Production of Antibodies against Multipass Membrane Proteins Expressed in Human Tumor Cells Using Dendritic Cell Immunization

Antibody mediated therapeutic strategies against human malignant tumors have been widely authorized and clinically applied to cancer patients. In order to develop methods to generate antibodies reactive to the extracellular domains of multipass plasma membrane proteins specifically expressed in malignant tumors, we examined the use of dendritic cells (DCs) for immunization. DCs were transduced with genes encoding the human six transmembrane epithelial antigen of prostate 1 (STEAP1), STEAP4, and seven transmembrane prostate specific G-protein coupled receptor (PSGR). Mice were immunized with these DCs and followed by repeated booster immunization with plasmids expressing each protein. The immunized mice produced significant amounts of antibodies against these proteins. Our results suggest that DC immunization is an effective method to produce antibodies reactive to extracellular regions of plasma membrane proteins with multiple-transmembrane domains, and may be useful to develop antibody mediated antitumor therapies.