279. Eradication of Renal Cell Carcinoma in Mice Mediated by NK Cell Activation Using Inactivated Sendai Virus Particle (HVJ-E)

Conventional chemotherapy and radiation therapy have shown little antitumour activity against renal cell carcinoma (RCC). Although interleikin-2 or interferon ? treatment against RCC have shown some effectiveness (its response rate is approximately 20%), it is not satisfactory to us. Therefore, there is an urgent need to develop more effective therapy. UV inactivated Hemagglutinating virus of Japan envelope (HVJ-E; Sendai virus) has been developed as a safe non-viral vector and has been anticipated as a highly efficient delivery system because of its robust fusion activity. Recently, we have found that HVJ-E enhances interferon releasing from dendritic cells with the existence of murine renal cell carcinoma (Renca). By the injection of HVJ-E directly into Renca tumor mass, intradermal tumor mass was eradicated. Tumor-free mice generated by HVJ-E injection rejected Renca tumors when rechallenged. Therefore, HVJ-E appears to generate effective anti-tumor immunity. In this study, we investigated the mechanism of the generation of anti-tumor immunity by HVJ-E vector.