Reconstitution of HLA-DR expression by transduction and gene repair. (A) Staining for HLA-DR expression of Raji WT cells as positive control, Raji DRB knockout cells (DRB^−/−) treated with sgRNA, and a nonspecific DNA oligomer and DRB^−/− cells treated with sgRNA and specific DNA oligo with sequences homologous to target site (DRB^−/− gene repair). (B) GFP fluorescence of JE6.1 reporter cells expressing the respective γδ TCRs with either Raji WT, Raji RFXAP knockout cells (RFXAP^−/−) or RFXAP^−/− transduced with HLA-DRA and indicated HLA-DRB. Statistical test: two-way ANOVA with Tukey’s multiple comparisons test; ****, P < 0.0001 (n = 3, error bars = SD of mean).