1. The CCL2-CCR4 axis promotes Regulatory T cell trafficking to canine glioma tissues
- Author
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Panek, WK, Toedebusch, RG, Mclaughlin, BE, Dickinson, PJ, Van Dyke, JE, Woolard, KD, Berens, ME, Lesniak, MS, Sturges, BK, Vernau, KM, Li, C, Miska, J, and Toedebusch, Christine M
- Subjects
Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Immunology ,Immunotherapy ,Brain Cancer ,Cancer ,Brain Disorders ,Rare Diseases ,Neurosciences ,2.1 Biological and endogenous factors ,Dogs ,Animals ,Receptors ,CCR4 ,T-Lymphocytes ,Regulatory ,Glioma ,Chemokine CCL2 ,Brain Neoplasms ,Cell Line ,Tumor ,Cell Movement ,Humans ,Dog ,Glioblastoma ,Tumor-infiltrating lymphocyte ,CCL2 ,CCR4 ,Oncology & Carcinogenesis ,Oncology and carcinogenesis - Abstract
PurposeSpontaneously occurring glioma in pet dogs is increasingly recognized as a valuable translational model for human glioblastoma. Canine high-grade glioma and human glioblastomas share many molecular similarities, including the accumulation of immunosuppressive regulatory T cells (Tregs) that inhibit anti-tumor immune responses. Identifying in dog mechanisms responsible for Treg recruitment may afford to target the cellular population driving immunosuppression, the results providing a rationale for translational clinical studies in human patients. Our group has previously identified C-C motif chemokine 2 (CCL2) as a glioma-derived T-reg chemoattractant acting on chemokine receptor 4 (CCR4) in a murine orthotopic glioma model. Recently, we demonstrated a robust increase of CCL2 in the brain tissue of canine patients bearing high-grade glioma.MethodsWe performed a series of in vitro experiments using canine Tregs and patient-derived canine glioma cell lines (GSC 1110, GSC 0514, J3T-Bg, G06A) to interrogate the CCL2-CCR4 signaling axis in the canine.ResultsWe established a flow cytometry gating strategy for identifying and isolating FOXP3+ Tregs in dogs. The canine CD4 + CD25high T-cell population was highly enriched in FOXP3 and CCR4 expression, indicating they are bona fide Tregs. Canine Treg migration was enhanced by CCL2 or by glioma cell line-derived supernatant. Blockade of the CCL2-CCR4 axis significantly reduced migration of canine Tregs. CCL2 mRNA was expressed in all glioma cell lines, and expression increased when exposed to Tregs but not CD4 + helper T-cells.ConclusionOur study validates CCL2-CCR4 as a bi-directional Treg-glioma immunosuppressive and tumor-promoting axis in canine high-grade glioma.
- Published
- 2024