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.