Extracellular vesicles derived from nasopharyngeal carcinoma induce the emergence of mature regulatory dendritic cells using a galectin‐9 dependent mechanism

• Published in: Journal of extracellular vesicles Vol. 12; no. 12; pp. e12390 - n/a
• Main Authors: Lefebvre, Anthony, Trioën, Camille, Renaud, Sarah, Laine, William, Hennart, Benjamin, Bouchez, Clément, Leroux, Bertrand, Allorge, Delphine, Kluza, Jérôme, Werkmeister, Elisabeth, Grolez, Guillaume Paul, Delhem, Nadira, Moralès, Olivier
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.12.2023; Wiley; John Wiley and Sons Inc
• Series: Journal of extracellular vesicles
• Subjects: Antigens; Antitumor activity; Cancer; Cell cycle; Cell proliferation; Dendritic Cells; Epstein-Barr virus; Extracellular Vesicles; Fatty acids; Galectins - metabolism; galectin‐9; Humans; IDO; IL4I1; IL‐4; Immunotherapy; Life Sciences; Lymphocytes; Lymphocytes T; mature regulatory dendritic cells; Medical prognosis; Metabolism; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms - metabolism; Oxidation; Oxidative metabolism; Phenotypes; Phosphorylation; Tumor Microenvironment; IL4I1; nasopharyngeal carcinoma; extracellular vesicles; IDO; galectin-9; IL-4; mature regulatory dendritic cells; metabolism; Mesh:Dendritic Cells; Mesh:Nasopharyngeal Neoplasms/metabolism; Mesh:Tumor Microenvironment; Mesh:Humans; Mesh:Extracellular Vesicles; Mesh:Galectins/metabolism; Mesh:Nasopharyngeal Carcinoma
• ISSN: 2001-3078; 2001-3078
• DOI: 10.1002/jev2.12390

Nasopharyngeal carcinoma‐derived small extracellular vesicles (NPCSEVs) have an immunosuppressive impact on the tumour microenvironment. In this study, we investigated their influence on the generation of tolerogenic dendritic cells and the potential involvement of the galectin‐9 (Gal9) they carry in this process. We analysed the phenotype and immunosuppressive properties of NPCSEVs and explored the ability of DCs exposed to NPCSEVs (NPCSEV‐DCs) to regulate T cell proliferation. To assess their impact at the pathophysiological level, we performed real‐time fluorescent chemoattraction assays. Finally, we analysed phenotype and immunosuppressive functions of NPCSEV‐DCs using a proprietary anti‐Gal9 neutralising antibody to assess the role of Gal9 in this effect. We described that NPCSEV‐DCs were able to inhibit T cell proliferation despite their mature phenotype. These mature regulatory DCs (mregDCs) have a specific oxidative metabolism and secrete high levels of IL‐4. Chemoattraction assays revealed that NPCSEVs could preferentially recruit NPCSEV‐DCs. Finally, and very interestingly, the reduction of the immunosuppressive function of NPCSEV‐DCs using an anti‐Gal9 antibody clearly suggested an important role for vesicular Gal9 in the induction of mregDCs. These results revealed for the first time that NPCSEVs promote the emergence of mregDCs using a galectin‐9 dependent mechanism and open new perspectives for antitumour immunotherapy targeting NPCSEVs.