The ability of IL-21 to induce IgE secretion by CD40L-activated human B cells is independent of endogenous IL-4 but partially dependent on endogenous IL-6
| Culture . | IgE secretion (ng/mL) . | |||
|---|---|---|---|---|
| No mAb . | Control mAb . | Anti-IL-4 mAb . | Anti-IL-6 mAb . | |
| Experiment 1 | ||||
| CD40L | <0.1 | ND | ND | — |
| CD40L IL-4 | 7.6 ± 0.32 | ND | <0.1 | — |
| CD40L IL-21 | 3.9 ± 0.9 | 3.02 ± 0.24 | 4.28 ± 0.9 | — |
| CD40L IL-4/IL-21 | 41.8 ± 2.5 | 34.8 ± 4.7 | 4.1 ± 0.47 | — |
| Experiment 2 | ||||
| CD40L | <0.1 | ND | ND | — |
| CD40L IL-4 | 1.90 ± 0.3 | ND | <0.1 | — |
| CD40L IL-21 | 4.9 ± 0.9 | 3.7 ± 0.46 | 4.2 ± 1.1 | — |
| CD40L IL-4/IL-21 | 73.1 ± 13.0 | 84.0 ± 3.8 | 7.6 ± 2.3 | — |
| Experiment 3 | ||||
| CD40L | <0.1 | ND | — | <0.1 |
| CD40L IL-4 | <0.1 | <0.1 | — | <0.1 |
| CD40L IL-21 | <0.1 | <0.1 | — | <0.1 |
| CD40L IL-4/IL-21 | 48.6 ± 10 | 40.0 ± 8.0 | — | 24.0 ± 3.7 |
| Experiment 4 | ||||
| CD40L | <0.1 | ND | — | <0.1 |
| CD40L IL-4 | <0.1 | ND | — | <0.1 |
| CD40L IL-21 | 6.4 ± 2.2 | ND | — | 4.4 ± 1.8 |
| CD40L IL-4/IL-21 | 170 ± 2.0 | ND | — | 80.6 ± 18.2 |
| Culture . | IgE secretion (ng/mL) . | |||
|---|---|---|---|---|
| No mAb . | Control mAb . | Anti-IL-4 mAb . | Anti-IL-6 mAb . | |
| Experiment 1 | ||||
| CD40L | <0.1 | ND | ND | — |
| CD40L IL-4 | 7.6 ± 0.32 | ND | <0.1 | — |
| CD40L IL-21 | 3.9 ± 0.9 | 3.02 ± 0.24 | 4.28 ± 0.9 | — |
| CD40L IL-4/IL-21 | 41.8 ± 2.5 | 34.8 ± 4.7 | 4.1 ± 0.47 | — |
| Experiment 2 | ||||
| CD40L | <0.1 | ND | ND | — |
| CD40L IL-4 | 1.90 ± 0.3 | ND | <0.1 | — |
| CD40L IL-21 | 4.9 ± 0.9 | 3.7 ± 0.46 | 4.2 ± 1.1 | — |
| CD40L IL-4/IL-21 | 73.1 ± 13.0 | 84.0 ± 3.8 | 7.6 ± 2.3 | — |
| Experiment 3 | ||||
| CD40L | <0.1 | ND | — | <0.1 |
| CD40L IL-4 | <0.1 | <0.1 | — | <0.1 |
| CD40L IL-21 | <0.1 | <0.1 | — | <0.1 |
| CD40L IL-4/IL-21 | 48.6 ± 10 | 40.0 ± 8.0 | — | 24.0 ± 3.7 |
| Experiment 4 | ||||
| CD40L | <0.1 | ND | — | <0.1 |
| CD40L IL-4 | <0.1 | ND | — | <0.1 |
| CD40L IL-21 | 6.4 ± 2.2 | ND | — | 4.4 ± 1.8 |
| CD40L IL-4/IL-21 | 170 ± 2.0 | ND | — | 80.6 ± 18.2 |
B cells purified from different CB samples were cultured (∼10-20 × 103 cells per 200 μL per well) with CD40L alone or together with IL-4, IL-21, or both IL-4 and IL-21 in the absence or presence of a control mAb, neutralizing anti–IL-4 mAb (experiments 1, 2) or neutralizing anti-IL-6 mAb (experiments 3, 4). After 8 to 10 days, supernatants were harvested and the amount of secreted IgE determined by ELISA. These results represent the means plus or minus the SEM of replicate cultures.
ND indicates not done; and —, not applicable.