FIG. 6.

Effect of tunicamycin treatment on the expression of the protective 190/4 epitope in dog cell transfectants. Dog cells expressing the flag receptor or control DR2 cells transfected with the vector alone were treated with 1 μg of tunicamycin per ml for 0, 1, 2, and 3 days. After treatment, expression of the 190/4 (flag/190-4 and DR2/190-4) and M2 (flag/M2 and DR2/M2) epitopes was determined by cell surface ELISA with a saturating concentration of 190/4 and M2 MAbs (200 μg/ml), peroxidase-labeled goat anti-mouse Ab, and TMB substrate. Absorbance was read at 450 nm. Data are means of values from duplicate wells ± standard errors of the means.