broadly neutralizing HIV antibodies (bNAbs) can recognize carbohydrate-dependent epitopes on gp120. In contrast to previously characterized glycan-dependent bNAbs that recognize high-mannose N-glycans, PGT121 binds complex-type N-glycans in glycan microarrays. We isolated the B-cell clone encoding PGT121, which segregates into PGT121-like and 10-1074?like groups distinguished by sequence, binding affinity, carbohydrate recognition, and neutralizing activity. Group 10-1074 exhibits remarkable potency and breadth but no detectable binding to protein-free glycans. Crystal structures of unliganded PGT121, 10-1074, and their likely germ-line precursor reveal that differential carbohydrate recognition maps to a cleft between complementarity determining region (CDR)H2 and CDRH3. This cleft was occupied by a complex-type N-glycan in a ?liganded? PGT121 structure. Swapping glycan contact residues between PGT121 and 10-1074 confirmed their importance for neutralization. Although PGT121 binds complex-type N-glycans, PGT121 recognized high-mannose-only HIV envelopes in isolation and on virions. As HIV envelopes exhibit varying proportions of high-mannose- and complex-type N-glycans, these results suggest promiscuous carbohydrate interactions, an advantageous adaptation ensuring neutralization of all viruses within a given strain.
Footnotes
<SUP>1</SUP>H.M. and L.S. contributed equally to this work.
<SUP>2</SUP>To whom correspondence may be addressed. E-mail: hmouquet@rockefeller.edu, lscharf@caltech.edu, nussen@rockefeller.edu, or bjorkman@caltech.edu.
<SUP>3</SUP>M.C.N. and P.J.B. contributed equally to this work.
Author contributions: H.M and M.C.N conceived the project; H.M., L.S., Z.E., Y.L., H.S., T.F., M.C.N., and P.J.B. designed research; H.M., L.S., Z.E., Y.L., H.S., T.F., M.C.N., and P.J.B. performed research; H.M. produced the antibodies and the HIV Env proteins; H.M. performed and analyzed antibody-binding experiments; L.S. determined and interpreted crystal structures; C.E., J.F.S., and A.H.-S. contributed new reagents/analytic tools; Z.E. and H.S. performed and analyzed PBMC-based neutralization assays; Y.L. performed carbohydrate microarray analyses; P.N.P.G. performed and analyzed neutralization assays using viral strains produced in GnTI <SUP>−/−</SUP> cells; D.I.R.S. isolated and characterized the NA2 glycan; M.S.S. performed and analyzed TZM-bl neutralization assays; and H.M., L.S., Y.L., T.F., M.C.N., and P.J.B. wrote the paper.
Conflict of interest statement: M.C.N., H.M., P.J.B. and L.S. have a pending patent application for the new PGT121 antibody variants described in the present study with the United States Patent and Trademark Office.
Data deposition: The atomic coordinates and structure factors have been deposited in the Protein Data Bank, www.pdb.org [PDB ID codes 4FQ1 (unliganded PGT121 Fab), 4FQC (?liganded? PGT121 Fab), 4FQ2 (10-1074 Fab), and 4FQQ (GL Fab)].
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1217207109/-/DCSupplemental.
Freely available online through the PNAS open access option.
-<SUP></SUP>
Author Affiliations: <SUP>a</SUP>Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10021; <SUP>b</SUP>Division of Biology, California Institute of Technology, Pasadena, CA 91125; <SUP>c</SUP>Department of Experimental Immunology, Academic Medical Center, 1105 AZ Amsterdam, The Netherlands; <SUP>d</SUP>Glycosciences Laboratory, Department of Medicine, Imperial College London, London, W12 0NN, United Kingdom; <SUP>e</SUP>Charit? Universit?tsmedizin, 10117 Berlin, Germany; <SUP>f</SUP>Ludger Ltd., Culham Science Centre, Abingdon, Oxfordshire OX14 3EB, United Kingdom; and <SUP>g</SUP>Beth Israel Deaconess Medical Center, Boston, MA 02215
Contributed by Pamela J. Bjorkman, October 4, 2012 (sent for review September 15, 2012)
Abstract
Broadly neutralizing HIV antibodies (bNAbs) can recognize carbohydrate-dependent epitopes on gp120. In contrast to previously characterized glycan-dependent bNAbs that recognize high-mannose N-glycans, PGT121 binds complex-type N-glycans in glycan microarrays. We isolated the B-cell clone encoding PGT121, which segregates into PGT121-like and 10-1074?like groups distinguished by sequence, binding affinity, carbohydrate recognition, and neutralizing activity. Group 10-1074 exhibits remarkable potency and breadth but no detectable binding to protein-free glycans. Crystal structures of unliganded PGT121, 10-1074, and their likely germ-line precursor reveal that differential carbohydrate recognition maps to a cleft between complementarity determining region (CDR)H2 and CDRH3. This cleft was occupied by a complex-type N-glycan in a ?liganded? PGT121 structure. Swapping glycan contact residues between PGT121 and 10-1074 confirmed their importance for neutralization. Although PGT121 binds complex-type N-glycans, PGT121 recognized high-mannose-only HIV envelopes in isolation and on virions. As HIV envelopes exhibit varying proportions of high-mannose- and complex-type N-glycans, these results suggest promiscuous carbohydrate interactions, an advantageous adaptation ensuring neutralization of all viruses within a given strain.
Footnotes
<SUP>1</SUP>H.M. and L.S. contributed equally to this work.
<SUP>2</SUP>To whom correspondence may be addressed. E-mail: hmouquet@rockefeller.edu, lscharf@caltech.edu, nussen@rockefeller.edu, or bjorkman@caltech.edu.
<SUP>3</SUP>M.C.N. and P.J.B. contributed equally to this work.
Author contributions: H.M and M.C.N conceived the project; H.M., L.S., Z.E., Y.L., H.S., T.F., M.C.N., and P.J.B. designed research; H.M., L.S., Z.E., Y.L., H.S., T.F., M.C.N., and P.J.B. performed research; H.M. produced the antibodies and the HIV Env proteins; H.M. performed and analyzed antibody-binding experiments; L.S. determined and interpreted crystal structures; C.E., J.F.S., and A.H.-S. contributed new reagents/analytic tools; Z.E. and H.S. performed and analyzed PBMC-based neutralization assays; Y.L. performed carbohydrate microarray analyses; P.N.P.G. performed and analyzed neutralization assays using viral strains produced in GnTI <SUP>−/−</SUP> cells; D.I.R.S. isolated and characterized the NA2 glycan; M.S.S. performed and analyzed TZM-bl neutralization assays; and H.M., L.S., Y.L., T.F., M.C.N., and P.J.B. wrote the paper.
Conflict of interest statement: M.C.N., H.M., P.J.B. and L.S. have a pending patent application for the new PGT121 antibody variants described in the present study with the United States Patent and Trademark Office.
Data deposition: The atomic coordinates and structure factors have been deposited in the Protein Data Bank, www.pdb.org [PDB ID codes 4FQ1 (unliganded PGT121 Fab), 4FQC (?liganded? PGT121 Fab), 4FQ2 (10-1074 Fab), and 4FQQ (GL Fab)].
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1217207109/-/DCSupplemental.
Freely available online through the PNAS open access option.
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