{"doi":"10.1136/jitc-2020-001875","title":"Shed antigen-induced blocking effect on CAR-T cells targeting Glypican-3 in Hepatocellular Carcinoma","abstract":"BACKGROUND: Glypican-3 (GPC3), a cell surface glycoprotein that is pathologically highly expressed in hepatocellular carcinoma (HCC), is an attractive target for immunotherapies, including chimeric antigen receptor (CAR) T cells. The serum GPC3 is frequently elevated in HCC patients due to the shedding effect of cell surface GPC3. The shed GPC3 (sGPC3) is reported to block the function of cell-surface GPC3 as a negative regulator. Therefore, it would be worth investigating the potential influence of antigen shedding in anti-GPC3 CAR-T therapy for HCC. METHODS: In this study, we constructed two types of CAR-T cells targeting distinct epitopes of GPC3 to examine how sGPC3 influences the activation and cytotoxicity of CAR-T cells in vitro and in vivo by introducing sGPC3 positive patient serum or recombinant sGPC3 proteins into HCC cells or by using sGPC3-overexpressing HCC cell lines. RESULTS: Both humanized YP7 CAR-T cells and 32A9 CAR-T cells showed GPC3-specific antitumor functions in vitro and in vivo. The existence of sGPC3 significantly inhibited the release of cytokines and the cytotoxicity of anti-GPC3 CAR-T cells in vitro. In animal models, mice carrying Hep3B xenograft tumors expressing sGPC3 exhibited a worse response to the treatment with CAR-T cells under both a low and high tumor burden. sGPC3 bound to CAR-T cells but failed to induce the effective activation of CAR-T cells. Therefore, sGPC3 acted as dominant negative regulators when competed with cell surface GPC3 to bind anti-GPC3 CAR-T cells, leading to an inhibitory effect on CAR-T cells in HCC. CONCLUSIONS: We provide a proof-of-concept study demonstrating that GPC3 shedding might cause worse response to CAR-T cell treatment by competing with cell surface GPC3 for CAR-T cell binding, which revealed a new mechanism of tumor immune escape in HCC, providing a novel biomarker for patient enrolment in future clinical trials and/or treatments with GPC3-targeted CAR-T cells.","journal":"Journal for ImmunoTherapy of Cancer","year":2021,"id":149078,"datarank":0.7130385286659547,"base_score":4.7535901911063645,"endowment":4.7535901911063645,"self_citation_contribution":0.7130385286659547,"citation_network_contribution":0.0,"self_endowment_contribution":0.7130385286659547,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":115,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9687,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":341739,"name":"Fang Gao","orcid":"0009-0004-4083-8649","position":1,"is_corresponding":false},{"id":634353,"name":"Zhanhui Gao","orcid":"0000-0001-9085-8438","position":2,"is_corresponding":false},{"id":635493,"name":"Lei Ao","orcid":null,"position":3,"is_corresponding":false},{"id":634354,"name":"Na Li","orcid":"0000-0003-0958-608X","position":4,"is_corresponding":false},{"id":635494,"name":"Sujuan Ma","orcid":null,"position":5,"is_corresponding":false},{"id":634355,"name":"Meng Jia","orcid":"0000-0001-7135-2204","position":6,"is_corresponding":false},{"id":255115,"name":"Nan Li","orcid":"0000-0002-1498-7139","position":7,"is_corresponding":false},{"id":634356,"name":"Peihua Lu","orcid":"0000-0002-6331-7369","position":8,"is_corresponding":false},{"id":277741,"name":"Beicheng Sun","orcid":"0000-0002-8657-7024","position":9,"is_corresponding":false},{"id":255131,"name":"Mitchell Ho","orcid":"0000-0002-9152-5405","position":10,"is_corresponding":false},{"id":635495,"name":"Shaochang Jia","orcid":null,"position":11,"is_corresponding":false},{"id":95215,"name":"Tong Ding","orcid":"0000-0002-0305-5037","position":12,"is_corresponding":false},{"id":634357,"name":"Wei Gao","orcid":"0000-0002-7889-1662","position":13,"is_corresponding":false},{"id":634352,"name":"Luan Sun","orcid":"0009-0004-7560-4826","position":0,"is_corresponding":true}],"reference_count":50,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-18T23:42:51.282401Z","pmid":"33833049","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}