CXCR2 inhibition in G-MDSCs enhances CD47 blockade for melanoma tumor cell clearance

• 成果类型: Article
• 署名作者: Banuelos, Allison; Zhang, Allison; Berouti, Hala; Baez, Michelle; Yilmaz, Leyla; Georgeos, Nardin; Marjon, Kristopher D.; Miyanishi, Masanori; Weissman, Irving L.
• 署名单位: Stanford University; Stanford University; Kobe University; Stanford University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8897
• DOI: 10.1073/pnas.2318534121
• 发表日期: 2024-01-30
• 关键词: suppressor-cells; infiltrating macrophages; cancer; immunotherapy; antibody; expression; target; thioglycolate; osteopetrosis; phagocytosis

摘要

The use of colony- stimulating factor - 1 receptor (CSF1R) inhibitors has been widely explored as a strategy for cancer immunotherapy due to their robust depletion of tumor- associated macrophages (TAMs). While CSF1R blockade effectively eliminates TAMs from the solid tumor microenvironment, its clinical efficacy is limited. Here, we use an inducible CSF1R knockout model to investigate the persistence of tumor progression in the absence of TAMs. We find increased frequencies of granulocytic myeloid- derived suppressor cells (G- MDSCs) in the bone marrow, throughout circulation, and in the tumor following CSF1R deletion and loss of TAMs. We find that G-MDSCs are capable of suppressing macrophage phagocytosis, and the elimination of G-MDSCs through CXCR2 inhibition increases macrophage capacity for tumor cell clearance. Further, we find that combination therapy of CXCR2 inhibition and CD47 blockade synergize to elicit a significant anti - tumor response. These findings reveal G-MDSCs as key drivers of tumor immunosuppression and demonstrate their inhibition as a potent strategy to increase macrophage phagocytosis and enhance the anti - tumor efficacy of CD47 blockade in B16 - F10 melanoma.