JVI Figure table search 04
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hong, P. W.-P.
Right arrow Articles by Lee, B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hong, P. W.-P.
Right arrow Articles by Lee, B.

 Previous Article  |  Next Article 

Journal of Virology, December 2002, p. 12855-12865, Vol. 76, No. 24
0022-538X/02/$04.00+0     DOI: 10.1128/JVI.76.24.12855-12865.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Human Immunodeficiency Virus Envelope (gp120) Binding to DC-SIGN and Primary Dendritic Cells Is Carbohydrate Dependent but Does Not Involve 2G12 or Cyanovirin Binding Sites: Implications for Structural Analyses of gp120-DC-SIGN Binding

Patrick W.-P. Hong,1 Karen B. Flummerfelt,1 Aymeric de Parseval,2 Kevin Gurney,1 John H. Elder,2 and Benhur Lee1,3,4*

Department of Microbiology, Immunology, and Molecular Genetics,1 Department of Pathology and Laboratory Medicine,3 UCLA AIDS Institute, University of California at Los Angeles School of Medicine, Los Angeles, California 90095,4 Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 920372

Received 5 June 2002/ Accepted 8 September 2002

The calcium-dependent lectin, DC-SIGN, binds to human immunodeficiency virus (HIV) (and simian immunodeficiency virus) gp120 and mediates the binding and transfer of HIV from monocyte-derived dendritic cells (MDDCs) to permissive T cells. However, it has been recently reported that DC-SIGN binding to HIV gp120 may be carbohydrate independent. Here, we formally demonstrate that gp120 binding to DC-SIGN and MDDCs is largely if not wholly carbohydrate dependent. Endo-ß-N-glucosaminidase H (EndoH) treatment of gp120-Fc under conditions that maintained wild-type CD4 binding—and the full complement of complex glycans—significantly decreased (>90%) binding to DC-SIGN expressing cell lines, as well as to MDDCs. Any residual binding of EndoH-treated gp120-Fc to DC-SIGN was completely competed off with mannan. Mutational analysis indicated that no single glycosylation site affected the ability of gp120-Fc to bind DC-SIGN. To further guide our efforts in mapping the DC-SIGN binding sites on gp120, we used two well-characterized HIV inhibitory agents (2G12 monoclonal antibody and cyanovirin) that bind to high-mannose sugars on gp120. We showed that 2G12 and DC-SIGN bound to nonoverlapping sites in gp120 because (i) 2G12 did not block soluble gp120 or virion binding to DC-SIGN, (ii) 2G12 bound to gp120-Fc that was prebound to cell surface DC-SIGN, and (iii) gp120-Fc mutants that lack glycosylation sites involved in 2G12's epitope were also fully capable of binding DC-SIGN. These data were substantiated by the inability of cyanovirin to block gp120-Fc binding to DC-SIGN. Cyanovirin has been shown to effectively compete for 2G12 binding to gp120. Indeed, high concentrations of cyanovirin dramatically enhanced gp120-Fc binding to cell surfaces in the presence or absence of DC-SIGN. We provide evidence that this enhancement may be due to cyanovirin's ability to bridge gp120 to mannosylated cell surface proteins. These results have implications for antiviral therapeutics and for ongoing efforts to finely map the glycan structures on gp120 responsible for DC-SIGN binding.

* Corresponding author. Mailing address: UCLA, Department of Microbiology, Immunology, and Molecular Genetics, 3825 MSB, 609 Charles E. Young Dr. East, Los Angeles, CA 90095. Phone: (310) 794-2132. Fax: (310) 267-2580. E-mail: benhurL{at}microbio.ucla.edu.

Journal of Virology, December 2002, p. 12855-12865, Vol. 76, No. 24
0022-538X/02/$04.00+0     DOI: 10.1128/JVI.76.24.12855-12865.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Mol. Cell. Biol. Microbiol. Mol. Biol. Rev.
Clin. Vaccine Immunol. ALL ASM JOURNALS

Copyright © 2002 by the American Society for Microbiology. All rights reserved.