Fig. 1.
Specificity, avidity and function of HLA-A2-restricted, HER2-specific CTL clones. a Following expansion, the antigen-specificity of three CTL clones (CTL 3, 16, 45) was documented by A2/HER2369–377 tetramer staining (filled histogram). Non-binding A2/Melan-A26–35A27L multimer was used as negative control (open histogram). b The tumor recognition by CTL clones (second expansion) was documented by using the ovarian cancer cell line SKOV3tA2 (filled square) as target cell line. The HLA-A2+ HER2− K562tA2 cell line (filled triangle) and the HLA-A2− HER2+ SKOV3 cell line (filled circle) were used as negative controls. c Peptide avidity of CTL clones (third expansion) was determined by lysis of T2 cells pulsed with graded amounts of HER2369–377 peptide (filled circle) at a fixed E:T ratio of 60:1. T2 cells loaded with HIVpol476–484 peptide (open circle) were used as negative control. Half (50%) maximal target lysis occurred between 1 nM (10−9 M) and 10 nM (10−8 M) of peptide HER2369–377