Gene gun Her2/neu DNA vaccination: evaluation of vaccine efficacy in a syngeneic Her2/neu mouse tumor model

Genetic vaccination using naked plasmid DNA is an immunization strategy both against infectious diseases and cancer.In order to improve efficacy of DNA vaccines, particularly in large animals and humans, different strategies have been pursued. These vaccination strategies are based on different application routes, schedules and coexpression of immunomodulatory molecules as adjuvants. Our mouse tumor model offers the possibility to investigate Her2/neu DNA vaccines in different settings, that is, intramuscular or intradermal application with or without coexpression of adjuvants. The immunogenicity of predicted peptides for Her2/neu specific memory T cells were screened and confirmed after intramuscular and intradermal application. Protection from tumor growth in tumor challenge experiments and both T cell and humoral immune responses against Her2/neu peptides are used as surrogate parameters for vaccine efficacy.