Extended Data Fig. 2: Identification of HLA-A2- and HLA-A24-bound CTNNB1S37F-encoded peptides detected from both minigene-transduced and naturally mutated cell lines.
From: TCR-engineered T cells targeting a shared β-catenin mutation eradicate solid tumors
a, Mass to charge (m/z) ratio spectra of CTNNB1-S37F peptides eluted from HLA-A*02:01+ or HLA-A*24:02+ B721.221 cell lines transduced with a minigene containing the CTNNB1S37F mutation. b, Overview of natural and introduced expression of HLA-A*02:01 and HLA-A*24:02 in Mel888A24+A2 and Hutu80A2+A24 cell lines. c, d, Mirror image plots comparing the fragmentation pattern of endogenous CTNNB1-S37F and CTNNB1-WT peptides (blue) eluted from the two cell lines (c) Mel888A24+A2 and (d) Hutu80A2+A24, as compared to their isotopically labelled counterparts (pink). e, Representative retention time images showing targeted quantification analysis of CTNNB1-S37F and corresponding CTNNB1-WT peptides eluted from HLA-A*02:01 and HLA-A*24:02 of Mel888A24+A2 and Hutu80A2+A24 cell lines compared with their cognate spike-in standard peptides. Data shown from one experiment is representative of n = 3 individual experiments. Transition masses listed in Supplementary Table 1. f, Expression levels of HLA-A*02:01 (left) and HLA-A*24:02 (right) in Mel888A24+A2 and Hutu80A2+A24 transduced to express these alleles, as compared to a selection of naturally HLA-A*02:01- and HLA-A*24:02-expressing cell lines. The peak to the left represents background fluorescence whereas the peak to the right shows anti-HLA-staining for each cell line. g, Off-rates for CTNNB1-S37F and CTNNB1-WT peptides binding to HLA-A*02:01 or HLA-A*24:02 coupled to fluorescent particles, assessed by flow cytometry. Each datapoint represents mean fluorescence intensity (MFI) values at indicated timepoints (hours), reflecting the amount of intact pMHC complexes per particle. Vertical lines indicate calculated half-lives. Data shown for one experiment is representative of n = 3 independent experiments with one technical replicate per experiment, and each data point represents one technical replicate.
