Vienot et al. used bulk and scRNA sequencing to investigate the role of TGF-β1 in treatment resistance and how it contributes to an immunosuppressive TME. In several syngeneic mouse models, TGF-β1 inhibition, combined with immunogenic chemotherapy (FOLFOX; 5-fluorouracil and oxaliplatin) and anti-PD-1, resulted in CD8+ T cell recruitment into tumors and superior efficacy with long-term memory. Mechanistically, TGF-β1 inhibition was critical for a switch in epigenetic chromatin remodeling of CXCL9 and CXCL10 in iCAF, leading to increased CXCL9/10 production and decreased CXCL14 and homing of antigen-specific T cells to the TME.
Contributed by Katherine Turner
ABSTRACT: Combining immunogenic cell death-inducing chemotherapies and PD-1 blockade can generate remarkable tumor responses. It is now well established that TGF-β1 signaling is a major component of treatment resistance and contributes to the cancer-related immunosuppressive microenvironment. However, whether TGF-β1 remains an obstacle to immune checkpoint inhibitor efficacy when immunotherapy is combined with chemotherapy is still to be determined. Several syngeneic murine models were used to investigate the role of TGF-β1 neutralization on the combinations of immunogenic chemotherapy (FOLFOX: 5-fluorouracil and oxaliplatin) and anti-PD-1. Cancer-associated fibroblasts (CAF) and immune cells were isolated from CT26 and PancOH7 tumor-bearing mice treated with FOLFOX, anti-PD-1 ± anti-TGF-β1 for bulk and single cell RNA sequencing and characterization. We showed that TGF-β1 neutralization promotes the therapeutic efficacy of FOLFOX and anti-PD-1 combination and induces the recruitment of antigen-specific CD8+ T cells into the tumor. TGF-β1 neutralization is required in addition to chemo-immunotherapy to promote inflammatory CAF infiltration, a chemokine production switch in CAF leading to decreased CXCL14 and increased CXCL9/10 production and subsequent antigen-specific T cell recruitment. The immune-suppressive effect of TGF-β1 involves an epigenetic mechanism with chromatin remodeling of CXCL9 and CXCL10 promoters within CAF DNA in a G9a and EZH2-dependent fashion. Our results strengthen the role of TGF-β1 in the organization of a tumor microenvironment enriched in myofibroblasts where chromatin remodeling prevents CXCL9/10 production and limits the efficacy of chemo-immunotherapy.
Author Info: (1) Department of Medical Oncology, University Hospital of Besançon, F-25000 Besançon, France. INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions
Author Info: (1) Department of Medical Oncology, University Hospital of Besançon, F-25000 Besançon, France. INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. Clinical Investigational Center, CIC-1431, F-25000 Besançon, France. (2) INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. (3) INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. (4) Department of Medical Oncology, University Hospital of Besançon, F-25000 Besançon, France. INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. (5) INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. ITAC platform, University of Bourgogne Franche-Comté, F-25000 Besançon, France. (6) INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. (7) INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. ITAC platform, University of Bourgogne Franche-Comté, F-25000 Besançon, France. (8) INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. (9) Argenx, 9052 Zwijnaarde, Belgium. (10) Argenx, 9052 Zwijnaarde, Belgium. (11) INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. (12) INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. EPIgenetics and GENe EXPression Technical Platform (EPIGENExp), University of Bourgogne Franche-Comté, F-25000 Besançon, France. (13) INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. EPIgenetics and GENe EXPression Technical Platform (EPIGENExp), University of Bourgogne Franche-Comté, F-25000 Besançon, France. (14) Department of Medical Oncology, University Hospital of Besançon, F-25000 Besançon, France. INSERM, EFS BFC, UMR1098, RIGHT, University of Bourgogne Franche-Comté, Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et Génique, F-25000 Besançon, France. Clinical Investigational Center, CIC-1431, F-25000 Besançon, France. ITAC platform, University of Bourgogne Franche-Comté, F-25000 Besançon, France.
