Myeloid cell coagulation factor Xa-protease activated receptor 2 signaling inhibition expands progenitor exhausted T-cells in the tumor microenvironment

Coagulation protease signaling within the tumor-microenvironment (TME) causes cancer immune evasion and impairs immune checkpoint-inhibitor therapy. Tumor-associated macrophages produce factor X and drive immune-evasive protease activated receptor-2 (PAR2) signaling. Myeloid FXa-PAR2 signaling promotes the enrichment of resident-like macrophages displaying an immunosuppressive repair phenotype within the TME of mice with genetically induced spontaneous breast cancer development. Conversely, loss of FXa-PAR2 signaling favors the expansion of monocyte-derived macrophage subsets relevant for DNA-sensing, autophagy and cGAS-STING-IFNβ mediated stimulation of anti-tumor immunity. Thereby FXa suppresses the function of CD103+ dendritic cells relevant for priming, reactivation, and expansion of CD8+ T-cells, including antigen-experienced progenitor exhausted T-cells. Our findings thus emphasize the translational potential of FXa inhibition to synergize with immunotherapy.ompacted abstract CD11c+ cells or T cells from the TME of wild-type vs Fxa-PAR2 signaling deficient (PAR2 G37I) mice were processed for single-cell sequencing on the 10x Genomics platform