FIG. 2.

Epitope-specific IFN-γ production by CTLs after stimulation with peptide-pulsed BLCL. The number of IFN-γ-producing cells per 10,000 CD8⁺ T cells (5,000 cells for subject 3) from subjects from HLA groups I (A), II (B), and III (C) were measured by ELISPOT assay. CD8⁺ T cells were isolated from PBMC populations expanded in vitro with influenza virus A/NL/18/94 and subsequently stimulated with peptide variants as indicated. (*, peptide sequence of the known human influenza virus CTL epitopes).