Targeting of antigen to DC-SIGN enhances its immunogenicity. (A) iDCs were incubated with medium, 5 μg/mL KLH, or 5 μg/mL hD1-KLH for one hour at 37°C. Subsequently, iDCs were washed and cocultured with autologous KLH-responsive PBLs, derived from patients enrolled in the vaccination trial. After 4 days, cellular responses were assessed in a proliferation assay. Data are mean proliferation indices relative to medium control for experiments performed in triplicate ± SD. (B) Experiment performed as described in panel A, except that antigen-treated iDCs were matured with LPS before addition of PBLs.