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Updated: Aug 8, 2026
Generation of Human CD40-activated B cells
Published on: October 17, 2009
Functional interaction between interleukin-9/P40 and interleukin-4 in the induction of IgE production by normal human
B Dugas1, J Van Snick, J C Renauld
1Institut Henri Beaufour, Les Ulis, France.
Insights
Interleukin-9/P40 (IL-9/P40) enhances immunoglobulin E (IgE) production by B lymphocytes when combined with Interleukin-4 (IL-4). IL-9/P40 also potentiates IgG and IgM production, suggesting a regulatory role in B cell responses.
Area of Science:
- Immunology
- Cell Biology
Background:
- Interleukin-4 (IL-4) is known to stimulate IgE production in B lymphocytes.
- The role of Interleukin-9/P40 (IL-9/P40) in B cell immunoglobulin production requires further elucidation.
Purpose of the Study:
- To investigate the effect of IL-9/P40 on IgE production by human B lymphocytes.
- To determine if IL-9/P40 modulates other immunoglobulin classes (IgG, IgM) and interacts with IL-4.
Main Methods:
- Human peripheral blood B lymphocytes were cultured with varying concentrations of IL-4 and/or IL-9/P40.
- Immunoglobulin production (IgE, IgG, IgM) was measured.
- B lymphocytes were preactivated with Staphylococcus aureus Cowan strain I to assess cytokine effects on activated cells.
Main Results:
- IL-4 alone induced significant IgE production in a dose-dependent manner.
- IL-9/P40 alone did not induce IgE production but enhanced IL-4-induced IgE production.
- IL-9/P40 potentiated IL-4-induced IgG and IgM production in both unactivated and activated B lymphocytes.
Conclusions:
- IL-9/P40 plays a direct role in regulating immunoglobulin production by B lymphocytes.
- IL-9/P40 acts synergistically with IL-4 to enhance IgE production.
- IL-9/P40 also influences IgG and IgM production, indicating a broader regulatory function in B cell responses.
Abstract:
Interleukin-4 (IL-4) has been shown to induce a high rate of IgE production by normal B lymphocytes from peripheral blood without preactivation of these cells. In the present study, significant IgE production was observed at the concentration of 30 U/mL IL-4 (0.5 ng IgE/mL), and a plateau value was reached at 300 U/mL (1.2 ng IgE/mL). In these experiments, recombinant human (rh) and murine (rm) interleukin-9/P40 (IL-9/P40) were unable to induce such an IgE production by human B lymphocytes. However, in the presence of a suboptimal dose of IL-4 (100 U/mL), both rh and rm IL-9/P40 enhanced the IgE production in a dose-dependent manner (from 3 to 1000 U/mL). Under these experimental conditions, the slight but significant (p < 0.01, Student's t test) production of IgG (50 ng/mL) was also potentiated when the cell cultures were performed in the presence of 300 U/mL of IL-9/P40. The IL-4-induced IgG and IgM production by purified B lymphocytes preactivated with Staphylococcus aureus Cowan strain I was also potentiated in the presence of 300 U/mL of rh IL-9/P40, indicating a direct effect of this cytokine on this cell type. In contrast, IgE production by Staphylococcus aureus Cowan strain I-activated B lymphocytes was never observed. Taken together these data suggested a direct role for IL-9/P40 in the regulation of immunoglobulin production by B lymphocytes.
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