Dendritic cell (DC)-specific ICAM-3 grabbing nonintegrin (DC-SIGN) is a DC-specific antigen that plays an important role in the induction of primary immune responses as well as during HIV infection. In the present study, we analyzed the effect of binding of monoclonal antibody DCN46 to DC surface, expressed DC-SIGN on DC function. DC-SIGN antibody treated, immature DC were able to differentiate into mature DC and had the same capacity as untreated DC to induce primary and secondary immune responses. In combination with flow cytometric cell sorting, DC-SIGN antibody treatment of DC yielded highly pure and functional DC. Given the apparent lack of functional effect of monoclonal antibody DCN46 on DC, the latter antibody may prove useful for research on and clinical use of highly pure and functional DC.