FIG. 2.

Inhibition of progeny virus production in polarized pIgR⁺MDCK cells cocultured with hybridoma cells in Transwell-Col filter chambers. Filter-grown confluent MDCK cell monolayers laying on top of hybridoma cell-containing collagen layers were infected with 4 × 10³ PFU of RRV from the apical side after 24 h of dexamethasone stimulation. After virus binding at 37°C for 90 min, the apical medium was replaced and cells were further incubated at 37°C for 18 h. Filters were removed and extensively washed to eliminate extracellular antibodies. Cells were disrupted by freeze-thawing and extraction with 1,1,2-trichloro-trifluoro-ethane to release intracellular virions. Infectious progeny virus titers were determined by infection of MA104 cell monolayers and immunoperoxidase staining as described in detail in Materials and Methods. Columns indicate the percentages of recovered infectious virus compared to control MDCK cell monolayers infected in the absence of hybridoma cells. Data represent the averages of three independent experiments (bars indicate ranges). 1E4, 2A10, 2B12, and 4B6 were IgA MAbs to VP4; 1D4, 2C5, and 2F8 were IgA MAbs to VP6; 1A9 and 7A12 were IgG MAbs to VP4; and 3C10 was an IgA MAb to Sabin 1 poliovirus.