FIGURE 5.

GPI-linked K^d-peptide P1 complexes are less efficiently recognized. A, RMA-S-K^d cells (squares), RMA-S-K^d_GPI (circles), or untransfected RMA-S cells (triangles) were incubated with the indicated concentrations of PbCS(biotin) peptide at 37 °C for 1 h, and the peptide binding was assessed by flow cytometry as mean fluorescent intensity (MFI). B, alternatively, RMA-S-K^d cells (open symbols) were incubated at 32 °C with graded concentrations of PbCS(biotin) peptide for 30 min (open squares), 60 min (open circles), or 90 min (open diamonds). For RMA-S-K^d_GPI cells (closed symbols), the incubations were performed at 37 °C for 1 min (filled triangles), 5 min (filled diamonds), and 10 min (filled squares). One out of four experiments is shown. B, RMA-S-K^d cells (squares) were incubated at 32 °C for 90 min and RMA-S-K^d_GPI cells (triangles) at 37 °C for 5 min with graded concentrations of PbCS(ABA) peptide and their recognition by cloned S14 CTL assessed in a ⁵¹Cr release assay. One out of three experiments is shown.