Figure 3.

Cytotoxic activities of CTL207‐11 oligo‐clonal CTL induced with IGSF11‐9‐207 peptide. Cytotoxic activities of CTL207‐11 cells were examined using a 4‐h ⁵¹Cr‐release assay. (a) Cytotoxic activities to T2 cells (HLA‐A*0201) pulsed with IGSF11‐9‐207 (▪) or control (□) peptides. (b) Cytotoxic activities to SNU475 (both IGSF11 and HLA‐A*0201 positive), SNU‐C4 (HLA‐A*0201 positive and IGSF11 negative) and MKN74 (IGSF11 positive and HLA‐A*0201 negative). CTL207‐11 showed potent cytotoxic activities against not only T2 cells pulsed with IGSF11‐9‐207 but also SNU475 cells. There was no significant cytotoxic activity against SNU‐C4 or MKN74, both of which do not express HLA‐A*0201 and IGSF11 simultaneously. (c) A cold target inhibition assay. ⁵¹Cr‐labeled SNU475 cells were used as hot targets at an E/T ratio of 20. T2 cells pulsed with IGSF11‐9‐207 (▪) or control (□) peptides were used as a cold target. We added T2 cells to SNU475 cells in each microculture at various cold target/hot target ratios, and examined cytotoxic activity. T2 cells inhibited cytotoxic activity against SNU475 cells only when pulsed with IGSF11‐9‐207 peptides. (d) An antibody‐blocking assay. Cytotoxic activity against SNU475 cells was inhibited by anti‐CD8 or anti‐HLA‐class I monoclonal antibody. *E/T ratio: 20.