LAUSR

T cells mediate a broad range of immune responses, especially generation of adaptive immunity for cancer cell clearance. Identification of genetic components that modulate T cell proliferation, differentiation, migration and cytotoxicity would facilitate development of more effective cancer immunotherapy. CRISPR/Cas9, as a tool, could generate gene knockout with high specificity and efficiency and has been widely used in genome-wide screening for therapeutic targets in many tumor cell models. However, its application to primary cells especially T cell has not been extensively investigated. Here, we described how to employ the CRISPR/Cas9 tools for immune-oncology target identification in primary mouse T cells. Cas9/sgRNA could be transduced into T cells with high efficiency and low toxicity using a lentivirus based delivery system. The transduced T cells acquired Cas9 expression but no DNA editing was observed. However, we achieved gene editing in primary T cells isolated from a Cas9 transgenic mouse strain after lentiviral delivery of guide RNA9s. In summary, we provide a new method to generate DNA editing in primary T cell using CRISPR/Cas9 technology. It could be used for gene knockout, knockin and even genome-wide screening in primary T cell for immune checkpoint regulators. Citation Format: Xi Li, Wanbing Tang, Chenjie Zhou, Yulin Yang, Zhengang Peng, Wenrong Zhou, Qunsheng Ji, Yong Cang. Application of CRISPR/Cas9 gene editing to primary T cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 785.