Combined effect of DENV1 mutations E126K/E157K on the neutralization potency of DENV1 immune serum.

<p>(<b>A</b>) The location of residues E126 and E157 are highlighted on the E protein crystal structure as cyan and green spheres, respectively. E protein domains are colored as in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003761#ppat-1003761-g001" target="_blank"><b>Figure 1</b></a>. (<b>B</b>) Infectious titer of DENV1 E126K/E157K RVPs harvested at four time points post-transfection was determined in parallel studies with WT DENV1 using Raji-DCSIGNR cells; error bars represent the standard error of the mean of 2–4 independent experiments. (<b>C and D</b>) DENV1 E126K/E157K RVPs were tested for sensitivity to neutralization by the DENV1 immune serum. (<b>C</b>) Representative dose-response curves for the single and double mutants are shown; error bars represent the standard error of duplicate infections. (<b>D</b>) The neutralization sensitivity is summarized as the fold-increase in NT50 from WT DENV1 for the single mutants E126K and E157K (n = 10), the E126K/E157K double mutant (n = 11), and DENV2 (n = 11); error bars represent the standard error of the mean. ***p<0.0001 for a comparison of the Log NT50 values to WT DENV1 by an ANOVA followed by Tukey's multiple comparisons test.