Identification of antigenic peptides from novel renal cancer stem-like cell antigen, DNAJB8.

OBJECTIVES: To identify antigenic peptides of cancer stem-like cells (CSCs) antigen, DNAJB8, and establish a mouse CSCs-targeting immunotherapy model.

MATERIALS AND METHODS: To induce DNAJB8-specific immune reaction, we stimulated human CD8+ lymphocytes with antigen-presenting cells pulsed with a cocktail of three candidate HLA-A*24:02 restricted peptides and assessed peptide specific human cytotoxic T lymphocytes (CTLs) induction. One of the antigenic peptides showed identical amino acid sequence as corresponding mouse DNAJB8. We evaluated CTL induction with the peptide immunization in mouse model.

RESULTS: We confirmed peptide-specific interferon-γ secretions and cytotoxic activities of induced human CTLs. In vivo immunization with the peptide to mice, peptide-specific CTL response could be observed in mouse CD8+ T cells. Furthermore, immunization with the peptide showed significant anti-tumor effects compared with negative controls.

CONCLUSION: DNAJB8-derived peptide is a novel candidate for CSCs-targeting immunotherapy, and mouse models can be used to evaluate CSCs-targeting immunotherapy.