Identification of an HLA‐A*24:02‐restricted α‐fetoprotein signal peptide‐derived antigen and its specific T‐cell receptor for T‐cell immunotherapy.

Summary: Hepatocellular carcinoma (HCC) is the most common type of liver cancer with limited treatments. Asia has the highest HCC incidence rates; China accounts for over 50% of all HCC cases worldwide. T‐cell receptor (TCR) ‐engineered T‐cell immunotherapies specific for human leukocyte antigen (HLA) ‐A*02:01‐restricted α‐fetoprotein (AFP) peptide have shown encouraging results in clinics. HLA‐A*24:02 is more common than HLA‐A*02:01 in Asian countries, including China. Here we identified a novel HLA‐A*24:02‐restricted peptide KWVESIFLIF (AFP2–11) located in AFP signal peptide domain by mass spectrometric analysis of HLA‐bound peptides from HepG2 cells. A TCR (KWV3.1) specific for AFP2–11‐HLA‐A*24:02 was isolated from peripheral blood mononuclear cells of a healthy donor. The binding affinity of soluble KWV3.1 to its antigen was determined to be ~55 μm, within the affinity range of native TCRs for self‐antigens. KWV3.1‐transfected T cells could specifically activate and kill AFP2–11 pulsed T2‐A24 cells and AFP+ HLA‐A*24:02+ tumor cell lines, demonstrating that AFP2–11 can be naturally presented on the surface of AFP+ tumor cell lines. The newly identified antigenic peptide can provide a novel target for immunotherapeutic strategies for patients with AFP+ HLA‐A*24:02+ HCC. [ABSTRACT FROM AUTHOR]