C. Ginzkey: S. Eicker: J. Krause:H.-H. Hugo:M. Mehdorn:

# The Author(s) 2012. This article is published with open access at Springerlink.com Background Vaccination against tumour-associated anti-gens is one approach to elicit anti-tumour responses. We investigated the effect of polynucleotide (DNA) vaccination using a model antigen (E. coli lacZ) in a syngeneic gliosar-coma model (9L). Methods Fisher 344 rats were vaccinated thrice by intra-muscular injection of a lacZ-encoding or a control plasmid in weekly intervals. One week after the last vaccination, lacZ-expressing 9L cells were implanted into the striatum. Results After 3 weeks, in lacZ-vaccinated animals the tumours were significantly smaller than in control-vaccinated animals. In cytotoxic T cell assays lysis rates of>50 % could only be observed in a few of the lacZ-vaccinated animals. This response was directed agains