Fig. 5.
CTL recognition and cross-reactivity of wt p5372P and p5372R on SCCHN cells. Wt p5372P and p5372R-specific CTL recognition of R/P donor (5A) and R/R donor (5B) of naturally processed peptide expressed by SCCHN cell lines SCC-4 (P/P), PCI-13 (R/R) and SCC-90 (R/P) using IFN-γ ELISPOT assays. Recognition was confirmed using stable transfectants of p53 null Saos-2 cells, which express only one p53 allele (72R or 72P, 5C) in the P/P donor. IFN-γ release was blocked by an anti-HLA class I mAb, but not an HLA class II-specific mAb (not shown). No reactivity was observed using HLA-A2− SCCHN cells (not shown). SCCHN cells were treated with IFN-γ (100 IU/ml for 72 h at 37°C)