TCR-engineered T cells targeting a shared β-catenin mutation eradicate solid tumors
Maria Stadheim Eggebø, Julia Heinzelbecker, Heyilimu Palashati, Nicholas Chandler, Trung Tran, Yingqian Li, Weiwen Yang, Maarja Laos, Isaac Blaas, Even H Rustad, Ravi Chand Bollineni, Marina Delić-Šarac, Fridtjof Lund‐Johansen, Morten M. Nielsen, Johanna Olweus
Abstract
HLA-bound peptides encoded by recurrent driver mutations are candidate targets for T cell-directed immunotherapy. Here we identify two neopeptides encoded by the CTNNB1S37F mutation presented on the frequent HLA-A*02:01 and HLA-A*24:02 molecules in cell lines naturally expressing the mutation and HLA alleles. This mutation leads to a gain of function in β-catenin and is estimated to occur in >7,000 new cancer cases annually in the United States. T cell receptors (TCRs) that specifically recognize the mutant peptides were isolated from naive healthy donor T cells. T cells redirected with CTNNB1-S37F TCRs efficiently killed CTNNB1S37F+ cell lines and patient-derived organoids in vitro and eradicated established tumors in a melanoma cell line mouse model and a patient-derived xenograft model of endometrial adenocarcinoma naturally expressing the mutation and the restricting HLA. We propose that TCR-T cells targeting CTNNB1-S37F can serve as a basis for solid cancer immunotherapy. TCR-T cells are T cells engineered to express a specific T cell receptor. Here the authors present a TCR-T cell that targets CTNNB1-S37F, corresponding to a shared cancer driver mutation. This immunotherapy killed solid tumors when applied to a patient-derived xenograft model in mice.