FIG. 3.

Resistance of clonal transformed C6/36 cell lines to DEN-2 challenge. Clonal cell lines were selected by resistance to hygromycin and challenged with DEN-2 infection at an MOI of 0.01. The height of bars shows the percentage of cells containing DEN-2 E antigen by IFA 7 days postchallenge. (A) Bars a to j (shaded), cell lines transformed with pIE1-null (H cell lines); bars k to z" (open), cells transformed with pIE1D2prMir (FB cell lines). (B) Bar a, H cell line; bars b to l (stippled), cell lines transformed with pIE1D2prM290s (S cell lines); bars m to z‴ (striped), cells transformed with pIE1D2prMas (As cell lines). Cell lines with <5% E-antigen-containing cells (arrows) were considered DEN-2 resistant.