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

A Moris, C Nobile, F Buseyne, F Porrot, JP Abastado… - Blood, 2004 - ashpublications.org
A Moris, C Nobile, F Buseyne, F Porrot, JP Abastado, O Schwartz
Blood, 2004ashpublications.org
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 …
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.
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