Figure 4.

Actin is not required for invasion of erythrocytes by F. tularensis. Erythrocytes were treated with 50 μg/mL cytochalasin D (Cyt.) for 30 min (A) or 16 μM phalloidin for 20 min (B) prior to infection with F. tularensis LVS and then subjected to a gentamicin protection assay to measure invasion. Wells lacking erythrocytes served as controls. Data are expressed as mean CFU ± SD for at least three independent experiments. For each experiment, we observed significant differences between the same groups. Each iteration contained at least 4 separate wells per group. RBC, red blood cell; Veh, vehicle, chloroform; Cyt, cytochalasin D.