title: Granulocytic myeloid-derived suppressor cells are cryosensitive and their frequency does not correlate with serum concentrations of colony-stimulating factors in head and neck cancer.
abstract: Granulocytic myeloid-derived suppressor cells (MDSC) are a MDSC subset expanded in various cancer types. As many clinical studies rely on the use of stored collections of frozen blood samples, we first tested the influence of freezing/thawing procedures on immunophenotyping and enumeration of granulocytic MDSC (G-MDSC). To identify factors involved in expansion of human G-MDSC, we then analyzed correlations between G-MDSC frequencies, clinical parameters and granulocyte-related factors in the peripheral blood of head and neck cancer patients. HLA-DR, CD14, CD33 and CD66b allowed a clear discrimination of G-MDSC from monocytic MDSC and immature myeloid cells. MDSC subsets were sensitive to cryopreservation with immature G-MDSC showing the highest sensitivity. G-MDSC frequencies were increased in advanced disease stage and associated with the level of CCL4 and CXCL8, but not with colony-stimulating factors, IL-6, S100A8/9, CXCL1 and other cytokines. Our results indicate that the frequency of MDSC, in particular G-MDSC, may be underestimated in retrospective clinical analyses using frozen blood samples. Increased G-MDSC frequencies correlate with advanced disease and increased concentrations of CXCL8, but, unexpectedly, not with growth factors (such as granulocyte colony-stimulating factor), IL-6 and CXCL1. Our data suggest that CXCL8 promotes accumulation of G-MDSC in cancer patients independent of classical colony-stimulating factors.
authors.affiliation: Department of Otorhinolaryngology, University Hospital Essen, 45122 Essen, Germany.
authors.forename: Sokratis
authors.initials: S
authors.lastname: Trellakis
authors.forename: Kirsten
authors.initials: K
authors.lastname: Bruderek
authors.forename: Jan
authors.initials: J
authors.lastname: Hütte
authors.forename: Motaz
authors.initials: M
authors.lastname: Elian
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Hoffmann
authors.forename: Stephan
authors.initials: S
authors.lastname: Lang
authors.forename: Sven
authors.initials: S
authors.lastname: Brandau
mesh_terms: D015703:Antigens, CD / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D054407:Chemokine CCL4 / Q000378:metabolism; D003115:Colony-Stimulating Factors / Q000097:blood; D015925:Cryopreservation / Q000379:methods*; D006098:Granulocytes / Q000473:pathology; D006684:HLA-DR Antigens / Q000378:metabolism; D006258:Head and Neck Neoplasms / Q000276:immunology*; D006801:Humans; D007165:Immunosuppression Therapy; D016209:Interleukin-8 / Q000378:metabolism; D022423:Myeloid Cells / Q000276:immunology* / Q000473:pathology
chemical_list: D015703:Antigens, CD; D054407:Chemokine CCL4; D003115:Colony-Stimulating Factors; D006684:HLA-DR Antigens; D016209:Interleukin-8