DC-SIGN promotes exogenous MHC-I-restricted HIV-1 antigen presentation

Blood. 2004 Apr 1;103(7):2648-54. doi: 10.1182/blood-2003-07-2532. Epub 2003 Oct 23.

Abstract

Dendritic cells (DCs) facilitate HIV-1 spread in the host by capturing virions and transferring them to permissive lymphocytes in lymphoid organs. Lectins such as DC-specific ICAM-grabbing non-integrin (DC-SIGN) are involved in HIV-1 uptake by DCs, through high-affinity binding to viral envelope glycoproteins. We examined the role of DC-SIGN on the fate of incoming virions and on major histocompatibility complex class I (MHC-I)-restricted HIV-1 antigen presentation. We show that DC-SIGN expression in B-cell lines dramatically enhances viral internalization. In these cells, and also in primary DCs, most of the captured virions are rapidly degraded, likely in a lysosomal compartment. In addition, a fraction of incoming viral material is processed by the proteasome, leading to activation of anti-HIV-specific cytotoxic T lymphocytes (CTLs) by DC-SIGN-expressing cells. In DCs, DC-SIGN is not the only receptor involved, and redundant pathways of virus capture leading to antigen presentation likely coexist. Altogether, our results highlight new aspects of DC-SIGN interactions with HIV-1. The lectin does not significantly protect captured virions against degradation and promotes MHC-I exogenous presentation of HIV-1 antigens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigen Presentation / immunology*
  • Antigens, CD / immunology
  • CD4 Antigens / immunology
  • Cell Adhesion Molecules / immunology*
  • Dendritic Cells / cytology
  • Dendritic Cells / immunology*
  • HIV Antigens / immunology*
  • HIV Core Protein p24 / immunology
  • HIV-1 / immunology*
  • HLA-A2 Antigen / immunology
  • Histocompatibility Antigens Class I / immunology*
  • Humans
  • Lectins, C-Type / immunology*
  • Major Histocompatibility Complex
  • Receptors, Cell Surface / immunology*
  • Virion / immunology

Substances

  • Antigens, CD
  • CD4 Antigens
  • Cell Adhesion Molecules
  • DC-specific ICAM-3 grabbing nonintegrin
  • HIV Antigens
  • HIV Core Protein p24
  • HLA-A2 Antigen
  • Histocompatibility Antigens Class I
  • Lectins, C-Type
  • Receptors, Cell Surface