Combination gene therapy of IL-12 and allogeneic MHC class I gene via stimulating NK cytolytic activity

In this study, we tested whether expressing an allogeneic MHC class I gene and/or a cytokine gene in tumor cells could induce anti-tumor immunity. We computed the potential therapeutic benefit of introducing IL-12 or H-2K(b) alone and in combination into CT26 tumor cells. Whereas IL-12 expression in CT26 cells delayed the formation of tumors, the expression of class I mole cules alone was apparently, insufficient to reduce tumorigenicity. The comb ined expression of IL-12 and H-2Kb, however, more efficiently reduced tumor growth than did either genes alone. Histological examination of tumors exp ressing IL-12 and H-2K(b) showed a non-specific inflammatory reaction, such as a necrosis, and an increased tissue infiltrate of immune effectors. The se results suggest that the combined expression of IL-12 and H-2K(b) in tum or cells has potential therapeutic benefit.