Figure 6: MAIT TCR affinity for MR1 bound to antigens.

SPR affinity-based measurements (at 25 °C) of the MAIT TCR binding to a potent agonist, rRL-6-CH₂OH. Saturation binding curves as determined by SPR for wild-type MAIT TCR (a) or MAIT TCR^Y95F TCR (b). Data are representative of two independent experiments with error bars representing s.e.m. of the duplicates. (c) Activation of SKW-MAIT-TRBV6-1 cells with rRL-6-CH₂OH. SKW cells transduced with genes encoding a MAIT TCR expressing wild-type or mutants Y95A, or Y95F invariant TCR α-chain (TRAV1–2–TRAJ33) paired with a TRBV6-1 β-chain were co-incubated with C1R antigen-presenting cells to which nil, or 15.2, 1.52, 0.152 or 0.0152 μM rRL-6-CH₂OH was added. After 18 h SKW cells were stained and analysed by flow cytometry for cell-surface expression of CD69. Shown is the mean fluorescence intensity of staining of CD69-APC on the Y-axis. Control SKW cells expressing the EBV-specific αβ TCR LC13 (ref. 40) were not activated by rRL-6-CH₂OH. Data are representative of two independent experiments with error bars representing the s.e.m. of triplicate samples.