Epitope Dampening Monotypic Measles Virus Hemagglutinin Glycoprotein Results in Resistance to Cocktail of Monoclonal Antibodies
Figure 5
MV-δE4 evades neutralization by a cocktail of mAbs targeting E1–4 simultaneously.
A) Cartoon structure of the MV-δE4 H cuboidal ectodomain (Top View) illustrates mutations as spheres. Orange spheres are Asparagine (N) residues available for N-linked glycosylation in PNGS 282NDL→NDS and 535EHA→NAT. Orange circles represent glycan shields. Yellow spheres highlight cl48 selected escape mutations E395K. Red spheres highlight BH38 (red) selected mutation Y310C and also E471K (which was present in ¼ BH38 resistant clones sequenced). Box highlights E1–4, delineated by the location of mutations escaping mAbs present in each box. Underlined are mAbs used in the cocktail mix in C) and D). B) MV-eGFP and MV-δE4 were incubated in the absence (black solid bar) and presence (hatched bars) of individual mAbs prior to infection of Vero cells. Infection was scored 48 hours latter by counting the number of eGFP expressing syncytia per well. BH97 was used as a positive control for MV-δE4 neutralization. C) MV-eGFP and MV-δE4 were then challenged with media alone (no mAb), a cocktail of mAbs targeting all four epitopes simultaneously: BH15 (E1), 16DE6 (E2), cl48, (E3) and BH141 (E4) with or without BH97 (control). D) Infection was visualized 48 hrs post infection by fluorescence microscopy at 4× magnification.