Fig. 5

Nonstimulatory pMHC can enhance T-cell activation when CD8 binding to antigenic pMHCI is abrogated. sc GAG-HLA-A2 constructs were transfected into the T-REx CHO clone that could express low amount sc E183-HLA-A2 bearing D227K,T228A (a) or A245V (b) mutation. Single cell clones were sorted. Indicated T-REx CHO clones were co-cultured with human E183 CTL for 3 h. Cytokine production (TNF and IFN-γ) and upregulation of the degranulation marker CD107a were assessed by antibody staining and flow cytometry. Statistical significance was determined by using unpaired two-sided Student’s t test and shown as mean ± s.d. (ns nonsignificant, *p < 0.05, ^**p < 0.01, ^***p < 0.001, ^****p < 0.0001). Data are representative of three independent experiments. MFI mean fluorescence level