IL-13 enhances HCMV gene expression in infected macrophages. Day 7 alveolar macrophages, cultured at a density of 1 × 106 cells/well, were pretreated for 2 days with 50 ng/mL IL-13, unless indicated otherwise, and then exposed to HCMV Davis (MOI of 1). The virus was removed after 4 hours and the cells were maintained as follows: Mock: No IL-13. Cells fixed at day 14; 7/0: IL-13 for 7 days after HCMV infection. Cells fixed at day 7; 7/7: IL-13 for 7 days after HCMV infection. Cultures maintained for an additional 7 days without IL-13 and fixed on day 14; 10/4: IL-13 for 10 days after HCMV infection. Cultures maintained for an additional 4 days without IL-13 and fixed on day 14. 14/0: IL-13 for 14 days after HCMV infection, until the cells were fixed on day 14. All cells were fixed in methanol and probed with anti-CMV IE antibody. HCMV (+) cells were quantified under a light microscope 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.
