Group B Streptococcus Hijacks the Host Plasminogen System to Promote Brain Endothelial Cell Invasion (original) (raw)

< Back to Article

Figure 2

Plasmin(ogen)-coated GBS induces hBMECs detachment and injury.

GBS cells were preincubated without (untreated GBS) or with (PLG-treated GBS) plasminogen plus tPA, or pre-treated with εACA prior to plasminogen plus tPA incubation (εACA-treated GBS). HBMECs monolayers were infected with 106 CFU (MOI of 10) of untreated GBS, PLG-treated GBS or εACA-treated GBS, for 120 min at 37°C; uninfected cells were used as negative controls. (A) Upper panel: representative microscopic photos of the average cell density were taken at ×100 magnification for visualization purposes. Lower left panel: percentage of viable cells, determined by the neutral red assay, expressed relative to the number of viable cells observed in uninfected control. Lower right panel: Cell viability determined by measuring the LDH release. Data represents mean the values normalized to the mean 100%-death control + SEM from an experiment performed in triplicate that is representative of three independent experiments. (B) Plasmin-like activity in bacterial cell surface. The plasmin activity in GBS surface was assessed following incubation with its specific chromogenic substrate S-2251 and determination of the absorbance at 405 nm. Data represents mean + SEM from an experiment performed in triplicate that is representative of three independent experiments.

Figure 2

doi: https://doi.org/10.1371/journal.pone.0063244.g002