B7-H3 specific T cells with chimeric antigen receptor and decoy PD-1 receptors eradicate established solid human tumors in mouse models

• Main Authors: Baozhu Huang, Liqun Luo, Jun Wang, Bailin He, Rui Feng, Na Xian, Qiong Zhang, Lieping Chen, Gangxiong Huang
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2020-01-01
• Series: OncoImmunology
• Subjects: b7-h3; car-t cells; pd-1; il-7r; cancer immunotherapy
• Online Access: http://dx.doi.org/10.1080/2162402X.2019.1684127

The application of chimeric antigen receptor (CAR)-T cell therapy in patients with advanced solid tumors remains a significant challenge. Simultaneously targeting antigen and the solid tumor microenvironment are two major factors that greatly impact CAR-T cell therapy outcomes. In this study, we engineered CAR-T cells to specifically target B7-H3, a protein commonly found in solid human tumors, using a single-chain variable fragment (scFv) derived from an anti-B7-H3 monoclonal antibody. We tested the antitumor activity of B7-H3 CAR-T cells in mouse models with solid human tumors and determined that B7-H3 CAR-T cells exhibited potent antitumor activity against B7-H3+ tumor cells in vitro and in vivo. In addition, PD-1 decoy receptors were engineered to include extracellular PD-1 fused to the intracellular stimulatory domain of either CD28 or IL-7 receptor, respectively, which were then introduced into B7-H3 CAR-T cells. As a result, these newly modified, superior CAR-T cells exhibited more persistent antitumor activity in B7-H3+/B7-H1+ tumors in vivo. Our findings indicate that B7-H3 specific CAR-T cells have the potential to treat multiple types of advanced solid tumors.