title: Pro-inflammatory chemokine-chemokine receptor interactions within the Ewing sarcoma microenvironment determine CD8(+) T-lymphocyte infiltration and affect tumour progression.
abstract: Ewing sarcoma is an aggressive round cell sarcoma with poor patient prognosis, particularly in cases of advanced-stage disease. Dynamic tumor-host immune interations within the tumor microenvironment may polarize in situ immune responses and shape tumor development and/or progression. To gain insight into the nature of tumour-host immune interactions within the Ewing sarcoma microenvironment, the presence and spatial distribution of infiltrating CD8(+) /CD4(+) T-lymphocytes were evaluated in therapy-naive Ewing sarcoma. Expression profiling of 40 different chemokines and several chemokine receptors was performed in therapy-naive tumours and cell lines by qPCR, immunohistochemistry, and flow cytometry. Considerable inter-tumour variation was observed regarding density, type, and distribution of infiltrating T-lymphocytes. Tumour-infiltrating T-cells contained significantly higher percentages of CD8(+) T-lymphocytes as compared to stroma-infiltrating cells, suggesting preferential migration of this T-cell type into tumour areas. Gene expression levels of several type 1-associated, pro-inflammatory chemokines (CXCR3- and CCR5-ligands CXCL9, CXCL10, and CCL5) correlated positively with infiltrating (CD8(+) ) T-lymphocyte numbers expressing corresponding chemokine receptors. Survival analyses demonstrated an impact of tumour-infiltrating, and not stroma-infiltrating, CD8(+) T-lymphocytes on tumour progression. At protein level, both tumour and stromal cells expressed the IFNγ-inducible chemokines CXCL9 and CXCL10. CCR5-ligand CCL5 was exclusively expressed by non-tumoural stromal/infiltrating cells. Together, our results indicate that an inflammatory immune microenvironment with high expression of type 1-associated chemokines may be critical for the recruitment of (CD8(+) ) T-lymphocytes expressing corresponding chemokine receptors. The observed impact of tumour-infiltrating (CD8(+) ) T-lymphocytes is consistent with a role for adaptive anti-tumour immunity in the prevention of Ewing sarcoma progression. Recognition of the merits and exploitation/induction of an inflammatory microenvironment may improve the efficacy of natural immune responses against, and (adoptive) immunotherapeutic approaches for, Ewing sarcoma.
authors.affiliation: Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Berghuis
authors.forename: Susy J
authors.initials: SJ
authors.lastname: Santos
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Baelde
authors.forename: Antonie Hm
authors.initials: AH
authors.lastname: Taminiau
authors.forename: R Maarten
authors.initials: RM
authors.lastname: Egeler
authors.forename: Marco W
authors.initials: MW
authors.lastname: Schilham
authors.forename: Pancras Cw
authors.initials: PC
authors.lastname: Hogendoorn
authors.forename: Arjan C
authors.initials: AC
authors.lastname: Lankester
mesh_terms: D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D020869:Gene Expression Profiling / Q000379:methods; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D007371:Interferon-gamma / Q000096:biosynthesis; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology*; D009363:Neoplasm Proteins / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D019713:Receptors, CCR5 / Q000378:metabolism; D054367:Receptors, CXCR3 / Q000378:metabolism; D019707:Receptors, Chemokine / Q000378:metabolism*; D012512:Sarcoma, Ewing / Q000276:immunology*; D014407:Tumor Cells, Cultured; D059016:Tumor Microenvironment / Q000276:immunology
chemical_list: C515187:CXCR3 protein, human; D018836:Inflammation Mediators; D009363:Neoplasm Proteins; D019713:Receptors, CCR5; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine; D007371:Interferon-gamma