![TCR-017 and -018 recognize the same core epitope, S870–878, presented on DRB1*15:01.(A) Cells expressing TCR-017 or TCR-018 were left unstimulated or stimulated with 10 μg/ml recombinant S protein, 1 μg/ml S protein peptide pool, or 1 μg/ml MN peptide pool in the presence of autologous APCs and analyzed for GFP and CD69 expression. (B–D) Cells expressing TCR-017 or TCR-018 were stimulated with 0.3 μg/ml S peptide pool #1, #2, or selected S pool (S304–338, 421–475, 492–519, 683–707, 741–770, 785–802, 885–1273; B), 1 μg/ml S peptide pool #2 in the presence of HEK293T cells expressing the indicated HLAs (C), or 1 μg/ml single peptides S828–846 or S864–882 (D). (E) Sensitivity of TCR-017 and TCR-018 to the S864–882 epitope. TCR transfectants were stimulated with the indicated concentrations of S864–882 peptide and APCs from donor Ts-018. Activities are shown as percentages of the maximum responses induced by plate-coated anti-CD3 mAb. Data are shown as mean ± SD of triplicates. (F) Determination of the core epitope recognized by TCR-017 and TCR-018 (shown in red). Cells were stimulated with 1 μg/ml of serial overlapping 15-mer peptides covering the S861–887 region. Data are shown as mean ± SD of triplicates. (G and H) Occurrence of TCRα-017/018 (CDR3, CVVNRGSSYKLIF) and TCRβ-017/018 (CDR3, CASS[Q or P]TYEQYF) in a prepandemic healthy cohort from Japan (n = 27; G) and in cohorts of prepandemic healthy donors (n = 786) and convalescent COVID-19 patients (n = 1,413) from multiple ethnicities (H). Numbers of individuals possessing the TCRs among cohorts are indicated. Data are representative of two independent experiments (A–D and F), or four independent experiments (E). pep, peptide; Unstim, unstimulated.](https://cdn.rupress.org/rup/content_public/journal/jem/218/12/10.1084_jem.20211327/3/jem_20211327_fig2.png?Expires=1769069312&Signature=AW0xy2~lG~HR1zdLO5ngoSMAcvu588brXIkuCXv08zRt1RUERBluJXMpXWJhsrKpzPwmyT1Wn9ToNGcI~rTKXCaDWWoSxpfKDL76O3VYoqDfAzFwksjxwZRqvJmTh~DpoML-nlhMvvzoMOihFF4p3FZm0gPZiIoE6T~qZ3dzBKRk9hm1YO7YKteeHCn4q8urWejRKsYoam7H7jNYNf8OplkkFJdTpkmGYLQyyd~9Uf5M6j676epit05qSZJK2dQEltcCl~~3vnQT9ENgWrje8nzVSPCwTkg7A6vjFM2xH~yCHrfu5maP8ITljZFnf-K9ufFuPzObVSdZ7~fZ2TpIwA__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
TCR-017 and -018 recognize the same core epitope, S870–878, presented on DRB1*15:01. (A) Cells expressing TCR-017 or TCR-018 were left unstimulated or stimulated with 10 μg/ml recombinant S protein, 1 μg/ml S protein peptide pool, or 1 μg/ml MN peptide pool in the presence of autologous APCs and analyzed for GFP and CD69 expression. (B–D) Cells expressing TCR-017 or TCR-018 were stimulated with 0.3 μg/ml S peptide pool #1, #2, or selected S pool (S304–338, 421–475, 492–519, 683–707, 741–770, 785–802, 885–1273; B), 1 μg/ml S peptide pool #2 in the presence of HEK293T cells expressing the indicated HLAs (C), or 1 μg/ml single peptides S828–846 or S864–882 (D). (E) Sensitivity of TCR-017 and TCR-018 to the S864–882 epitope. TCR transfectants were stimulated with the indicated concentrations of S864–882 peptide and APCs from donor Ts-018. Activities are shown as percentages of the maximum responses induced by plate-coated anti-CD3 mAb. Data are shown as mean ± SD of triplicates. (F) Determination of the core epitope recognized by TCR-017 and TCR-018 (shown in red). Cells were stimulated with 1 μg/ml of serial overlapping 15-mer peptides covering the S861–887 region. Data are shown as mean ± SD of triplicates. (G and H) Occurrence of TCRα-017/018 (CDR3, CVVNRGSSYKLIF) and TCRβ-017/018 (CDR3, CASS[Q or P]TYEQYF) in a prepandemic healthy cohort from Japan (n = 27; G) and in cohorts of prepandemic healthy donors (n = 786) and convalescent COVID-19 patients (n = 1,413) from multiple ethnicities (H). Numbers of individuals possessing the TCRs among cohorts are indicated. Data are representative of two independent experiments (A–D and F), or four independent experiments (E). pep, peptide; Unstim, unstimulated.