Hemagglutinin inhibition and neutralizing activities of F045-092 on IgG and IgA, with or without polymerization.

(A–H) HI activity of F045-092 IgG1, monomeric (Mo) IgA1, dimeric (Di) SIgA1, tetrameric (Te) SIgA1, monomeric (Mo) IgA2m2, tetrameric (Te) SIgA2m2 against Syd05 (A), NY55 (B), NY39 (C), Vic210 (D), Vic361 (E), NC20 (F), JP305 (G), or Ind05 (H) viruses. HI activity is shown on scatter plots as the geometric mean (with 95% confidence intervals) of the reciprocal of the lowest concentration (μg/ml) of antibody that inhibited hemagglutination of the virus (n = 4 for H3 viruses, n = 6 for JP305 and Ind05 viruses, and n = 9 for NC20 virus). (I–P) NT activity of F045-092 IgG1, monomeric (Mo) IgA1, dimeric (Di) SIgA1, tetrameric (Te) SIgA1, monomeric (Mo) IgA2m2, and tetrameric (Te) SIgA2m2 against Syd05 (I), NY55 (J), NY39 (K), Vic210 (L), Vic361 (M), NC20 (N), JP305 (O), or Ind05 (P) viruses. NT activity is expressed on scatter plots as the geometric mean (with 95% confidence intervals) of the reciprocal of the lowest concentration (μg/ml) of antibody that neutralized the virus (n = 4 for H3 viruses, n = 6 for JP305 and Ind05 viruses, and n = 9 for NC20 virus). The dotted line in the graph represents the detection limit (DL) of each experiment. Half of the detection limit value was applied to samples with titers below the detection limit for statistical analyses. *pppp<0.0001 (compared with IgG; Kruskal-Wallis test followed by Dunn’s multiple comparison test).