Differential response of myeloid-derived suppressor cells to the nonsteroidal anti-inflammatory agent indomethacin in tumor-associated and tumor-free microenvironments.
Myeloid-derived suppressor cells (MDSCs) are key regulatory cells that control inflammation and promote tumor-immune escape. To date, no specific immunomodulatory drug has proven efficacy in targeting the expansion and/or function of these cells in different pathophysiologic settings. In this study, we identified a context-dependent effect of the nonsteroidal anti-inflammatory drug indomethacin (IND) on MDSCs, depending on whether they were derived from tumor microenvironments (TME) or from tumor-free microenvironments (TFME). Treatment of mice bearing the LP07 lung adenocarcinoma with IND inhibited the suppressive activity of splenic MDSCs, which restrained tumor growth through mechanisms involving CD8(+) T cells. The same effect was observed when MDSCs were treated with IND and conditioned media from LP07 tumor cells in vitro. However, in the absence of a tumor context, IND enhanced the intrinsic suppressive function of MDSCs and amplified their protumoral activity. In a model of autoimmune neuroinflammation, IND-treated MDSCs differentiated in TFME attenuated inflammation, whereas IND-treated MDSCs differentiated in TME aggravated clinical symptoms and delayed resolution of the disease. Mechanistically, IND reduced arginase activity as well as NO and reactive oxygen species production in MDSCs differentiated in TME but not in TFME. Moreover, expression of the C/EBP-β transcription factor isoforms correlated with the suppressive activity of IND-treated MDSCs. Our study unveils the dual and context-dependent action of IND, a drug that serves both as an anti-inflammatory and anticancer agent, which differentially affects MDSC activity whether these cells are derived from TME or TFME. These results have broad clinical implication in cancer, chronic inflammation and autoimmunity.
Área Investigación, Instituto de Oncología Ángel H. Roffo, Universidad de Buenos Aires, C1427 Buenos Aires, Argentina; Laboratorio de Inmunopatología, Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428 Buenos Aires, Argentina; and.
Ada G
AG
Blidner
Laboratorio de Inmunopatología, Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428 Buenos Aires, Argentina; and.
Mariana
M
Salatino
Laboratorio de Inmunopatología, Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428 Buenos Aires, Argentina; and.
Ivan D
ID
Mascanfroni
Área Investigación, Instituto de Oncología Ángel H. Roffo, Universidad de Buenos Aires, C1427 Buenos Aires, Argentina;
Miriam J
MJ
Diament
Área Investigación, Instituto de Oncología Ángel H. Roffo, Universidad de Buenos Aires, C1427 Buenos Aires, Argentina;
Elisa
E
Bal de Kier Joffé
Área Investigación, Instituto de Oncología Ángel H. Roffo, Universidad de Buenos Aires, C1427 Buenos Aires, Argentina;
Maria A
MA
Jasnis
Área Investigación, Instituto de Oncología Ángel H. Roffo, Universidad de Buenos Aires, C1427 Buenos Aires, Argentina;
Slobodanka M
SM
Klein
Laboratorio de Inmunopatología, Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428 Buenos Aires, Argentina; and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428 Buenos Aires, Argentina. gabyrabi@gmail.com.
Gabriel A
GA
Rabinovich
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D015551:Autoimmunity / Q000187:drug effects; D060833:Cellular Microenvironment / Q000187:drug effects* / Q000276:immunology*; D004195:Disease Models, Animal; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology / Q000378:metabolism; D005260:Female; D016130:Immunophenotyping; D007213:Indomethacin / Q000494:pharmacology*; D051379:Mice; D008954:Models, Biological; D022423:Myeloid Cells / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D009369:Neoplasms / Q000276:immunology / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism; D010641:Phenotype; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D047368:Tumor Burden / Q000187:drug effects / Q000276:immunology; D059016:Tumor Microenvironment / Q000187:drug effects* / Q000276:immunology*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D007213:Indomethacin