{"title":"MARCO expression on myeloid-derived suppressor cells is essential for their differentiation and immunosuppression.","authors":"Sijia Liu, Binle Tian, Na Wang, Zhilong Wang, Wen Zhang, Qi Li, JianFei Wang, Guo-Huang Fan, Caicun Zhou","doi":"10.1038/s41420-025-02627-1","DOIUrl":null,"url":null,"abstract":"<p><p>Myeloid-derived suppressor cells (MDSCs) significantly contribute to the immunosuppressive tumor microenvironment (TME), and targeted inhibition of MDSCs is a potential therapeutic strategy against cancer. Here, we identify macrophage receptor with collagenous structure (MARCO) as a critical regulator of MDSC differentiation and immunosuppression in breast cancer. The present study demonstrates that MARCO is expressed on MDSCs, and breast tumor-derived exosomes (TDEs) enriched with macrophage migration inhibitory factor (MIF) promote MDSC differentiation and amplify immunosuppressive activity by up-regulating MARCO. Genetic ablation of MARCO in a murine breast cancer model attenuated tumor growth, accompanied by reduced monocytic MDSCs (M-MDSCs) and total tumor-associated macrophages (TAMs), along with enhanced infiltration of CD8<sup>+</sup> T cells and natural killer (NK) cells. Furthermore, we developed a specific MARCO down-regulation-promoting monoclonal antibody that impeded TDE-induced MDSC differentiation and immunosuppression. In vivo, MARCO down-regulating antibody suppressed tumor growth and reprogrammed the TME by diminishing immunosuppressive MDSCs and TAMs and revitalizing CD8<sup>+</sup> T cells and NK cells. Strikingly, combining the MARCO down-regulating antibody with PD-1 blockade synergistically enhanced anti-tumor efficacy. This work establishes MARCO as a key regulator of MDSC-mediated immunosuppression and presents a compelling case for the inclusion of MARCO as a therapeutic target in cancer immunotherapy.</p>","PeriodicalId":9735,"journal":{"name":"Cell Death Discovery","volume":"11 1","pages":"337"},"PeriodicalIF":6.1000,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cell Death Discovery","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1038/s41420-025-02627-1","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Myeloid-derived suppressor cells (MDSCs) significantly contribute to the immunosuppressive tumor microenvironment (TME), and targeted inhibition of MDSCs is a potential therapeutic strategy against cancer. Here, we identify macrophage receptor with collagenous structure (MARCO) as a critical regulator of MDSC differentiation and immunosuppression in breast cancer. The present study demonstrates that MARCO is expressed on MDSCs, and breast tumor-derived exosomes (TDEs) enriched with macrophage migration inhibitory factor (MIF) promote MDSC differentiation and amplify immunosuppressive activity by up-regulating MARCO. Genetic ablation of MARCO in a murine breast cancer model attenuated tumor growth, accompanied by reduced monocytic MDSCs (M-MDSCs) and total tumor-associated macrophages (TAMs), along with enhanced infiltration of CD8+ T cells and natural killer (NK) cells. Furthermore, we developed a specific MARCO down-regulation-promoting monoclonal antibody that impeded TDE-induced MDSC differentiation and immunosuppression. In vivo, MARCO down-regulating antibody suppressed tumor growth and reprogrammed the TME by diminishing immunosuppressive MDSCs and TAMs and revitalizing CD8+ T cells and NK cells. Strikingly, combining the MARCO down-regulating antibody with PD-1 blockade synergistically enhanced anti-tumor efficacy. This work establishes MARCO as a key regulator of MDSC-mediated immunosuppression and presents a compelling case for the inclusion of MARCO as a therapeutic target in cancer immunotherapy.
期刊介绍：
Cell Death Discovery is a multidisciplinary, international, online-only, open access journal, dedicated to publishing research at the intersection of medicine with biochemistry, pharmacology, immunology, cell biology and cell death, provided it is scientifically sound. The unrestricted access to research findings in Cell Death Discovery will foster a dynamic and highly productive dialogue between basic scientists and clinicians, as well as researchers in industry with a focus on cancer, neurobiology and inflammation research. As an official journal of the Cell Death Differentiation Association (ADMC), Cell Death Discovery will build upon the success of Cell Death & Differentiation and Cell Death & Disease in publishing important peer-reviewed original research, timely reviews and editorial commentary.
Cell Death Discovery is committed to increasing the reproducibility of research. To this end, in conjunction with its sister journals Cell Death & Differentiation and Cell Death & Disease, Cell Death Discovery provides a unique forum for scientists as well as clinicians and members of the pharmaceutical and biotechnical industry. It is committed to the rapid publication of high quality original papers that relate to these subjects, together with topical, usually solicited, reviews, editorial correspondence and occasional commentaries on controversial and scientifically informative issues.
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