Figure 2.

Time course of IFN-γ-induced internalization of occludin and development of subapical F-actin-coated vacuoles. Confluent T84 monolayers were incubated with 100 U/ml IFN-γ for 12-48 h. Internalization of occludin (arrowheads) into F-actin-coated vacuoles (arrows) was determined by fluorescence labeling and confocal microscopy. After 24 h of IFN-γ incubation, organization of occludin and F-actin was analogous to that observed in polarized control epithelial cells. The first evidence of occludin internalization into F-actin-coated vacuoles was observed after 38 h of IFN-γ incubation. This effect was augmented at 48 h of IFN-γ incubation. Scale bar, 10 μm.