Prediction synthesis and identification of HLA-A2-restricted cytotoxic T lymphocyte epitopes of the tumor antigen MAGE-n

OBJECTIVE: To predict, synthesize, and identify HLA-A2-restricted cytotoxic T lymphocyte (CTL) epitopes of the tumor the novel antigen MAGE-n. METHODS: Long-distance prediction system SYFPEITHI combined with polynomial method was used to predict the HLA-A2-restricted CTL epitopes of the tumor antigen MAGE-n. The candidate epitopes were synthesized with solid phase strategies, purified with reverse phase high-performance liquid chromatography and identified by mass spectrometry, The binding affinity and biding stability of the synthesized peptides were examined by cellular competition-based HLA-A2 peptide binding assay, T2 peptide stabilization assay, and peptide-major histocompatibility complex dissociation assay. RESULTS: Five HLA-A2-restricted CTL epitopes of MAGE-n were selected: The epitopes QLVFGIEVV (159-167), IMPKTGGLI (195-203), and FLIIVLMI (201-209) with high HLA-A2 binding affinity (LC(50) < 15 micro mol/L) and binding stability (DT(50) > 6 h) were selected as candidate epitopes for further study in immunotherapy for tumor. CONCLUSION: Epitope prediction combined with epitope reconstruction improves the study of HLA-A2-restricted CTL epitopes of the tumor antigen MAGE-n. The selected epitopes of MAGE-n may be used in the design of therapeutic peptide vaccine for hepatocellular carcinoma.