High vaccination efficiency of low-affinity epitopes in antitumor immunotherapy
J. Clin. Invest. David-Alexandre Gross, et al. 113:425 doi:10.1172/JCI19418 [Go to this article.]

Figure 2
Quality of the mTERT epitope–specific CTL repertoire. From 5 to 10 mice were vaccinated with the high-affinity p545 and p797, the heteroclitical p572Y and p988Y, or the nonself controls p876 and fluM58 peptides. Results represent the mean per group and are expressed as mean ± SEM. (a) CTL frequency was evaluated ex vivo 11 days after vaccination by a standard 24-hour IFN-γ ELISPOT assay with cognate native peptides. Spot-forming units (SFUs) for 10⁶ CD8⁺ splenocytes are represented. (b) Avidity of CTLs after 1 week of in vitro restimulation was defined by measuring the normalized concentration of native peptide that gives 50% of maximal lysis (KC₅₀). The normalized concentration was the ratio of peptide concentration to the RA. CTL frequency and KC₅₀ were compared using the nonparametric Mann-Whitney U test; asterisks in a and b indicate values that were considered significant (P < 0.05). (c) Peripheral blood mononuclear cells from naive or immunized mice 11 days earlier were stained with specific PE-coupled HLA-A*0201/p797 or (d) HLA-A*0201/p572Y tetramer together with anti-CD8–APC, anti-TCRβ–CyChrome, and anti-CD44–FITC. Representatives staining gated in TCRβ⁺ CD44⁺ are shown.