Antitumor vaccination with HER-2-derived recombinant antigens.

Certain types of malignant tumors overexpress HER-2, a transmembrane glycoprotein of the class I receptor tyrosine kinase erbB family. To develop an effective HER-2 vaccine for the selective immunotherapy of these malignancies, we have genetically engineered fusion proteins containing portions of extra- and intracellular HER-2 domains. Activated dendritic cells (DC) cocultured with these novel antigens (Ag) could induce potent responses of Ag-specific T-cell lines in vitro and a protection against HER-2-expressing tumor in vivo. The protective capabilities of HER-2-derived fusion proteins correlated with the efficiency of their presentation to Ag-specific T-cell hybridomas. The most effective Ag contained GM-CSF, the presence of which facilitated their internalization by antigen-presenting cells (APC) in a receptor-mediated manner. Copyright 2002 Wiley-Liss, Inc.