Fig. 3. MBCs and serum antibodies commonly target the anchor epitope.
a, Proportion of all cH5/1+ B cells with repertoire features of anchor-binding mAbs, VH1-69/κ (CS epitope) or with other repertoire features. The number in the centre of the pie graph is the number of B cells analysed. b, Proportion of B cells with anchor-binding mAb features or that use VH1-69/κ-chain by participant (n = 20 donors). Lines connect the same participant. Data were analysed using a two-tailed paired non-parametric Wilcoxon matched-pairs signed rank test. c, Electron microscopy polyclonal epitope mapping (EMPEM) summary of polyclonal antibodies (pAbs) binding to A/Michigan/45/2015 HA in the serum of participants 236 and 241 collected at day 7 and day 14 following 2014 quadrivalent inactivated influenza vaccine. Fabs shown as graphics with dotted lines represent predicted placements due to limited particle representation. 2D class averages were imaged at ×62,000 normal magnification d, Overlap of 241 IgA 2F04 Fab and pAb binding the anchor epitope from participant 241. See also Extended Data Fig. 5.