Publication date: 12 September 2016
Source:Cancer Cell, Volume 30, Issue 3
Author(s): Ilaria Marigo, Serena Zilio, Giacomo Desantis, Bernhard Mlecnik, Andrielly H.R. Agnellini, Stefano Ugel, Maria Stella Sasso, Joseph E. Qualls, Franz Kratochvill, Paola Zanovello, Barbara Molon, Carola H. Ries, Valeria Runza, Sabine Hoves, Amélie M. Bilocq, Gabriela Bindea, Emilia M.C. Mazza, Silvio Bicciato, Jérôme Galon, Peter J. Murray, Vincenzo Bronte
Effective cancer immunotherapy requires overcoming immunosuppressive tumor microenvironments. We found that local nitric oxide (NO) production by tumor-infiltrating myeloid cells is important for adoptively transferred CD8+ cytotoxic T cells to destroy tumors. These myeloid cells are phenotypically similar to inducible nitric oxide synthase (NOS2)- and tumor necrosis factor (TNF)-producing dendritic cells (DC), or Tip-DCs. Depletion of immunosuppressive, colony stimulating factor 1 receptor (CSF-1R)-dependent arginase 1+ myeloid cells enhanced NO-dependent tumor killing. Tumor elimination via NOS2 required the CD40-CD40L pathway. We also uncovered a strong correlation between survival of colorectal cancer patients and NOS2, CD40, and TNF expression in their tumors. Our results identify a network of pro-tumor factors that can be targeted to boost cancer immunotherapies.
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Marigo et al. show that nitric oxide produced by Tip-DCs, a subset of tumor-infiltrating myeloid cells, is important for tumor control by adoptive cell therapy (ACT). Tip-DCs require the CD40-CD40L pathway but not CSF-1R; CSF-1R blockade reduces immunosuppressive macrophages and improves tumor control by ACT.http://ift.tt/2chRk8j