OncoTargets and Therapy (Nov 2019)
CD137 Co-Stimulation Improves The Antitumor Effect Of LMP1-Specific Chimeric Antigen Receptor T Cells In Vitro And In Vivo
Abstract
Xiaojun Tang,1,2,* Qi Tang,1,3,* Yuan Mao,4 Xiaochen Huang,1,3 Lizhou Jia,1,3 Jin Zhu,5 Zhenqing Feng1,3,6,6 1NHC Key Laboratory of Antibody Technique, Nanjing Medical University, Nanjing, People’s Republic of China; 2Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, People’s Republic of China; 3Department of Pathology, Nanjing Medical University, Nanjing, People’s Republic of China; 4Department of Haematology and Oncology, Geriatric Hospital of Nanjing Medical University, Nanjing, People’s Republic of China; 5Huadong Medical Institute of Biotechniques, Nanjing, People’s Republic of China; 6Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Zhenqing FengNHC Key Laboratory of Antibody Technique, Department of Pathology, Jiangsu Key Laboratory of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, People’s Republic of ChinaEmail [email protected]: In previous research, we have found that LMP1-specific chimeric antigen (HELA/CAR) T cells can specifically recognize and kill LMP1-positive NPC cells. However, the tumor-inhibitory effectiveness of HELA/CART cells needs to be enhanced.Methods: We created two CARs that contain the T cell receptor-ζ (TCR-ζ) signal transduction domain with the CD28 and CD137 (4-1BB) or CD134 (OX-40) intracellular domains in tandem (HELA/137CAR or HELA/134CAR). Then, the tumor-inhibitory functions of two new CAR-T cells were investigated, both in vitro and in vivo.Results: The results showed that, after short-term expansion, primary human T cells were subjected to lentiviral gene transfer, resulting in large numbers of cells with >80% CAR expression. All CART cells were effective in killing SUNE1-LMP1 and C1R-neo cells, while HELA/137CART cells produced greater quantities of IFN-γ and IL-2 than HELA/CART cells. However, the level of IL-2 not INF-γ secreted by HELA/134CART cells was increased under the stimulation of LMP1 antigen. In an LMP1-positive NPC mouse xenograft model, HELA/137CART cells exhibited better antitumor activity and longer survival time in vivo compared with HELA/CAR T cells.Conclusion: The findings suggest that CD137 and CD28 is a better costimulatory signaling domain than CD28 only for optimizing tumor-inhibitory roles.Keywords: chimeric antigen receptors, LMP1, EBV, CD137
