Extended Data Fig. 3: Characterization of Fc domain variants with differential FcγR binding to assess in vivo ADE of dengue disease.

(a) Affinity of human IgG1 Fc domain variants for the various classes of human FcγRs and type II mouse FcRs. Numbers indicate the fold change in affinity compared with wild-type human IgG1. n.d.b.: no detectable binding. (b-d) Ifnar1^−/−/FcγR humanized mice were administered i.v. with 20 μg or 200 μg of the ALIE variant of anti-DENV 2D22 mAb 8h before DENV2 challenge. Weight loss (b), survival (c), and platelet counts (d) were compared between the two doses by two-way ANOVA (Bonferroni post hoc analysis adjusted for multiple comparisons), log-rank (Mantel-Cox) test and two-tailed t-test, respectively. n = 6 mice per group in two independent experiments. Data are presented as mean ± s.e.m. *P<0.03; ***P<0.0008; ****P<0.0001. (e) Serum was obtained from DENV-infected mice (pre-treated with the different anti-DENV Fc variants) on day 3 post-infection and analyzed by ELISA to quantify antibody levels. IgG levels of the various Fc variants were compared to WT human IgG1 by two-way ANOVA (Bonferroni post hoc analysis adjusted for multiple comparisons). n = 7 (V11, ALIE, GAALIE), n = 8 (GA, afucosylated), n = 9 (GRLR), n = 11 (WT) mice per group from at least two independent experiments. Data are presented as mean ± s.e.m. (f) Ifnar1^−/−/FcγR humanized mice were administered with 20 μg of anti-DENV mAb Fc-variants (GRLR or GAALIE) and platelet counts (mean ± s.e.m.) were measured 3 days post treatment and compared to mice that were treated with WT mAb by one-way ANOVA (Bonferroni post hoc analysis adjusted for multiple comparisons). n = 3 (WT, GRLR), n = 4 (GAALIE) mice per group from one independent experiment. NS, not significant.