FIGURE 3 from HDAC6 Inhibition Releases HR23B to Activate Proteasomes, Expand the Tumor Immunopeptidome and Amplify T-cell Antimyeloma Activity

Effect of HDAC6 inhibitors on the murine MHC class I immunopeptidome. A, Number of peptides eluted from murine MHC class I molecule at each indicated peptide lengths (range = 6 to 15 amino acids). B, Effect of HDAC6 inhibitor treatment on SIINFEKL presentation. C, Number of peptides and their fold increase after treatment of E.G7-Ova cells with each HDAC6 inhibitor. D, The terminal amino acids of the top 50 peptides upregulated by tubastatin-A or ACY-738 treatment were analyzed. Shown is the relative percent for each terminal amino acid for the top 50 peptides upregulated by treatment with each HDAC6 inhibitor. E, Shown are gene accession numbers for the top 20 peptides most upregulated following treatment with either tubastatin-A or ACY-738. Red asterisks indicate genes and peptides that were upregulated following treatment with both of the HDAC6 inhibitors.