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A Three-dimensional Thymic Culture System to Generate Murine Induced Pluripotent Stem Cell-derived Tumor Antigen-specific Thymic Emigrants
Published on: August 9, 2019
Immature monocytic cells within tumors differentiate into immunosuppressive cells in resistant tumors to
Sapir Levin1, Madeleine Benguigui1, Bar Manobla1
1Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.
Immune checkpoint inhibitors (ICIs) have improved outcomes in advanced cancers, yet resistance remains a major obstacle. Here, we investigated the role of myeloid cells in shaping the immunosuppressive tumor microenvironment that contributes to ICI resistance. Using mutagenized ICI-sensitive and resistant 4T1 breast cancer clones, we performed single-cell RNA sequencing to characterize immune cell populations post-ICI therapy. We identified monocytic dendritic progenitors (MDPs) and common monocytic progenitors (cMOPs) enriched in sensitive tumors, which may differentiate into immunosuppressive cells in resistant tumors. Analysis of public datasets confirmed the presence of MDP-cMOPs in tumors and blood of patients with breast, lung, and colorectal cancer. We found high expression of CXCR4 and IL6R in MDP-cMOPs, and inhibiting these pathways blocked their recruitment and differentiation. Combined targeting of CXCR4 and IL6 pathway with ICI improved responses in resistant tumors, highlighting MDP-cMOPs as contributors to immunotherapy resistance and potential therapeutic targets.
Immune checkpoint inhibitors (ICIs) have improved outcomes in advanced cancers, yet resistance remains a major obstacle. Here, we investigated the role of myeloid cells in shaping the immunosuppressive tumor microenvironment that contributes to ICI resistance. Using mutagenized ICI-sensitive and resistant 4T1 breast cancer clones, we performed single-cell RNA sequencing to characterize immune cell populations post-ICI therapy. We identified monocytic dendritic progenitors (MDPs) and common monocytic progenitors (cMOPs) enriched in sensitive tumors, which may differentiate into immunosuppressive cells in resistant tumors. Analysis of public datasets confirmed the presence of MDP-cMOPs in tumors and blood of patients with breast, lung, and colorectal cancer. We found high expression of CXCR4 and IL6R in MDP-cMOPs, and inhibiting these pathways blocked their recruitment and differentiation. Combined targeting of CXCR4 and IL6 pathway with ICI improved responses in resistant tumors, highlighting MDP-cMOPs as contributors to immunotherapy resistance and potential therapeutic targets.
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