Identification of an H2-Kb or H2-Db restricted and glypican-3-derived cytotoxic T-lymphocyte epitope peptide

Abstract

Glypican-3 (GPC3) is overexpressed in human hepatocellular carcinoma (HCC) but not expressed in normal tissues except for placenta and fetal liver and therefore is an ideal target for cancer immunotherapy. In this study, we identified an H2-Kb or H2-Db restricted and murine GPC3 (mGPC3)-derived cytotoxic T-lymphocyte (CTL) epitope peptide in C57BL/6 (B6) mice, which can be used in the design of preclinical studies of various therapies with GPC3-target immunotherapy in vivo. First, 11 types of 9- to 10-mer peptides predicted to bind with H2-Kb or H2-Db were selected from the mGPC3 amino acid sequence based on the binding score as calculated by the BIMAS software. We evaluated the peptide-binding affinity and confirmed that all peptides were able to bind to H2-Kb or H2-Db by in vitro cellular binding assay. Subsequently, a mixed peptide vaccine and single peptide vaccine were given to B6 mice to evaluate immunogenic potential of the 11 selected peptides. Using the splenocytes from peptide-vaccinated mice, interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) assays showed that mGPC3-1127–136 (AMFKNNYPSL) peptide was the most efficient for inducing CTLs among the 11 peptides. Next, we demonstrated that the mGPC3-1 peptide-specific CTL line could recognize mGPC3-expressing cancer cells, suggesting that mGPC3-1 peptide was an endogenously presented peptide. In conclusion, we identified mGPC3-1 as an H2-Kb or H2-Db restricted, mGPC3-derived CTL epitope peptide.

Glypican‐3: A promising biomarker for hepatocellular carcinoma diagnosis and treatment

“…In addition to the two aforementioned peptide vaccines, other GPC3‐derived CTL epitopes have been identified, including murine GPC3‐1 127–136 peptide . Moreover, five GPC3‐derived long peptides that can induce HLA class II‐restricted Th1‐cell response have been identified, and the Th1‐cell response induced by these peptides was found to be strongly correlated with prolonged overall survival .…”

“…In addition to the two aforementioned peptide vaccines, other GPC3-derived CTL epitopes have been identified, including murine GPC3-1 [127][128][129][130][131][132][133][134][135][136] peptide. 144 Moreover, five GPC3-derived long peptides that can induce HLA class II-restricted Th1-cell response have been identified, and the Th1-cell response induced by these peptides was found to be strongly correlated with prolonged overall survival. 145 Furthermore, one of the five peptides, GPC3 , could be effectively cross-presented when encapsulated in liposomes, and it elicited both Th1-cell response and CTL response.…”

Prediction and preliminary screening of HLA‐A*0201‐restricted epitope peptides of human GPC3

“…As a promising target of HCC immunotherapy, GPC3 peptide vaccines are attractive, and MHC‐I‐restricted immune‐dominant epitopes of human GPC3 need to be identified. Recent studies have provided encouraging results that GPC3‐derived peptide vaccine could induce specific CTLs in mice (Motomura et al ., ; Iwama et al ., ); however, no report have been shown in human.…”

Tumor Microenvironment: Extracellular Matrix Alterations Influence Tumor Progression

“…Glypican-3 represents a promising immunotherapeutic target. Different GPC3-targeting therapies have been developed: the use of humanized anti-GPC3 cytotoxic antibodies, the treatment with peptide/DNA vaccines, immunotoxin therapies, and genetic therapies (107,(157)(158)(159)(160)(161)(162).…”