Supplementary Figure 5: Phagosomal rupture assay using the CCF4/β-lactamase system.

Wild-type, Ifnar1–/– and Gbpchr3-deleted BMDMs were primed for 16 h with IFN-β (500 units/ml), infected for 1 h with wild-type F. novicida (FN) U112, a β-lactamase-deficient mutant (Δbla) or a ΔFPI mutant and loaded with CCF4-AM for 1 h before analysis by flow cytometry. Phagosomal rupture is associated with β-lactamase (encoded by FTN_1072) release into the cytosol and cleavage of the CCF4 substrate (maximum emission at 520 nm) into a product which emits with a maximum of fluorescence at 447 nm. FACS plots show pooled data from three independent samples and representative of three independent experiments. Live cells (propidium iodide negative) are shown.