Group B Streptococcus Hijacks the Host Plasminogen System to Promote Brain Endothelial Cell Invasion (original) (raw)
Figure 3
Incubation with human plasma increases the ability of GBS to invade and degrade hBMECs.
(A) HBMECs monolayers were infected with 106 GBS CFU (MOI of 10) pre-incubated or not with whole human plasma and bacterial invasion was determined at the indicated time points and expressed in log 10 CFU/mL (left) or in percentage of intracellular bacteria relative to the initial inoculum. (B) HBMEC monolayer were infected with 106 GBS CFU (MOI of 10) in whole human plasma and the plasmin-like activity of GBS cells was assessed as described in Figure 2C (bars are the mean values of plasmin activity + SEM) and the bacterial CFU were determined at the same time points (line represents the mean numbers of bacterial CFU ± SEM). (C) HBMECs monolayers were infected with 106 GBS CFU (MOI of 10) preincubated (GBS + εACA) or not (GBS) with 200 mM εACA in whole human plasma for a 300 min period at 37°C. The acquisition of cell surface plasmin activity was detected as described in Figure 2C and results are the mean values + SEM of the plasmin activity determined in one experiment performed in triplicate. These data are representative of three independent experiments. Statistical differences (P values) are indicated. (D) Upper panel: representative microscopic photos of the average cell density after 300 min of infection (for visualization purposes, magnification was at 100X). Bottom panel: the percentage of viable cells, assessed by the neutral red assay, was determined as described in Figure 2A. Data are the mean + SEM and are representative of three independent experiments. Statistical differences (P values) are indicated.