Fig. 4: Lack of caspase 8 expression initiates early immunosuppressive inflammation which promotes metastasis.

a Representative images of histological analysis (H&E) and immunostaining (CD45) of lungs of RP (n = 4) and RPC (n = 7) mice 2 weeks post Ad-Cre inhalation. Scale bars represent 100 μm. b qPCR analysis of whole lungs 2 weeks post Ad-Cre inhalation (RP n = 3 and RPC n = 5). RPC expression data were normalized to the housekeeping gene actin and plotted as fold increase compared to RP. Data are presented as mean values ± SEM. 12 weeks post Ad-Cre inhalation, immune cells were isolated from whole lungs of RP (n = 7) and RPC (n = 6) mice followed by FACS analysis. Proportions of c M2 macrophages (CD11b⁺CD206⁺) d Tregs (CD4⁺CD25⁺foxp3⁺) within CD45⁺ cells. e TGF-beta ELISA of protein extracts from whole lungs of RP (n = 4) and RPC (n = 4) mice 18 weeks post Ad-Cre inhalation. Data are presented as mean values ± SEM. f 12 weeks post Ad-Cre inhalation, RP and RPC mice were treated either with IgG [5 mg/kg] or anti-CTLA-4 [5 mg/kg] every other day for two weeks. RP IgG (n = 6), RPC IgG (n = 8), RP anti-CTLA-4 (n = 8) and RPC anti-CTLA-4 (n = 12). Tumor incidence was determined by time of first detection in MRI imaging until humane endpoint. g Metastasis incidence based on macroscopical analysis at humane endpoint. h Kaplan–Meier survival of the indicated genotypes after IgG or anti-CTLA-4 treatment. i Treated mice were sacrificed at humane endpoint. Representative photos and quantification of number of macroscopic nodules per lung of mice are shown. b–e Two-tailed unpaired t tests. g, i Fisher´s exact test (two-sided), h, f Mantel-Cox test. Source Data are provided as a Source Data file.