Figure 2.

The 5ʹ-nucleotidase activity of Ssads contributes to S. suis translocation across the monolayers derived from human brain microvascular endothelial cells. After HCMEC/D3 cells formed confluent and tight monolayers on transwell filters, S. suis strains were added to the apical surfaces of monolayers at an MOI of 100. (a) In the presence or absence of APCP (500 µM), a known 5ʹ-nucleotidase inhibitor, S. suis cells in the lateral chamber after 1 h were quantitated. (b) The effect of the adenosine analog NECA (1 µM) on bacterial translocation across HCMEC/D3 monolayers at 1 h post-treatment was determined. (c–d) The permeability coefficient to Lucifer yellow (LY) of HCMEC/D3 monolayers was measured 1 h post-infection with S. suis in the presence or absence of APCP (500 µM; c) or NECA (1 µM; d). Data are expressed as means and SEM. *P < 0.05, **P < 0.01, ***P < 0.001, 2-tailed Student’s t test. (e–h) The TEER in HCMEC/D3 monolayers infected with S. suis in the presence or absence of APCP (500 µM) (e–g) or NECA (1 µM) (h) was measured. D-mannitol (10 µM) was used as a positive control as it disrupts cell-cell junctions. Data are expressed as means and SEM. ^###P < 0.001 analyzed by two-way ANOVA, and the following significant differences (*P < 0.05, ***P < 0.001 by Bonferroni multiple comparison test) between the corresponding groups at the indicated time points are displayed.