Neutralization sensitivity of WNV E T198F RVPs to mAbs.

<p><b>(A)</b> Top (left panel) and side (right panel) views of the crystal structure of the WNV E protein monomer (PDB 2HG0) are shown, with domains I, II, and III (DI, DII, and DIII), and the fusion loop of DII (DII-FL) indicated below the structure. The side view was obtained by rotating the structure in the left panel 90 degrees towards the page. On the structure, amino acid residues important for recognition by mAb E60 in the DII-FL [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1006178#ppat.1006178.ref058" target="_blank">58</a>] and by mAb E16 [<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1006178#ppat.1006178.ref059" target="_blank">59</a>] in DIII are indicated by the green and purple spheres, respectively. Gray spheres indicate residues within DI-DII hinge that were mutated for epitope mapping studies. The blue spheres and black arrow indicate the location of threonine at E protein residue 198 described in this study <b>(B)</b> Representative dose-response neutralization curves for WT and T198F WNV RVPs tested concurrently against mAbs E60 and <b>(C)</b> E16. The y- and x-axes indicate percent infectivity and mAb concentration, respectively. Infectivity was normalized to levels observed in the absence of antibody. Error bars indicate the range of infectivity from duplicate wells. We performed paired t-tests to compare the EC50 values of <b>(D)</b> E60 and <b>(E)</b> E16 against WT and T198F RVPs obtained from six independent experiments performed in duplicate. Error bars indicate the standard error of the mean (SEM).