FIG. 7.

Barrier properties in pmBECs after MAV-1 infection. (A) pmBECs were grown to confluence on 0.4-μm-pore-size transwell plates with 20% conditioned astrocyte medium added to both the upper and lower chambers to promote tight junction formation. Cells were infected with wt MAV-1 or pmE314 at an MOI of 5 or mock infected. Resistance was measured at 24-hour intervals. (B and C) Mitochondrial metabolic activity as a surrogate for cell viability was measured by MTT assay at 2 days postinfection (B) in a replicate experiment and at 3 days postinfection (C) on the same cells as in panel A. TEER results are representative of four experiments for panel A, three experiments for panel B, and two experiments for panel C. OD 570, optical density at 570 nm. (D and E) TEER was measured in cells infected with wt MAV-1 or pmE314. Recombinant CCL2 was added to mock-infected cells after 2 days (D) or 3 days (E), and 1 h later CCL2-neutralizing antibody (CCL2 Ab) or naïve rabbit serum (control) was added to all cells as indicated. Note that after treatment the x axis is on a different scale. Error bars indicate means and standard deviations when triplicate samples were available. All other samples were analyzed in duplicate in multiple experiments.