Fig. 7: SIRT2 restricts Shigella infection in cells and in mice model.

A Effect of Sirt2 knockout on S. flexneri intracellular proliferation analyzed by the gentamycin killing assay. MEF Sirt2^+/+ and Sirt2^-/- cells were infected with S. flexneri for 10 min. Intracellular S. flexneri number and MEF cell number were counted at indicated time points to get MOI value. Data are presented as mean ± SEM with three biological replicates (two technical replicates). Statistical evaluation: unpaired two-tailed Student’s t-test. B, C Effect of SIRT2 knockout on S. flexneri intracellular proliferation. MOI were determined after 10 min of infection and the indicated time of incubation in the presence of 50 μg/ml gentamicin in Sirt2^−/− MEF with empty vector or SIRT2 knock-in (KI, B) and in A549 with control or SIRT2 knockdown (C) Data are presented as mean ± SEM (the SEM is very small and hard to see in the figure) with three biological replicates (two technical replicates). Statistical evaluation: unpaired two-tailed Student’s t-test. D A549 control and SIRT2 KD cells were infected with wildtype and IpaJ deletion S. flexneri M90T cells for 10 min, then treated with gentamycin to kill extracellular bacteria. Intracellular S. flexneri number and mammalian cell number were counted to get MOI. Data are presented as mean ± SEM with nine biological replicates. Statistical evaluation: two-way ANOVA. E Recoverable CFU in lung homogenates from 6 to 8-week old Sirt2^+/+ and Sirt2^-/- C57BL/6 J mice intranasally infected with 1 million S. flexneri M90T wildtype strain. Statistical evaluation: unpaired two-tail Student’s t-test. Data are presented as mean ± SEM with three mice per group. LOD, limit of detection. F Cytokine profile in Sirt2^+/+ and Sirt2^−/− mice lung homogenates after intranasal infection with 1 million S flexneri for 2 days. n = 18 (TNFα) or 14 (IL−17Α) biological replicates. Cytokine levels in PBS-challenged mice fell below the detection limit for the experimental setup so were not included in the graph. Data are represented as mean ± SEM. Statistical evaluation: unpaired two-tail Student’s t-test. ***p < 0.001.