FIG 3.

CD8⁺ T cell response against the endogenously processed epitope IPFYGKAI_1373–1380. Effector T cells were expanded for 10 days from PBMCs in the presence of the peptide IPFYGKAI. HLA-B*51-positive target cells were generated by electroporation with a NS3(aa1330-2420)-GFP fusion protein. GFP-positive cells were sorted and used as targets for restimulation of IPFYGKAI-specific effector CD8⁺ T cells in an effector/target ratio of 1:1 for 4 h, followed by an intracellular cytokine staining (ICS). Mock transfected targets and peptide-pulsed targets served as negative or positive controls, respectively. (A) Representative fluorescence-activated cell sorting results of one ICS. (B) The IFN-γ response against targets transfected with GT1a prototype NS3 was normalized to 100% and compared to the response against other targets as indicated. The data represent results from at least three independent experiments. The P values were calculated using a one-sample t test with a hypothetical value of 100 (S1368P versus pt1a) or an unpaired t test (pt GT3a versus S1369P).