(C-F) Role of the Lqs system for LCV escape and cytosolic localization of L. pneumophila. (C, D) A. castellanii or (E, F) D. discoideum was infected (MOI 5, 48 h) with L. pneumophila JR32, ∆lqsA, ∆lqsR, ∆lqsS, ∆lqsT, or ∆lqsS-∆lqsT harboring Ptac-mCherry-PflaA-gfp, fixed and treated with an anti‐ubiquitin antibody. Amoebae containing bacteria decorated with ubiquitin were quantified by confocal microscopy. Representative images of (C) A. castellanii (scale bars: 10 µm) or (E) D. discoideum (scale bars: 5 μm) infected with L. pneumophila JR32 escaping or not from the LCV are shown. The percentage of amoebae containing ubiquitinated bacteria was quantified by counting the total number of infected cells and the number of ubiquitinated cells: (D) JR32: n = 482; ΔlqsA: n = 834; ΔlqsR: n = 572; ΔlqsS: n = 729; ΔlqsT: n = 1469; ΔlqsS-ΔlqsT: n = 693; (F): JR32: n = 136; ΔlqsA: n = 201; ΔlqsR: n = 303; ΔlqsS: n = 183; ΔlqsT: n = 534; ΔlqsS-ΔlqsT: n = 180. 