Pro‐inflammatory chemokine–chemokine receptor interactions within the Ewing sarcoma microenvironment determine CD8+ T‐lymphocyte infiltration and affect tumour progression

• DOI: 10.1002/path.2819
• Publication Date: 2010-11-09T15:43:20Z
• Authors: Dagmar Berghuis; Susy J Santos; Hans J Baelde; Antonie HM Taminiau; R Maarten Egeler; Marco W Schilham; Pancras CW Hogend...; Arjan C Lankester
• Keywords: Adult; Ewing sarcoma bone/soft tissue tumour chemokines infiltrating T-lymphocytes tumour microenvironment immunotherapy quantitative PCR multicolour immunohistochemistry flow cytometry patient prognosis dendritic cells molecular characterization functional-analysis ifn-gamma cancer expression immunotherapy immunity trial interleukin-2; Receptors, CXCR3; Adolescent; Receptors, CCR5; Gene Expression Profiling; Bone Neoplasms; Sarcoma, Ewing; CD8-Positive T-Lymphocytes; Polymerase Chain Reaction; 3. Good health; Neoplasm Proteins; Interferon-gamma; 03 medical and health sciences; Lymphocytes, Tumor-Infiltrating; 0302 clinical medicine; Child, Preschool; Disease Progression; Tumor Cells, Cultured; Tumor Microenvironment; Humans; Receptors, Chemokine; Inflammation Mediators; Child

AbstractEwing 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. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.