Table 2. Anti-viral functions of IgG and IgA antibodies derived from clones B12 and Fab-deficient (ΔFab) IgA antibodies.
| B12 | ΔFab | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| H1N1 | H3N2 | H1N1 | H3N2 | ||||||||
| Cal7 | NC20 | PR8 | Vic210 | NY55 | Cal7 | NC20 | PR8 | Vic210 | NY55 | ||
| NT activity [μg/mL] Geometric mean (Geometric SD) | G | >500 | >500 | >500 | >500 | >500 | n.t. | n.t. | n.t. | n.t. | n.t. |
| A1M | >500 | >500 | >500 | 27.8 (1.69) | 158 (1.76) | n.t. | n.t. | n.t. | >500 | n.t. | |
| A1P | >500 | >500 | >500 | 24.8 (1.43) | 99.2 (1.43) | n.t. | n.t. | n.t. | >500 | n.t. | |
| A2M | >500 | 630 (1.43) | >500 | 7.81 (1.55) | 35.1 (1.69) | n.t. | n.t. | n.t. | >500 | n.t. | |
| A2P | >500 | 500 (1) | >500 | 22.1 (1.79) * | 99.2 (2.32) | n.t. | n.t. | n.t. | >500 | n.t. | |
| HI activity [μg/mL] Geometric mean (Geometric SD) | G | >500 | >500 | >500 | >500 | >500 | n.t. | n.t. | n.t. | n.t. | n.t. |
| A1M | >500 | 500 (1) | >500 | 125 (1) | 158 (1.43) | n.t. | >500 | n.t. | 794 (1.43) | n.t. | |
| A1P | >500 | 500 (1) | >500 | 125 (1) | 177 (1.46) | n.t. | >500 | n.t. | >500 | n.t. | |
| A2M | >500 | 250 (1) | >500 | 39.4 (1.43) | 62.5 (1) | n.t. | >500 | n.t. | 500 (1) | n.t. | |
| A2P | >500 | 500 (1) ** | >500 | 125 (1) ** | 125 (1) ** | n.t. | >500 | n.t. | >500 | n.t. | |
| NI activity [ng/mL] (EC50) | G | ND | 9.57E+07 | ND | 1.62E+05 | ND | n.t. | ND | n.t. | ND | n.t. |
| A1M | ND | 1.63E+05 | ND | 5.03E+03 | 1.54E+03 | n.t. | ND | n.t. | ND | n.t. | |
| A1P | ND | 5.24E+04 | ND | 5.05E+03 | 1.64E+03 | n.t. | ND | n.t. | ND | n.t. | |
| A2M | ND | 8.14E+03 | ND | 2.70E+03 | 866 | n.t. | ND | n.t. | ND | n.t. | |
| A2P | ND | 8.48E+04 | ND | 6.50E+03 *** | ND ** | n.t. | ND | n.t. | ND | n.t. | |
| Binding activity [ng/mL] (EC50) | A1M | 3.80E+04 | 2.95E+04 | 1.68E+04 | 1.08E+05 | 6.28E+04 | 1.34E+04 | 2.00E+04 | 1.69E+04 | 3.65E+05 | 2.85E+05 |
| A1P | 4.89E+11 **** | 6.28E+10 **** | 3.11E+05 *** | 4.14E+05 *** | 6.01E+05 ** | ND **** | 1.44E+10 **** | 1.32E+08 | 8.92E+04 | 6.57E+06 | |
| A2M | 2.73E+04 | 3.08E+04 | 4.08E+04 | 2.38E+04 | 2.92E+04 | 984 | 1.12E+03 | 724 | 778 | 823 | |
| A2P | 5.28E+08 **** | 3.18E+06 **** | 1.18E+07 **** | 1.45E+06 **** | 8.44E+05 **** | 2.19E+05 **** | 5.98E+05 **** | 6.72E+05 **** | 2.51E+05 **** | 1.07E+05 **** | |
NT activity, virus-neutralizing activity. Minimum virus-neutralizing concentrations are presented as the geometric mean (geometric SD) of six technical replicates. HI activity, hemagglutination inhibition activity. Minimum HI concentrations are presented as the geometric mean (geometric SD) of six technical replicates. NI activity, neuraminidase inhibition activity. EC50 values were calculated from three technical replicates. Binding activity, antibody binding activity to recombinant HA measured by ELISA. EC50 values were calculated from three technical replicates. G, IgG1; A1M, IgA1 monomer; A1P, IgA1 polymer; A2M, IgA2m2 monomer; A2P, IgA2m2 polymer; Cal7, A/California/7/2009 (H1N1); NC20, A/New Caledonia/20/1999 (H1N1); PR8, A/Puerto Rico/8/1934 (H1N1); Vic210, A/Victoria/210/2009 (H3N2); NY55, A/New York/55/2004 (H3N2, NY55); ND, not detected; n.t., not tested.
*p < 0.05
**p < 0.01
***p < 0.001
****p < 0.0001 (Mann–Whitney test comparing the NT and HI activity of monomers with polymers; two-way ANOVA comparing NI and binding activity curves of monomers with those of polymers).