Vaccination with Her-2/neu DNA or protein subunits protects against growthof a Her-2/neu-expressing murine tumor

The present study utilizes an in vivo murine tumor expressing human Her-2/n eu to evaluate potential Her-2/neu vaccines consisting of either full lengt h or various subunits of Her-2/neu delivered in either protein or plasmid D NA form. Our results demonstrate that protective immunity against Her-2/neu -expressing tumor challenge can be achieved by vaccination with plasmid DNA encoding either full length or subunits of Her-2/neu. Partial protective i mmunity was also observed following vaccination with the intracellular doma in (ICD), but not extracellular domain (ECD), protein subunit of Her-2/neu. The mechanism of protection elicited by plasmid DNA vaccination appeared t o be exclusively CD4 dependent, whereas the protection observed with ICD pr otein vaccination required both CD4 and CD8 T cells. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.