{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T11:10:33Z","timestamp":1788174633508,"version":"build-2803163510"},"reference-count":39,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T00:00:00Z","timestamp":1777939200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004846","name":"Beijing University of Chinese Medicine","doi-asserted-by":"publisher","award":["9011451310032"],"award-info":[{"award-number":["9011451310032"]}],"id":[{"id":"10.13039\/501100004846","id-type":"DOI","asserted-by":"publisher"}]},{"award":["9011451310032"],"award-info":[{"award-number":["9011451310032"]}],"id":[{"id":"https:\/\/ror.org\/05damtm70","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>In recent years, the feasibility of immunotherapy targeting activated fibroblasts in pulmonary fibrosis has received further support. Recent studies have shown that transient FAP-targeted immunotherapy can alleviate pulmonary fibrosis by eliminating excessively activated fibroblasts, improving the aberrant extracellular matrix environment, and promoting alveolar cell lineage remodeling, suggesting that FAP-associated pathological stromal cells are amenable to therapeutic intervention. Based on this, research on FAP-centered engineered cell therapies is being gradually extended from settings such as myocardial fibrosis to pulmonary fibrosis. In this context, primary human NK cells represent a promising effector cell platform, as they are generally associated with a lower risk of severe treatment-related toxicities and relatively limited in vivo persistence, which may confer a more controllable therapeutic window. This feature is particularly important in fibrotic diseases, because long-term and continuous depletion of fibroblast populations may disrupt tissue homeostasis and injury repair. In addition, current studies of FAP-targeted CAR-NK therapy have mainly relied on NK cell lines such as NK-92, but these systems may not fully reflect the functional characteristics, receptor signaling, or clinical potential of primary human NK cells. Based on these considerations, it is necessary to develop a FAP-targeted cell therapy platform with greater clinical relevance for pulmonary fibrosis. In this study, we established a primary human FAP-CAR-NK-cell platform and conducted a proof-of-concept evaluation in pulmonary fibrosis-related models, including in vitro systems, a human pulmonary fibrosis-like organoid model, and an acute in vivo observation model. The main novelty of this study lies in the use of primary human NK cells for FAP-targeted intervention in pulmonary fibrosis-related models. We focused on whether these engineered cells could selectively target and eliminate FAP-positive activated fibroblasts, retain effector function in a fibrotic microenvironment, and show short-term feasibility after adoptive transfer. The study was not intended to assess long-term therapeutic efficacy or systemic safety, but rather to examine the feasibility of FAP-directed fibroblast targeting by primary human CAR-NK cells in pulmonary fibrosis and to provide a basis for further preclinical investigation.<\/jats:p>","DOI":"10.3390\/ijms27094128","type":"journal-article","created":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T13:23:37Z","timestamp":1777987417000},"page":"4128","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Proof-of-Concept Evaluation of Primary Human FAP-CAR-NK Cells Targeting Activated Fibroblasts in Pulmonary Fibrosis"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-0917-0257","authenticated-orcid":false,"given":"Geping","family":"Wu","sequence":"first","affiliation":[{"name":"School of Life Sciences, Beijing University of Chinese Medicine, Beijing 100013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6345-4841","authenticated-orcid":false,"given":"Zhiming","family":"Ling","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Beijing University of Chinese Medicine, Beijing 100013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-1459-0337","authenticated-orcid":false,"given":"Wei","family":"Lin","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Beijing University of Chinese Medicine, Beijing 100013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Beijing University of Chinese Medicine, Beijing 100013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiuying","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Beijing University of Chinese Medicine, Beijing 100013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianxun","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Beijing University of Chinese Medicine, Beijing 100013, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1445","DOI":"10.1007\/s00228-024-03720-7","article-title":"Real-world safety and effectiveness of pirfenidone and nintedanib in the treatment of idiopathic pulmonary fibrosis: A systematic review and meta-analysis","volume":"80","author":"Kou","year":"2024","journal-title":"Eur. J. Clin. Pharmacol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"101945","DOI":"10.1016\/j.berh.2024.101945","article-title":"Potential therapeutic targets of fibrosis in inflammatory rheumatic diseases","volume":"38","author":"Su","year":"2024","journal-title":"Best Pract. Res. Clin. Rheumatol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1038\/s41586-020-2938-9","article-title":"Fibrosis: From mechanisms to medicines","volume":"587","author":"Henderson","year":"2020","journal-title":"Nature"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"eabp8964","DOI":"10.1126\/science.abp8964","article-title":"The extracellular matrix and the immune system: A mutually dependent relationship","volume":"379","author":"Sutherland","year":"2023","journal-title":"Science"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"113993","DOI":"10.1016\/j.isci.2025.113993","article-title":"Mechanobiology and the extracellular matrix in pulmonary fibrosis","volume":"28","author":"Ganzleben","year":"2025","journal-title":"iScience"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"783","DOI":"10.1007\/s10555-020-09909-3","article-title":"The role of fibroblast activation protein in health and malignancy","volume":"39","author":"Fitzgerald","year":"2020","journal-title":"Cancer Metastasis Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1164\/rccm.202110-2414OC","article-title":"Comprehensive Analysis of Fibroblast Activation Protein Expression in Interstitial Lung Diseases","volume":"207","author":"Yang","year":"2023","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e185","DOI":"10.1016\/S2665-9913(20)30421-5","article-title":"(68)Ga-FAPI-04 PET-CT for molecular assessment of fibroblast activation and risk evaluation in systemic sclerosis-associated interstitial lung disease: A single-centre, pilot study","volume":"3","author":"Bergmann","year":"2021","journal-title":"Lancet Rheumatol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1725","DOI":"10.1038\/s41588-024-01819-2","article-title":"Mapping spatially resolved transcriptomes in human and mouse pulmonary fibrosis","volume":"56","author":"Franzen","year":"2024","journal-title":"Nat. Genet."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1038\/s41588-025-02080-x","article-title":"Spatial transcriptomics identifies molecular niche dysregulation associated with distal lung remodeling in pulmonary fibrosis","volume":"57","author":"Vannan","year":"2025","journal-title":"Nat. Genet."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3748","DOI":"10.1038\/s41467-025-59093-7","article-title":"Targeted immunotherapy rescues pulmonary fibrosis by reducing activated fibroblasts and regulating alveolar cell profile","volume":"16","author":"Yan","year":"2025","journal-title":"Nat. Commun."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"114760","DOI":"10.1016\/j.intimp.2025.114760","article-title":"Fibroblast activation protein-targeted chimeric antigen-receptor-modified NK cells alleviate cardiac fibrosis","volume":"157","author":"Zheng","year":"2025","journal-title":"Int. Immunopharmacol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"10713","DOI":"10.1038\/s41598-017-11126-y","article-title":"A TCR-based Chimeric Antigen Receptor","volume":"7","author":"Walseng","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1056\/NEJMoa1910607","article-title":"Use of CAR-Transduced Natural Killer Cells in CD19-Positive Lymphoid Tumors","volume":"382","author":"Liu","year":"2020","journal-title":"N. Engl. J. Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"114145","DOI":"10.1016\/j.celrep.2024.114145","article-title":"Precision off-the-shelf natural killer cell therapies for oncology with logic-gated gene circuits","volume":"43","author":"Frankel","year":"2024","journal-title":"Cell Rep."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Golubovskaya, V., Sienkiewicz, J., Sun, J., Zhang, S., Huang, Y., Zhou, H., Harto, H., Xu, S., Berahovich, R., and Wu, L. (2023). CAR-NK Cells Generated with mRNA-LNPs Kill Tumor Target Cells In Vitro and In Vivo. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms241713364"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1137","DOI":"10.1084\/jem.20122344","article-title":"Depletion of stromal cells expressing fibroblast activation protein-alpha from skeletal muscle and bone marrow results in cachexia and anemia","volume":"210","author":"Roberts","year":"2013","journal-title":"J. Exp. Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1161","DOI":"10.1016\/j.stem.2022.07.006","article-title":"Wound healing, fibroblast heterogeneity, and fibrosis","volume":"29","author":"Talbott","year":"2022","journal-title":"Cell Stem Cell"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Niu, W., Wang, B., Zhang, Y., Wang, C., Cao, J., Li, J., He, Y., and Lei, P. (2024). Efficacy and safety evaluation of cross-reactive Fibroblast activation protein scFv-based CAR-T cells. Front. Immunol., 15.","DOI":"10.3389\/fimmu.2024.1433679"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2283","DOI":"10.1038\/s41596-023-00827-6","article-title":"A distal lung organoid model to study interstitial lung disease, viral infection and human lung development","volume":"18","author":"Schneider","year":"2023","journal-title":"Nat. Protoc."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e202201853","DOI":"10.26508\/lsa.202201853","article-title":"Modeling fibrotic alveolar transitional cells with pluripotent stem cell-derived alveolar organoids","volume":"6","author":"Ptasinski","year":"2023","journal-title":"Life Sci. Alliance"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1038\/s41586-024-07791-5","article-title":"Human organoids with an autologous tissue-resident immune compartment","volume":"633","author":"Recaldin","year":"2024","journal-title":"Nature"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"116214","DOI":"10.1016\/j.celrep.2025.116214","article-title":"Organoids as models of immune-organ interaction","volume":"44","author":"Harter","year":"2025","journal-title":"Cell Rep."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"816","DOI":"10.1096\/fj.03-1273rev","article-title":"TGF-beta signaling and the fibrotic response","volume":"18","author":"Leask","year":"2004","journal-title":"FASEB J."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Piersma, B., Bank, R.A., and Boersema, M. (2015). Signaling in Fibrosis: TGF-beta, WNT, and YAP\/TAZ Converge. Front. Med., 2.","DOI":"10.3389\/fmed.2015.00059"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1165\/rcmb.2020-0504OC","article-title":"Connective-Tissue Growth Factor Contributes to TGF-beta1-induced Lung Fibrosis","volume":"66","author":"Yanagihara","year":"2022","journal-title":"Am. J. Respir. Cell Mol. Biol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"797","DOI":"10.1096\/fj.00-0233com","article-title":"Molecular mechanisms of TGF-(beta) antagonism by interferon (gamma) and cyclosporine A in lung fibroblasts","volume":"15","author":"Eickelberg","year":"2001","journal-title":"FASEB J."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3559","DOI":"10.1038\/s41467-020-17358-3","article-title":"Alveolar regeneration through a Krt8+ transitional stem cell state that persists in human lung fibrosis","volume":"11","author":"Strunz","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"934","DOI":"10.1038\/s41556-020-0542-8","article-title":"Persistence of a regeneration-associated, transitional alveolar epithelial cell state in pulmonary fibrosis","volume":"22","author":"Kobayashi","year":"2020","journal-title":"Nat. Cell Biol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"e165612","DOI":"10.1172\/JCI165612","article-title":"Regulation of epithelial transitional states in murine and human pulmonary fibrosis","volume":"133","author":"Wang","year":"2023","journal-title":"J. Clin. Investig."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"8710","DOI":"10.1038\/s41467-025-63735-1","article-title":"Aberrant intermediate alveolar epithelial cells promote pathogenic activation of lung fibroblasts in preclinical fibrosis models","volume":"16","author":"Hoffman","year":"2025","journal-title":"Nat. Commun."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"575","DOI":"10.1038\/s41586-021-03549-5","article-title":"Cross-tissue organization of the fibroblast lineage","volume":"593","author":"Buechler","year":"2021","journal-title":"Nature"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Gauthier, V., Kyriazi, M., Nefla, M., Pucino, V., Raza, K., Buckley, C.D., and Alsaleh, G. (2023). Fibroblast heterogeneity: Keystone of tissue homeostasis and pathology in inflammation and ageing. Front. Immunol., 14.","DOI":"10.3389\/fimmu.2023.1137659"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"103504","DOI":"10.1016\/j.xpro.2024.103504","article-title":"Protocol for X-ray irradiation of C57BL\/6J recipient mice followed by the transplantation of mTomato-expressing bone marrow cells","volume":"6","author":"Vo","year":"2025","journal-title":"STAR Protoc."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1165\/rcmb.2017-0096ST","article-title":"An Official American Thoracic Society Workshop Report: Use of Animal Models for the Preclinical Assessment of Potential Therapies for Pulmonary Fibrosis","volume":"56","author":"Jenkins","year":"2017","journal-title":"Am. J. Respir. Cell Mol. Biol."},{"key":"ref_36","first-page":"100781","article-title":"Humanized Mouse Models for Immuno-Oncology Research: A Review and Implications in Lung Cancer Research","volume":"6","author":"Park","year":"2025","journal-title":"JTO Clin. Res. Rep."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1186\/s13014-025-02617-8","article-title":"Radiation-induced lung injury: From mechanism to prognosis and drug therapy","volume":"20","author":"Wang","year":"2025","journal-title":"Radiat. Oncol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3603","DOI":"10.7150\/thno.93519","article-title":"Highlighting fibroblast plasticity in lung fibrosis: The WI-38 cell line as a model for investigating the myofibroblast and lipofibroblast switch","volume":"14","author":"Marega","year":"2024","journal-title":"Theranostics"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"e157338","DOI":"10.1172\/JCI157338","article-title":"The ZIP8\/SIRT1 axis regulates alveolar progenitor cell renewal in aging and idiopathic pulmonary fibrosis","volume":"132","author":"Liang","year":"2022","journal-title":"J. Clin. Investig."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/9\/4128\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T13:25:33Z","timestamp":1777987533000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/9\/4128"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,5]]},"references-count":39,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["ijms27094128"],"URL":"https:\/\/doi.org\/10.3390\/ijms27094128","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,5]]}}}