Figure 3

Complementation of SIF biogenesis. HeLa cells were infected at an MOI ≈ 100 with the indicated strains for 8 hours prior to cell fixation. Cells were immunostained for Salmonela (red) and LAMP1 (green), and the nucleus was stained with DAPI (blue). 60 distinct fields of view were used for quantification with at least 1 infected cell per field of view for each experiment. (a–g) Quantification of LAMP1⁺-tubule frequency (SIFs) in HeLa cells infected with single effector deletion mutants in the T3SS2⁺ background and their corresponding complemented strains after 8 h of infection. The average frequency of infected cells with LAMP1⁺-tubules ± standard error of the mean is shown (n = 3). Strains were analyzed in a single repeated experiment but have been divided into separate panels for the sake of clarity. At least 60 infected cells per strain were blindly analyzed in each experiment. p-values are as indicated as determined by two-tailed Mann–Whitney test with a 95% confidence level. (h) Representative images for select strains. White boxes indicate zoomed-in region in inset. Arrowheads indicate LAMP1⁺-tubules. Scale Bar = 10 µm.