title: Dendritic cells and HIV-specific CD4+ T cells: HIV antigen presentation, T-cell activation, and viral transfer.
abstract: Human immunodeficiency virus (HIV)-specific CD4+ lymphocytes are preferentially infected in HIV-positive individuals. To study this preferential infection, we have derived several HIV-specific (HS) CD4+ clones. We show that in dendritic cells (DCs), HIV virion capture led to major histocompatibility complex class-II (MHC-II)-restricted viral antigen presentation and to activation of HS cells. In contrast, neither cell-free virions nor infected lymphocytes activated HS cells. In DCs, the dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN/CD209), which internalizes virions, promoted MHC-II presentation of HIV antigens. Activation of HS cells by HIV-exposed DCs triggered an efficient viral spread in lymphocytes. CD4+ clones with irrelevant antigenic specificities were not activated by HIV-exposed DCs and poorly supported viral replication under this setting. Our results unravel the mechanisms of MHC-II-restricted HIV antigen presentation by DCs and describe how HIV gains access to the very cells designed by the immune system to counteract this pathogen.
authors: Groupe Virus et Immunité, Unité de Recherche Associée (URA) Centre National de la Recherche Scientifique (CNRS) 1930, Paris, France.
authors: Arnaud
authors: A
authors: Moris
authors: Anthony
authors: A
authors: Pajot
authors: Fabien
authors: F
authors: Blanchet
authors: Florence
authors: F
authors: Guivel-Benhassine
authors: Margarita
authors: M
authors: Salcedo
authors: Olivier
authors: O
authors: Schwartz