Identification of HLA-A2-restricted CTL epitopes encoded by Ki-67 antigen

Objective To identify the HLA-A2-restricted CTL epitopes encoded by antigen segment of Ki-67 for preparation of tumor vaccines. Methods Two epitope prediction databases ( BIMAS and SYFPEITHI) were used to predict the epitopes of Ki-67, and 7 peptides were synthesized as the candi-dates. The prediction was evaluated by peptide-binding test. ELISPOT was used to inspect the IFN-γ secre-ted by CTLs in order to reflect the immunogenicity of the peptides. Results The purities of synthetic pep-tides and positive control peptide were all above 95%. Peptide-binding test displayed that LQGETQLLV (280-288) of Ki-67 could bind with HLA-A2 molecule more strongly. ELISPOT assay displayed that LQGETQLLV could induce activation of specific CTLs. Conclusion LQGETQLLV (280-288) might be the HLA-A2-restricted CTL epitope of Ki-67 antigen. Key words: Ki-67 antigen; CTL; Epitope