HLA-A2-restricted point-mutated Survivin peptide elicited specific cytotoxic T lymphocyte reaction against hepatocarcinoma

Abstract

Objective To investigate the anti-hepatocarcinoma(anti-HCC) function of HLA-A2-restricted point-mutated Survivin peptide induced CTLs.Methods The HLA-A2-restricted Survivin nonapeptides were evaluated using bioinformatics software.The binding affinity of Survivin peptide to HLA-A2 molecular was determined with flow cytometry analysis.After peptide-induced CTLs were generated in vitro,flow cytometry and ELISA were performed to detect the levels of IFN-γ,which were secreted by reactive CTLs.Peptide-induced CTLs were co-cultured with hepatoma cell lines HepG2 and BEL-7402.The rates of tumor cells lysis were assayed using CytoTox 96(R) and the morphological changes of tumor cells were observed with inverted phase contrast microscope.Results Point-mutated Survivin nonapeptide Sur79M2 (KMSSGCAFL) was filtered out,which was shown higher scores compared with the wild-type peptide Sur79.Consistent with the results of software analysis,Sur79M2 showed higher binding ability in T2 binding assays.At the same time,Sur79M2-induced CTLs could release a large number of IFN-γ after incubated with target cells rather than Sur79.When co-cultured with HCC cell lines HepG2 and BEL-7402,Sur79M2-induced CTLs effectively lysis HepG2 on HLA-A2-restricted manner without killing effect on BEL-7402 that do not express HLA-A2 molecules.Conclusion Sur79M2 could elicited specific cytotoxic T lymphocytes in vitro,which were able to specifically kill HCC cell lines on HLA-A2-restricted manner. Key words: Survivin; Anti-hepatocarcinoma; Point-mutated peptide; HLA-A2-restricted