DC acquisition of allogeneic HLA class I from activated human lymphocytes.

DCs from an HLA-A2–negative individual were cocultivated with PHA-activated human lymphocytes expressing the HLA-A2 allele (right panels). As a control, DCs were cocultured with HLA-unrelated lymphocytes (left panels). After 20 hours, the expression of the allogeneic HLA molecules on the cell surface of the DC populations was analyzed by flow cytometry using mAbs specific for HLA-A2 and CD83 (upper panels) or CD1a (lower panels).