Two Escape Mechanisms of Influenza A Virus to a Broadly Neutralizing Stalk-Binding Antibody
Fig 5
39.39 blocks the low-pH induced conformational change of the WT HA but not the mutant HAs.
293T cells expressing the Q387K, D391Y, F175Y/D391G or WT A/Perth/16/2009 HA were collected before (Stage 1) or after (Stage 2) trypsin treatment to activate HA0. A fraction of trypsin-treated cells were incubated with 39.29 and then subjected to a pH4.8 buffer to induce HA conformational change (Stage 3). Cells at each stage were tested for 39.29 binding by flow cytometry. The mean fluorescence intensities were normalized to the WT and the percentages of binding are shown as histograms. The possible HA conformations at each stage are depicted above the binding data. HA1 is in blue and HA2 is in red. Mock, mock transfected cells.