{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,7]],"date-time":"2026-11-07T00:30:40Z","timestamp":1794011440021,"version":"4.8.0"},"reference-count":45,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T00:00:00Z","timestamp":1767312000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers, with a 5-year survival rate below 10%, largely due to late-stage diagnosis and the limited effectiveness of conventional therapies such as surgery, chemotherapy, and radiation. Claudin 18.2 (CLDN18.2)has emerged as a promising target for PDAC. While single-chain variable fragment (scFv)-based CAR-T cells targeting CLDN18.2 have demonstrated therapeutic potential, CAR-T cells engineered with variable heavy-chain-only domains (VHH) exhibit superior efficacy, highlighting the advantages of VHH-based constructs in targeting this antigen. However, the therapeutic efficacy of anti-CLDN18.2 VHH-CAR-T cells remains to be fully elucidated, as previous studies have not comprehensively characterized\n                      <jats:italic>in vivo<\/jats:italic>\n                      performance or mechanistic advantages over scFv-based counterparts.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      To characterize the therapeutic potential of anti-CLDN18.2 VHHs, we employed phage display technology to screen a VHH library, resulting in the identification of three positive clones. These candidates were further evaluated and ranked based on binding affinity and multi-round cytotoxicity in Chimeric antigen receptor T (CAR-T) cell models. To reduce immunogenicity, the lead VHH was humanized. VHH-CAR-T cells incorporating this humanized domain were assessed through\n                      <jats:italic>in vitro<\/jats:italic>\n                      assays measuring cytokine secretion and target cell lysis, followed by\n                      <jats:italic>in vivo<\/jats:italic>\n                      studies to evaluate antitumor efficacy in relevant xenograft models.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      High-affinity anti-CLDN18.2 VHHs from phage libraries and engineered CAR-T cells using HM2, a humanized VHH, as the antigen-binding domain were successfully identified. Notably, HM2-CAR-T cells demonstrated potent and sustained cytokine secretion and cytotoxic activity against CLDN18.2-expressing tumor cells\n                      <jats:italic>in vitro<\/jats:italic>\n                      . More importantly, these VHH-based CAR-T cells achieved significant antitumor efficacy\n                      <jats:italic>in vivo<\/jats:italic>\n                      , underscoring the translational potential of VHH-CAR constructs as a next-generation therapeutic platform with enhanced performance and reduced immunogenicity compared to conventional scFv-based designs.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>This study establishes an effective framework for developing CLDN18.2-specific VHHs and demonstrates their successful integration into CAR-T cell therapy. The humanized HM2-CAR-T cells not only maintain high antigen specificity but also exhibit strong effector functions and pronounced antitumor activity in preclinical models. These findings support the clinical promise of VHH-based CAR-T cells as a next-generation immunotherapy for CLDN18.2-expressing malignancies, particularly PDAC, where effective treatment options remain limited.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fimmu.2025.1638585","type":"journal-article","created":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T06:29:07Z","timestamp":1767335347000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":4,"title":["VHH-based CAR-T cells targeting Claudin 18.2 show high efficacy in pancreatic cancer models"],"prefix":"10.3389","volume":"16","author":[{"given":"Ying","family":"Xing","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gangqiang","family":"Shi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhengli","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiancheng","family":"Liu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linghu","family":"Nie","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yiqin","family":"Song","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shilin","family":"Sun","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mike\u00a0K.\u00a0S.","family":"Chan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michelle B. 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