S. suis and TNFα alter the morphology of the tight junction protein occludin and induce actin stress fiber formation after the transmigration of PMNs across PCPECs. (A-P) En face Apotome microscopy of control (A-D), S. suis (strain 10: E-H, strain 10 Δcps: I-L) and TNFα- (M-P) stimulated PCPEC monolayers stained for occludin (red), actin (phalloidin, green) and nuclei (DAPI, blue) after PMN (yellow) transmigration. Top and side of each panel is a cross section through the z-plane of multiple optical slices. This figure is a representative example of three independent experiments that all gave similar results. Scale bar, 10 μm.