Time dependence of PIC-induced permeability. PIC induced permeability was quantified using the TEER assay. HMEC-1 cells were seeded onto collagen-coated membrane inserts and infected with PIC at MOI's of 0.1, 1, 3 or mock-infected. Each experimental condition was performed in triplicate. Results are expressed at % increase in permeability over basal permeability levels.