Tumor Gene Therapy Made Easy: Allogeneic Major Histocompatibility Complex in the C6 Rat Glioma Model

The C6 glioma in the immune-competent rat is a frequently used model in brain tumor gene therapy research. It displays the histologic hallmarks of the human glioblastoma and has been employed to demonstrate new mechanisms of anti-tumor immunity and therapeutic strategies. We noted that C6 tumors regressed sponta- neously in three of five animals and that protective anti-tumor immunity ensued without therapeutic inter- vention. A review of the literature revealed that different rat strains are used as "syngeneic" host for the C6 cell glioma, namely, BDIX, BDX, Sprague-Dawley, and Wistar. Allelotyping of the RT1.A (rat MHC I ho- molog) by a serologic technique and of the RT1.B (rat MHC II homolog) by a newly developed molecular technique showed that C6 cells express the haplotype RT1u and are allogeneic in the preceding rat strains. Expression of the gene encoding the transactivator CIITA in C6 gliomas using an EBV-based transduction system led to induction of MHC I and II and thereby mimicked therapeutic r...