The C‐type lectin DC‐SIGN (CD209) is an antigen‐uptake receptor for Candida albicans on dendritic cells

Abstract

Dendritic cells (DC) that express the type II C‐type lectin DC‐SIGN (CD209) are located in the submucosa of tissues, where they mediate HIV‐1 entry. Interestingly, the pathogen Candida albicans,the major cause of hospital‐acquired fungal infections, penetrates at similar submucosal sites. Here we demonstrate that DC‐SIGN is able to bind C. albicans both in DC‐SIGN‐transfected cell lines and in human monocyte‐derived DC. The binding was shown to be time‐ as well as concentration‐dependent, and live as well as heat‐inactivated C. albicans were bound to the same extent. Moreover, in immature DC, DC‐SIGN was able to internalize C. albicans in specific DC‐SIGN‐enriched vesicles, distinct from those containing the mannose receptor, the other known C. albicans receptor expressed by DC. Together, these results demonstrate that DC‐SIGN is an exquisite pathogen‐uptake receptor that captures not only viruses but also fungi.