Retroviral-mediated IL-2 and IFN-γ gene transfer in human bladder tumor cells

Tumor cells may escape immune surveillance mainlyby (1) down regulation of major histocompatibilitycomplex (MHC) molecules or alteration of antigen-processing pathways; (2) low-level of cytokines in thevicinity of the tumor, which can’t activate immunosystemeffectively. Recent studies have shown that geneticallyengineered tumor cells expressing cytokines such as IL-2IFN-γ can induce greater CTL activity and activate NK,LAK and TIL. Besides IFN-γ can enhance the