Figure 5. IgA and IgG isotype‐dependent functional differences in the effect of monoclonal antibodies on MTB infection of human lung epithelial cells.

Relative bacterial counts (CFU) compared with the medium control (100%; dashed lines) in human lung epithelial A549 cells 1 h after infection with MTB, preincubated with recombinant MTB‐reactive IgA1, IgA2, or IgG1 antibodies and nonreactive isotype control as indicated.

1. Representative results for individual MTB‐reactive plasmablast antibodies. Mean and SEM are indicated.
2. Direct comparison of all tested MTB‐reactive IgA (n = 12) and IgG (n = 26) antibodies.
3. Representative results for individual HBHA‐reactive memory B‐cell antibodies from TB patients and HCW.
4. Same as in (B) but with HBHA‐reactive antibodies as shown in (C). Direct comparison of all tested HBHA‐reactive IgA (n = 6) and IgG (n = 7) antibodies.
5. Direct comparison of the indicated MTB‐reactive antibodies expressed as IgA and IgG. Mean and SEM are indicated.

Data information: Data are representative of at least two independent experiments with three technical replicates each. (B, D) P‐values were determined using Wilcoxon–Mann–Whitney test, ***P < 0.001; ****P < 0.0001. (E) P‐values were determined using nonparametric t‐test, *P < 0.1; **P < 0.01, ns: P > 0.5.