Effect of large genomic islands depletion in the L. pneumophila genome on Rab5 recruitment to the LCV during infection. (a) Schematic representation of the ∆pentuple and single island-depleted strains (adopted from O’Connor et al. [2011]). (b) HeLa-FcγRII cells expressing mRFP-Rab5A were infected with the indicated L. pneumophila Lp02 strains for 1 h at an MOI of 20. After infection, cells were fixed and stained with anti-Legionella antiserum for detection of extracellular bacteria, then permeabilized and further stained with DAPI for detection of intracellular bacteria. RFP-Rab5A–positive LCVs were quantified. Representative data of three independent experiments were presented (100 vacuoles were scored in each experiment). Results are shown as means ± SD. P values are determined using one-way ANOVA with Tukey’s multiple comparisons. ****P < 0.0001. (c) List of L. pneumophila effectors encoded in the island 7a. (d) HeLa-FcγRII cells were transfected without (mock) or with siRNA-targeting Rab7. At 72 h after transfection, the efficacy of siRNA was assessed by IB with the Rab7 antibody. IB with α-tubulin antibody was conducted as an internal control. IB, immunoblotting. Source data are available for this figure: SourceData FS2.