CFL1 and infection: WT macrophages were infected with a T4SS (dotA−) and a flagellin (flaA−) mutant of Legionella. After 1, 2, and 4 hrs of infection, Western blot analysis showed that the dotA− and the flaA− mutants failed to modulate cofilin phosphorylation status when compared to the parental Legionella strain (Fig. 5c).