Salmonella Typhimurium effector SseI inhibits chemotaxis and increases host cell survival by deamidation of heterotrimeric Gi proteins
Fig 4
Effects of SseI on host cell survival.
(A and B) RAW264.7 macrophages were infected with wild type (wt) or ΔsseI-Salmonella (MOI = 30; 30 min). 1.5 h p.i., cells were starved for 3.5 h in Earle’s balanced salt solution. The PI3K inhibitor LY29 (30 μM) was added 1.5 h p.i. where indicated. (A) The amount of LDH released into the medium was measured fluorometrically 5 h p.i.. ΔsseI-infected macrophages showed higher amounts of released LDH compared to wt-Salmonella infected cells. Data show means ±SEM from 3 independent experiments. Maximum LDH-release was obtained in the presence of 1% Triton X-100. Statistical significance was assessed using ANOVA (Bonferroni post-test). (B) Viability of RAW264.7 macrophages was fluorometrically measured 5 h p.i. by the ability of cells to reduce Resorufin. Experiments were performed in triplicates. Values are means ±SEM from at least 3 independent experiments. Statistical significance was assessed using ANOVA (Bonferroni post-test).