517. Anti-Tumor Immunity Is Elicited by a Conditionally Replicative Adenovirus in Canine Osteosarcoma

Abstract

S206 high titer (1,000vp/cell) in an in vitro assay. To look at the efficacy of the O-Ad and CART combination, we performed a killing assay. O-Ad clearly enhanced killing by CART cells in luciferase based assay. We also used xCELLigence real time cell analyzer (RTCA) for kinetic analysis of killing. In combination with O-Ad, more rapid killing kinetics by CART cells were observed especially in lower E:T ratio. To look at the impact of the combination in vivo, subcutaneous ASPC1-CBG-GFP in NSG mice were treated with CART alone or in combination with intra-tumoral injection of O-Ad. O-Ad showed significant synergy with CART in luciferase based photon assay. And higher number of T cells was observed in spleen in the O-Ad armed with IL2 combination group. Conclusions: These results suggest that combination therapy of O-Ad armed with cytokine(s) and CART cells is effective against solid tumors by enhancing T cell activity.