Fig. 2: In vitro characterization of FNI9, FNI17 and FNI19 mAbs.
From: A pan-influenza antibody inhibiting neuraminidase via receptor mimicry
a, FNI9, FNI17, FNI19 and 1G01 mAbs neutralization half-maximal inhibitory concentration (IC50) values against a panel of seasonal IAVs (H1N1 is blue; H3N2 pre-2015 is in red and H3N2 post-2015 is in orange) and IBVs (B/Victoria/2/87-like viruses are in light green, B/Yamagata/16/88-like viruses are in dark green and ancestral is in olive). Full viral strain designations and IC50 values are listed in Supplementary Table 3. Geometric mean of n = 2 independent experiments for each strain is shown. The black solid line indicates the median IC50 for each mAb. Symbols on the dotted line represent strains against which the mAbs did not reach IC50 at the concentrations tested in the assay (see Supplementary Table 3). b, Binding affinity (Kd) of anti-NA Fab fragments to N2 NA antigens not bearing (−) or bearing (+) glycan at position 245 as measured by SPR. Full details of the antigens tested and Kd values are reported in Supplementary Table 4. Results represent an average of at least two technical replicates from one independent experiment. Dotted lines represent the limits of detection. c, Inhibition of enzymatic activity, as measured by ELLA, exerted by anti-NA mAbs on NA antigens not bearing (−) or bearing (+) N245 glycan. Full details of the antigens used are reported in Supplementary Table 4. d, Inhibition of enzymatic activity, as measured by ELLA, exerted by anti-NA mAbs against NA-only based pseudoparticles bearing N3, N6, N7, N8 or N9 representative of zoonotic isolates. Dotted lines in c and d represent the minimum and maximum percentage of inhibition. Results represent two technical replicates from one independent experiment out of two. Error bars indicate s.d. of technical duplicates. e, In vitro neutralization matrixes (top panels) and synergy plots (bottom panels) reporting combination activity of anti-HA stem-directed MEDI8852 and anti-NA FNI9 mAbs to H1N1 A/Puerto Rico/8/34 (left) and H3N2 A/Tasmania/503/2020 (right) viruses. Neutralization matrixes were performed in technical triplicates with one of two independent experiments shown.
