title: Avoiding phagocytosis-related artifact in myeloid derived suppressor cell T-lymphocyte suppression assays.
abstract: Myeloid-derived suppressor cells (MDSCs) have garnered much attention in recent years as a potential target for altering the immunosuppressive tumor microenvironment in a variety of solid tumor types. The ability to accurately assess the immunosuppressive capacity of MDSCs is fundamental to the development of therapeutic approaches aimed at disabling these immunosuppressive functions. In this article we provide evidence that the use of CD3/28 coated microbeads leads to artefactual T-lymphocyte suppression due to sequestration of beads by MDSCs isolated from the spleens of wild-type mice bearing subcutaneous syngeneic, carcinogen-induced oral cavity carcinomas. Mechanisms of this finding may include early MDSC death and acquisition of phagocytic capacity. These artefactual findings were avoided by eliminating the use of microbeads and instead using plate bound CD3/28 antibody as the T-lymphocyte stimulus. We propose model-specific validation of microbead-based MDSC assays, or use of an alternative stimulation approach such as plate bound CD3/28 antibodies.
authors.affiliation: Tumor Biology Section, Head and Neck Surgery Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States.
authors.forename: Ruth J
authors.initials: RJ
authors.lastname: Davis
authors.affiliation: Tumor Biology Section, Head and Neck Surgery Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Silvin
authors.affiliation: Tumor Biology Section, Head and Neck Surgery Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States; Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD, United States. Electronic address: clint.allen@nih.gov.
authors.forename: Clint T
authors.initials: CT
authors.lastname: Allen
mesh_terms: D000818:Animals; D016477:Artifacts; D018106:CD28 Antigens / Q000276:immunology / Q000378:metabolism; D017252:CD3 Complex / Q000276:immunology / Q000378:metabolism; D016923:Cell Death; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D005434:Flow Cytometry; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed / Q000379:methods*; D008810:Mice, Inbred C57BL; D009062:Mouth Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D000072737:Myeloid-Derived Suppressor Cells / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D010587:Phagocytosis; D015203:Reproducibility of Results; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D013997:Time Factors; D019139:Tumor Escape; D059016:Tumor Microenvironment
chemical_list: D018106:CD28 Antigens; D017252:CD3 Complex
keywords: Artifact; CD3/28 microbeads; MDSC; Myeloid-derived suppressor cells; Phagocytosis; T-cell suppression assay