(A, B) Role of the Lqs system for PflaA expression in intracellular L. pneumophila. A. castellanii was infected (MOI 5, 48 h) with L. pneumophila JR32, ∆lqsA, ∆lqsR, ∆lqsS, ∆lqsT, or ∆lqsS-∆lqsT harboring Ptac-mCherry-PflaA-gfp, and (A) fixed and analyzed by confocal microscopy (representative 3D reconstructions, scale bars: 10 µm), or (B) lysed, fixed and analyzed by flow cytometry. 