{ "abstract": "Introduction: Myeloid-derived suppressor cells (MDSCs) regulate immune responses, but their role in autoimmune diseases such as rheumatoid arthritis (RA) remains incompletely understood. Here, we applied non-invasive positron emission tomography (PET) imaging to investigate the migration dynamics of polymorphonuclear (PMN)-MDSCs in experimental RA.\n\nMaterials and methods: RA was induced in female BALB/c mice via K/BxN serum. Immune infiltrates in arthritic ankles were characterized by flow cytometry and liquid chromatography–mass spectrometry (LC–MS)-based proteomics. We radiolabeled bone marrow-derived (BM-PMN-MDSCs) and RA ankle-derived PMN-MDSCs (RA-PMN-MDSCs) intracellularly with [ ⁶⁴ Cu]Cu-PTSM or Ly6G-specific [ ⁶⁴ Cu]Cu-NOTA-1A8. Radiolabeled PMN-MDSCs were adoptively transferred into RA mice and tracked longitudinally by PET/MRI. In a second cohort, [ ⁶⁴ Cu]Cu-NOTA-1A8 was injected directly for in vivo imaging of Ly6G ⁺ myeloid cells over 48 h.\n\nResults: RA progression was associated with a marked increase in the number of CD11b ⁺ Ly6C med Ly6G ⁺ PMN-MDSCs in arthritic ankles, whereas the number of CD11b ⁺ Ly6C high Ly6G ⁻ monocytic-MDSCs remained unchanged. PET/MRI demonstrated significantly enhanced homing of RA-PMN-MDSCs to inflamed ankles compared with that of BM-PMN-MDSCs, indicating disease-associated functional adaptation. Direct in vivo targeting of MDSCs with [ ⁶⁴ Cu]Cu-1A8 revealed strongly increased uptake in arthritic ankles at 1 h, 24 h, and 48 h p.i. , which was significantly reduced by Ly6G blockade, confirming tracer specificity. Proteomic analysis revealed enrichment of extracellular matrix organization and integrin signaling pathways in RA-PMN-MDSCs, suggesting that a distinct inflammatory signature underlies their migratory behavior.\n\nConclusion: PET/MRI enables non-invasive monitoring of PMN-MDSC migration during experimental RA and provides novel insights into the role of these cells in autoimmune inflammation, supporting the development of PMN-MDSCs as biomarkers and therapeutic targets in autoimmune diseases.", "abstract_shown": true, "affiliations": [ "Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University", "Department of Nuclear Medicine and Clinical Molecular Imaging, Eberhard Karls University", "Cluster of Excellence iFIT (EXC 2180) “Image-Guided and Functionally Instructed Tumor Therapies”, Eberhard Karls University", "Medical Proteome Center, Division for Experimental Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University", "Department of Pediatrics, Eberhard Karls University", "Department of Dermatology, Eberhard Karls University", "Institute of Pathology and Neuropathology, Eberhard Karls University", "Core Facility Histology, Faculty of Medicine, University Hospital Tübingen, Eberhard Karls University Tübingen", "Department of Internal Medicine 2, University of Tubingen" ], "article_type": "research article", "arxiv": null, "author_total": 17, "authors": [ { "affs": [ 0, 1, 2 ], "name": "Johannes Schwenck" }, { "affs": [ 0 ], "name": "Kerstin Fuchs" }, { "affs": [ 0, 3 ], "name": "Mohamed Ali Jarboui" }, { "affs": [ 0 ], "name": "Sophia Geiger" }, { "affs": [ 0 ], "name": "Marc Neumann" }, { "affs": [ 4 ], "name": "Hasan H. Öz" }, { "affs": [ 4, 5 ], "name": "Melanie Carevic" }, { "affs": [ 0 ], "name": "Sabrina Hoffmann" }, { "affs": [ 4 ], "name": "Dominik Hartl" }, { "affs": [ 0 ], "name": "Christoph M. Griessinger" }, { "affs": [ 6, 7 ], "name": "Irene Gonzalez-Menendez" }, { "affs": [ 2, 6, 7 ], "name": "Leticia Quintanilla-Martinez" }, { "affs": [ 8 ], "name": "Jörg Henes" }, { "affs": [ 0 ], "name": "Gerald Reischl" }, { "affs": [ 0, 2 ], "name": "Andreas Maurer" }, { "affs": [ 0, 2 ], "name": "Bernd J. Pichler" }, { "affs": [ 0, 2, 5 ], "name": "Manfred Kneilling" } ], "bibtex": "https://research.draconitic.com/paper/7ra8phs5henx2.bib", "cited_by": 0, "doi": "10.3389/fimmu.2026.1909885", "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13716723/?tool=EBI", "id": "7ra8phs5henx2", "issns": [ "1664-3224" ], "landing_url": "https://www.frontiersin.org/articles/10.3389/fimmu.2026.1909885/full", "language": "eng", "licence": "CC-BY-4.0", "licence_label": "CC BY 4.0", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "Original Research" ], [ "openalex", "2745|Rheumatoid Arthritis Research and Therapies" ] ], "openalex": "W7222134473", "pdf_url": "https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2026.1909885/pdf", "pmcid": "PMC13716723", "pmid": "42959266", "published": "2026-10-15", "publisher": "Frontiers Media SA", "ris": "https://research.draconitic.com/paper/7ra8phs5henx2.ris", "sources": [ { "first_seen": "2026-10-30T12:19:17Z", "native_id": "10.3389/fimmu.2026.1909885", "source": "crossref", "url": "https://www.frontiersin.org/articles/10.3389/fimmu.2026.1909885/full" }, { "first_seen": "2026-10-31T00:20:37Z", "native_id": "PMC:PMC13716723", "source": "europepmc", "url": "https://europepmc.org/article/PMC/PMC13716723" }, { "first_seen": "2026-11-01T00:20:52Z", "native_id": "MED:42959266", "source": "europepmc", "url": "https://europepmc.org/article/MED/42959266" }, { "first_seen": "2026-11-01T12:23:56Z", "native_id": "PMC13716723", "source": "pmc", "url": "https://doi.org/10.3389/fimmu.2026.1909885" } ], "subjects": [ { "field": "biology", "origin": "issn:1664-3224", "subfield": "immunology" } ], "title": "In vivo monitoring of polymorphonuclear myeloid-derived suppressor cells in experimental rheumatoid arthritis", "title_text": "In vivo monitoring of polymorphonuclear myeloid-derived suppressor cells in experimental rheumatoid arthritis", "type": "peer-reviewed", "updated_at": "2026-11-02T12:21:10Z", "url": "https://research.draconitic.com/paper/7ra8phs5henx2", "venue": "Frontiers in Immunology", "versions": [] }