HIV-1 N-glycan composition governs a balance between dendritic cell-mediated viral transmission and antigen presentation

J Immunol. 2011 Nov 1;187(9):4676-85. doi: 10.4049/jimmunol.1101876. Epub 2011 Sep 28.

Abstract

The natural function of dendritic cells (DCs) is to capture and degrade pathogens for Ag presentation. However, HIV-1 can evade viral degradation by DCs and hijack DCs for migration to susceptible CD4(+) T lymphocytes. It is unknown what factors decide whether a virus is degraded or transmitted to T cells. The interaction of DCs with HIV-1 involves C-type lectin receptors, such as DC-specific ICAM-3-grabbing nonintegrin, which bind to the envelope glycoprotein complex (Env), which is decorated heavily with N-linked glycans. We hypothesized that the saccharide composition of the Env N-glycans is involved in avoiding viral degradation and Ag presentation, as well as preserving infectious virus for the transmission to target cells. Therefore, we studied the fate of normally glycosylated virus versus oligomannose-enriched virus in DCs. Changing the heterogeneous N-linked glycan composition of Env to uniform oligomannose N-glycans increased the affinity of HIV-1 for DC-specific ICAM-3-grabbing nonintegrin and enhanced the capture of HIV-1 by immature DCs; however, it decreased the subsequent transmission to target cells. Oligomannose-enriched HIV-1 was directed more efficiently into the endocytic pathway, resulting in enhanced viral degradation and reduced virus transfer to target cells. Furthermore, Env containing exclusively oligomannose N-glycans was presented to Env-specific CD4(+) T cells more efficiently. Taken together, our results showed that the HIV-1 N-glycan composition plays a crucial role in the balance between DC-mediated Ag degradation and presentation and DC-mediated virus transmission to target cells. This finding may have implications for the early events in HIV-1 transmission and the induction of antiviral immune responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigen Presentation / immunology*
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / metabolism
  • Cell Adhesion Molecules / metabolism
  • Cell Line, Tumor
  • Coculture Techniques
  • Dendritic Cells / immunology*
  • Dendritic Cells / metabolism
  • Dendritic Cells / virology*
  • HEK293 Cells
  • HIV Envelope Protein gp120 / immunology
  • HIV Envelope Protein gp120 / metabolism
  • HIV Infections / immunology*
  • HIV Infections / metabolism
  • HIV Infections / transmission*
  • HIV-1 / immunology*
  • HIV-1 / metabolism
  • Humans
  • Lectins, C-Type / metabolism
  • Oligosaccharides / metabolism*
  • Polysaccharides / immunology
  • Polysaccharides / metabolism*
  • Receptors, Cell Surface / metabolism
  • Virion / immunology
  • Virion / metabolism
  • Virus Attachment

Substances

  • Cell Adhesion Molecules
  • DC-specific ICAM-3 grabbing nonintegrin
  • HIV Envelope Protein gp120
  • Lectins, C-Type
  • Oligosaccharides
  • Polysaccharides
  • Receptors, Cell Surface
  • oligomannoside