Figure 4: tCPs generate peptides with requirements for high-affinity MHC-I binding.
From: Thymoproteasomes produce unique peptide motifs for positive selection of CD8+ T cells
(a) Cell surface expression of H-2Db and H-2Kb on β5i-Flag MEFs (open square) and β5t-Flag MEFs (closed diamond) cultured with IFN-γ and brefeldin A was measured using flow cytometry. MEFs cultured without brefeldin A were used as the control of maximum (100%). Data are presented as the mean percentage±s.e.m. (n=3). Statistical analyses were performed by Student’s t-test. (b) Summary of H-2Db- and H-2Kb-binding peptides presented on β5i-Flag MEFs (blue circles; Set I) and β5t-Flag MEFs (red circles; Set T). The numbers of peptides with 8–14 lengths of residues and hydrophobic amino acids at their C termini are shown. (c) Frequencies of amino acids at C-terminal positions in peptides with 8–14 lengths of residues and hydrophobic amino acids at their C termini generated specifically by iCPs (blue bars; set I-T) and by tCPs (red bars; set T-I). (d) Frequencies of central anchors of peptides with 8–14 lengths of residues and hydrophobic amino acids at their C termini. Blue and red bars denoted as in c.
