title: Expansion of human T regulatory type 1 cells in the microenvironment of cyclooxygenase 2 overexpressing head and neck squamous cell carcinoma.
abstract: Cyclooxygenase 2 (COX-2) overexpression and production of prostaglandin E(2) (PGE(2)) by head and neck squamous cell carcinomas (HNSCC) induce type 1 regulatory T (Tr1) cells and contribute to carcinogenesis by creating a tolerogenic milieu. To test this hypothesis, CD4(+)CD25(-) T cells obtained from the peripheral blood of 10 normal donors were cocultured with autologous dendritic cells, irradiated HNSCC cells and cytokines, interleukin 2 (IL-2), IL-10, and IL-15. HNSCC cells were either COX-2 negative, constitutively expressed COX-2, were transfected with COX-2, or had COX-2 expression knocked down by small interfering RNA. Other modifications included coculture plus or minus the COX-inhibitor, Diclofenac, or synthetic PGE(2) in the absence of HNSCC. Lymphocytes proliferating in 10-day cocultures were phenotyped by flow cytometry, studied for cytokine production by ELISA and for suppressor function in CFSE inhibition assays plus or minus anti-IL-10 or anti-transforming growth factor-beta(1) (TGF-beta(1)) monoclonal antibodies (mAb). COX-2(+) HNSCC or exogenous PGE(2) induced outgrowth of Tr1 cells with the CD3(+)CD4(+)CD25(-)IL2Rbeta(+)IL2Rgamma(+)FoxP3(+)CTLA-4(+)IL-10(+)TGF-beta(1)(+)IL-4(-) phenotype and high suppressor functions (range, 46-68%). Small interfering RNA knockout of COX-2 gene in HNSCC led to outgrowth of lymphocytes with decreased IL2Rgamma (P = 0.0001), FoxP3 (P = 0.05), and IL-10 (P = 0.035) expression and low suppressor activity (range, 26-34%). Whereas COX-2(+) cocultures contained IL-10 and TGF-beta(1) (medians, 615 and 824 pg/mL), cytokine levels were decreased (P < 0.0001) in COX-2(-) cocultures. Inhibition of COX-2 enzymatic activity in HNSCC abrogated outgrowth of Tr1 cells. Neutralizing mAbs to IL-10 and/or TGF-beta(1) abolished Tr1-mediated suppression. COX-2 overexpression in HNSCC plays a major role in the induction of Tr1 cells in the tumor microenvironment.
authors: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, USA.
authors: Christoph
authors: C
authors: Bergmann
authors: Laura
authors: L
authors: Strauss
authors: Reinhard
authors: R
authors: Zeidler
authors: Stephan
authors: S
authors: Lang
authors: Theresa L
authors: TL
authors: Whiteside
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000201:enzymology / Q000276:immunology; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000235:genetics / Q000276:immunology*; D045744:Cell Line, Tumor; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D006258:Head and Neck Neoplasms / Q000201:enzymology / Q000235:genetics / Q000276:immunology*; D006801:Humans; D016753:Interleukin-10 / Q000037:antagonists & inhibitors; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D008213:Lymphocyte Activation; D034741:RNA, Small Interfering / Q000235:genetics; D020123:Sirolimus / Q000494:pharmacology; D050378:T-Lymphocytes, Regulatory / Q000201:enzymology / Q000276:immunology*; D014162:Transfection; D053773:Transforming Growth Factor beta1 / Q000037:antagonists & inhibitors
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016207:Cytokines; D053645:Interleukin-2 Receptor alpha Subunit; D034741:RNA, Small Interfering; D053773:Transforming Growth Factor beta1; D016753:Interleukin-10; D051546:Cyclooxygenase 2; D020123:Sirolimus