An HLA-A3-binding prostate acid phosphatase-derived peptide can induce CTLs restricted to HLA-A2 and -A24 alleles

Area of Science:

• Immunology
• Oncology
• Vaccinology

Background:

• Previous research identified peptide vaccine candidates for HLA-A3 supertype-positive cancer patients.
• The current study investigates the efficacy of these peptides in inducing cytotoxic T lymphocyte (CTL) activity restricted to HLA-A2, HLA-A24, and HLA-A26 alleles.

Purpose of the Study:

• To screen peptide vaccine candidates for binding affinity to specific HLA alleles (HLA-A*0201, -A*0206, -A*0207, -A*2402, -A*2601).
• To evaluate the ability of these peptides to induce CTL activity in peripheral blood mononuclear cells (PBMCs) from prostate cancer patients.
• To determine the potential of a specific peptide for broader application in cancer immunotherapy.

Main Methods:

• Screening of fourteen peptides for binding activity to five HLA-A alleles.
• Testing peptide-induced CTL activity in PBMCs from prostate cancer patients.
• Characterization of CTL activity, including T cell subset (CD8+) and specificity.

Main Results:

• One prostate acid phosphatase-derived peptide demonstrated binding to HLA-A*0201, -A*0206, and -A*2402 molecules.
• This peptide successfully induced HLA-A2 and HLA-A24 restricted CTL activity in patient PBMCs.
• The observed cytotoxicity was mediated by peptide-specific, CD8+ T cells.

Conclusions:

• A peptide vaccine candidate targeting prostate acid phosphatase shows broad applicability.
• This peptide can induce CTL activity in cancer patients positive for HLA-A3 supertype, HLA-A2, and HLA-A24 alleles.
• The findings support the development of this peptide for a wider range of cancer patients.