HLA-A2-restricted glypican-3 peptide-specific CTL clones induced by peptide vaccine show high avidity and antigen-specific killing activity against tumor cells.

Glypican-3 (GPC3) is an onco-fetal antigen that is overexpressed in human hepatocellular carcinoma (HCC), and is only expressed in the placenta and embryonic liver among normal tissues. Previously, we identified an HLA-A2-restricted GPC3(144-152) (FVGEFFTDV) peptide that can induce GPC3-reactive CTLs without inducing autoimmunity in HLA-A2 transgenic mice. In this study, we carried out a phase I clinical trial of HLA-A2-restricted GPC3(144-152) peptide vaccine in 14 patients with advanced HCC. Immunological responses were analyzed by ex vivo γ-interferon enzyme-linked immunospot assay. The frequency of GPC3(144-152) peptide-specific CTLs after vaccination (mean, 96; range, 5-441) was significantly larger than that before vaccination (mean, 6.5; range, 0-43) (P < 0.01). An increase in the GPC3(144-152) peptide-specific CTL frequency was observed in 12 (86%) of 14 patients after vaccination. Additionally, there was a significant correlation between the maximum value of GPC3(144-152) peptide-specific CTLs after vaccination and the dose of the peptide injected (P = 0.0166, r = 0.665). Moreover, we established several GPC3(144-152) peptide-specific CTL clones from PBMCs of patients vaccinated with GPC3(144-152) peptide by single cell sorting using Dextramer and CD107a antibody. These CTL clones had high avidity (the recognition efficiency showing 50% cytotoxicity was 10(-10) or 10(-11) M) and could recognize HCC cell lines expressing GPC3 in an HLA-class I-restricted manner. These results suggest that GPC3(144-152) peptide vaccine can induce high avidity CTLs capable of killing HCC cells expressing GPC3. This trial was registered with University Hospital Medical Information Network number 000001395.

Yoshikawa T ，Nakatsugawa M ，Suzuki S ，Shirakawa H ，Nobuoka D ，Sakemura N ，Motomura Y ，Tanaka Y ，Hayashi S ，Nakatsura T ... -  《-》

Analysis of cytotoxic T lymphocytes from a patient with hepatocellular carcinoma who showed a clinical response to vaccination with a glypican‑3‑derived peptide.

Tada Y ，Yoshikawa T ，Shimomura M ，Sawada Y ，Sakai M ，Shirakawa H ，Nobuoka D ，Nakatsura T ... -  《-》

Identification of HLA-A2- or HLA-A24-restricted CTL epitopes possibly useful for glypican-3-specific immunotherapy of hepatocellular carcinoma.

Komori H ，Nakatsura T ，Senju S ，Yoshitake Y ，Motomura Y ，Ikuta Y ，Fukuma D ，Yokomine K ，Harao M ，Beppu T ，Matsui M ，Torigoe T ，Sato N ，Baba H ，Nishimura Y ... -  《CLINICAL CANCER RESEARCH》

[Cancer peptide vaccine targeted glypican-3 antigen].

Nakatsura T 《-》

[Usefulness of a novel oncofetal antigen, glypican-3, for diagnosis and immunotherapy of hepatocellular carcinoma].

Nishimura Y ，Nakatsura T ，Senju S 《-》