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.

Chemotherapy Induces Intratumoral Expression of Chemokines in Cutaneous Melanoma, Favoring T-cell Infiltration and Tumor Control

“…Expression of a nonfunctional allele of CCR5 results in decreased survival of patients with melanoma receiving immunotherapy (32). CXCR3 ligands and CCL5 have also been involved in other types of cancer, including colorectal and Ewing's sarcoma (33,34).…”

GLI2 Transcription Factor Mediates Cytokine Cross-talk in the Tumor Microenvironment

“…is a known cytokine serving as an autocrine or paracrine growth factor for tumor and stromal cells, and is a mediator of the complex networks existing between tumor cells and the stromal microenvironment (27)(28)(29)(30). However, the molecular mechanism underlying this cellular event remains (2)) or scramble (Scr) shRNA control in the presence or absence of the GLI2 expression construct.…”

Human HLA-A*02:01/CHM1+ allo-restricted T cell receptor-transgenic CD8+ T cells specifically inhibit Ewing sarcoma growth in vitro and in vivo

“…Some reports indicate that the lessons learned from immunotherapy of melanoma patients could be potentially translated to other solid tumor entities [9]. However, in the pediatric sarcoma setting, tumor immunogenicity remains yet to be determined [4,6,13,14,[22][23][24][25]. The possibility to target tumor cell antigens essential for survival and proliferation, including transcription factors such as CHM1 renders the use of peptide specific T cells is very attractive.…”