Fig. 2
Expression of human adenovirus-encoded factor H binding protein N-terminal signal sequence variants from HeLa cells. A HeLa cells (1 × 106 per sample) were infected overnight with 5 × 108 infectious units of one of a series of human adenovirus serotype 5 (AdHu5) constructs encoding an N-terminal sequence variant of the factor H binding protein (fHbp) and expression was quantified by flow cytometry after surface and intracellular staining of harvested cells with an anti-fHbp antibody (JAR5) and a fluorescently-tagged detection antibody. Cells were tested for intracellular expression by stimulation with brefeldin A to stop protein transport within the cells and harvested at B three-hour and C five-hour timepoints post-infection to measure early expression levels by intracellular staining. The y-axis corresponds to the percentage of total fluorescent (fHbp-expressing) HeLa cells after overnight infection. The amino acid composition of the N-terminal sequence impacts upon the expression of the transgene-encoded antigen within the first 24 h of infection. Statistical comparisons were made using a Mann–Whitney U-test. *p < 0.05; **p < 0.01; ***p < 0.001