IL-13 enhances lacZ production by a recombinant HCMV virus. Alveolar macrophages, cultured at a density of 1 × 106 cells/ well for 7 days, were pretreated with different doses of IL-13 for 2 days before infection with HCMV. Cultures were then exposed to CMV RC256 (MOI of 1) for 4 hours, washed 3× with PBS, and refed with growth medium containing the noted concentrations of IL-13. Cells were fixed at day-5 postinfection and assayed by X-gal staining for β-gal activity. The numbers of cells expressing β-gal were quantitated by light microscopy at 200× magnification. Data are derived from 3 wells from 3 different experiments. Statistically significant differences from the control were determined by employing the Student's t-test. * = P < .05; ** = P < .01; *** = P < .001.
