Transgenic rodent models of prostate cancer have served as valuable preclinical 
models to evaluate novel treatments and understand malignant disease 
progression. In particular, a transgenic rat autochthonous model of prostate 
cancer using the SV40 large T antigen expressed under a prostate-specific 
probasin promoter was previously developed as a model of androgen-dependent 
prostate cancer (TRAP). In the current report, we backcrossed this strain to the 
Lewis strain, an inbred rat strain better characterized for immunological 
analyses. We demonstrate that Lewis transgenic rats (Lew-TRAP) developed 
prostate adenocarcinomas with 100% penetrance by 25 weeks of age. Tumors were 
predominantly androgen-dependent, as castration prevented tumor growth in the 
majority of animals. Finally, we demonstrate that Lew-TRAP rats could be 
immunized with a DNA vaccine encoding a human prostate tumor antigen (prostatic 
acid phosphatase) with the development of Lewis strain-specific T-cell 
responses. We propose that this Lew-TRAP strain, and prostate tumor cell lines 
derived from this strain, can be used as a future prostate cancer immunotherapy 
model.