Fig. 3.

Sources and kinetics of Type I IFN in the TME during PD-1 inhibition. a and b In vitro assays. Relative expression of Ifnβ1 quantified by qRT-PCR following stimulations of various tumor cell lines or BMDCs and BMMCs with IFNα, IFNγ or LPS. Each dot represents one sample and graphs represent 1 experiment or are the pool of 2 to 3 independent experiments including biological replicates for each experiment. Unpaired t-tests were used to compare 2 groups. ANOVA statistical tests and pairwise comparisons with Bonferroni adjustment were adopted for more than 2 groups. c–h In vivo studies. Flow cytometry sorting of CD45⁺ live fractions from the TME of MCA205WT c–e or MC38 f–h tumors 48 h after 1, 2, 3 or 4 i.p. administrations of anti-PD-1 (or isotype control) mAb. Relative expression of Ifnβ1 c and f and IFN-sensitive gene products d, e, g, h quantified by qRT-PCR. Unpaired t-tests were used to compared transcription levels between the anti-PD-1 and isotype control treated groups for each time point. Each dot represents 1 mouse with 5 mice per time point per experiment. Graphs represent 1 representative experiment out of 2–3 independent experiments (MC38, time points 1 and 2, d, e), 1 experiment (MC38, time points 3 and 4) or are the pool of 2–3 independent experiments c. *p < 0.05, **p < 0.01, n.s.: not significant. Mean ± SEM are represented