Gene expression profile of regenerated CD8αα T cells and CD8αβ T cells from LMP2 T-iPSCs

Whereas cytotoxic T lymphocytes (CTLs) represent the most promising therapeutic avenue in cancer immunotherapy, adaptive transfer of antigen-specific CTLs has faced difficulty in efficient expansion of CTLs from patients in ex vivo culture. To solve this issue, several groups have proposed that the induced pluripotent stem cell (iPSC) technology can be applied for the expansion of antigen-specific CTLs: when iPSCs are produced from antigen-specific CTLs and CTLs are induced from these iPSCs, all regenerated CTLs express the same TCR as original CTLs. However, in these previous studies, one critical issue remains to be solved. With current methods, the regenerated CTLs are mostly of the CD8αα+ innate type and have less antigen-specific cytotoxic activity than primary CTLs. Here we report that, by stimulating purified iPSC-derived CD4/CD8 double positive (DP) cells with anti-CD3 antibody, T cells expressing CD8αβ were generated and they had cytotoxic activity comparable to primary CTLs.