[OE9] Oral English Session 9　Therapeutics / Next Generation Sequencing

[OE9-2] ネオ抗原特異的T細胞受容体遺伝子導入T細胞を用いた養子免疫療法の開発

^○住本 秀敏^1,2, 寺田 晃士³, 縣 保年³, 村田 聡², 醍醐 弥太郎^1,2,4 (1.滋賀医科大学 医学部 臨床腫瘍学講座, 2.滋賀医科大学附属病院 腫瘍センター, 3.滋賀医科大学 医学部 分子生理化学, 4.東京大学医科学研究所 抗体ワクチンセンター)

[Background] We have developed a new method to identify immunogenic neoantigens (NeoAgs) as well as the corresponding T cell receptor (TCR) β complementarity-determining region 3 (CDR3) sequences based on identification of Ag-specific clonal growth using next generation sequencing (NGS), that is more sensitive than ELISPOT by 100-fold. [Object] We attempted to make a platform for adaptive cancer immunotherapy with NeoAg-specific TCR-gene-transduced T cells using influenza peptide (Flu) Ag as a model. [Methods] HLA-A^*02:01-restricted Flu-specific T cell clones were single cell-sorted, and the TCRαβ cDNAs of each clone were sequenced. Flu- specific TCRαβ cDNAs-expressing PiggyBac (PB) and retroviral vector were constructed, which stably transduced the TCRαβ cDNAs into Jurkat and human primary CD8⁺T cells, respectively. The transduction efficiency and phenotypes of transduced CD8⁺T cells were evaluated by flow cytometry. [Results] Among 83 single cell-sorted CD8⁺T cell clones, 18 and 14 clones were identical, and their TCRβ CDR3 corresponded to those identified by NGS. PB vector successfully transduced the Flu-specific TCR αβ into Jurkat cells with an efficiency of 65.3％. Retroviral vector transduced the TCR genes into human primary CD8⁺T cells with an efficiency of 46.1±15.0％. Among CD3⁺CD8⁺Flu-Tetramer⁺ T cells, CD45RO⁺CCR7⁺ central memory T cells were 8.5±5.4％, while CD45RA⁺CCR7⁺ naive T cells were 6.2±4.5％. [Conclusion] Combination of this platform with PDX model could be an effective approach to promptly develop adaptive immunotherapies for human cancer.