FIGURE 3.

Good correlation between UV-mediated peptide exchange and HPLC binding assays. Correlations between the s/p ratio obtained with the UV-mediated peptide exchange binding assay and the IC₅₀ obtained with the HPLC binding assay are plotted for HLA-E*01:03, HLA-E*01:01, Mamu-E, and Qa-1^b as indicated. IC₅₀ values for peptides represented as black circles correspond to HIV- and SIV-derived peptides previously described to bind Mamu-E (15, 42, 43) and peptides previously described to bind Qa-1^b (13). IC₅₀ values for peptides represented as gray triangles correspond to those previously published in the context of only HLA-E*01:03 (7). Dotted lines represent the thresholds indicating binders and strong binders to each MHC-E molecule, according to the UV-mediated peptide exchange binding assay. The s/p ratios represent mean values from at least two independent experiments with two biological replicates and two technical replicates. IC₅₀ values represent one experiment. Statistical significance was tested by nonparametric Spearman correlation analysis.