Figure 1. Principle of targeting of antigens encoded by DNA vaccines to DCs.

The coding region of variable heavy (V_H) and light (V_L) chains of antibodies to uptake receptors of DCs are fused in frame to the open reading frame of the antigen. After delivery of the DNA vaccine, transduced cells of the immunized individual produce and secret a single chain antibody to the uptake receptor coupled to the antigen. Binding of the single chain to the uptake receptors should increase uptake and presentation of the antigen by the DCs.