Induction of immunogenicity after irradiation of renal carcinoma cell lines.

417 Background: Cellular vaccine therapy in RCC has shown disappointing clinical and immunologic results. Poor immunogenicity of tumor associated antigens (TAAs) and their restricted expression may account for a lack of antigen-specific T cell responses. Irradiation induces TAA expression and enhances the immunogenicity of tumor cells. We investigated the influence of irradiation on the immunogenicity of RCC tumor cells. Methods: Six (ACHN, 786-0, 769-P, Caki-1, A-498, A-704) commercially available RCC cell lines were cultured and subsequently exposed to 0, 12, or 16 Gy of ionizing radiation. Alive cells and supernatant were isolated at 2, 24, and 48 hours after irradiation. The TAA expression (CA9, 5T4, MUC-1, NY-ESO-1, HSP-70) was assessed using flow cytometry. Expression relative to control (ERC) was calculated. Cytokine analysis was performed using a 9-plex Luminex human cytokine assay and reported as the mean concentration of all cell lines. Results: CA9, 5T4, and NY-ESO-1 demonstrated a marked incre...