Table of Contents
Volume 2012, Article ID 823605, 9 pages
Research Article

Conservation, Compensation, and Evolution of N-Linked Glycans in the HIV-1 Group M Subtypes and Circulating Recombinant Forms

Medical Research Council Unit for Bioinformatics Capacity Development, South African National Bioinformatics Institute, University of the Western Cape, Private Bag X17, Belville 7535, South Africa

Received 18 October 2012; Accepted 25 November 2012

Academic Editors: Z. Banki and M. Gherardi

Copyright © 2012 Simon A. Travers. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The “glycan shield” exposed on the surface of the HIV-1 gp120 env glycoprotein has been previously proposed as a novel target for anti-HIV treatments. While such targeting of these glycans provides an exciting prospect for HIV treatment, little is known about the conservation and variability of glycosylation patterns within and between the various HIV-1 group M subtypes and circulating recombinant forms. Here, we present evidence of strong strain-specific glycosylation patterns and show that the epitope for the 2G12 neutralising antibody is poorly conserved across HIV-1 group M. The unique glycosylation patterns within the HIV-1 group M subtypes and CRFs appear to explain their varying susceptibility to neutralisation by broadly cross-neutralising (BCN) antibodies. Compensatory glycosylation at linearly distant yet three-dimensionally proximal amino acid positions appears to maintain the integrity of the glycan shield while conveying resistance to neutralisation by BCN antibodies. We find that highly conserved clusters of glycosylated residues do exist on the gp120 trimer surface and suggest that these positions may provide an exciting target for the development of BCN anticarbohydrate therapies.