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Updated: Aug 9, 2026
Generation of Human CD40-activated B cells
Published on: October 17, 2009
CD40 ligand is functionally expressed on human eosinophils
J F Gauchat1, S Henchoz, D Fattah
1Glaxo Institute for Molecular Biology, Plan les Ouates/Geneva, Switzerland.
Insights
CD40 ligand (CD40L) is expressed by eosinophils, which can promote B cell proliferation. This finding suggests a role for eosinophils and CD40L in inflammatory conditions.
Area of Science:
- Immunology
- Cell Biology
Background:
- CD40 ligand (CD40L) is a molecule expressed on immune cells like T cells, mast cells, and basophils.
- CD40L plays a key role in B cell proliferation, immunoglobulin class switching, and monocyte/T cell activation.
Purpose of the Study:
- To investigate the expression of CD40L by eosinophils.
- To determine the functional role of eosinophil-derived CD40L in B cell activation.
Main Methods:
- Analysis of CD40L expression on eosinophils from a hypereosinophilic patient and an eosinophilic cell line (EOL-3).
- In vitro experiments assessing the ability of activated normal blood eosinophils to induce B cell proliferation in the presence of IL-4.
Main Results:
- CD40L was constitutively expressed by eosinophils from a hypereosinophilic patient.
- Activated eosinophils (EOL-3 cell line and normal blood eosinophils) also expressed CD40L.
- Eosinophils, in conjunction with IL-4, induced CD40L-dependent B cell proliferation in vitro.
Conclusions:
- Eosinophils can express CD40L, both constitutively in disease and upon activation.
- Eosinophil-derived CD40L contributes to B cell proliferation, suggesting a role in inflammatory processes involving eosinophils.
Abstract:
CD40 ligand (CD40L), a surface molecule which can be expressed by T cells, mast cells and basophils, has been shown to be involved in the control of B cell proliferation, immunoglobulin class switching as well as in the activation of monocytes and T cells. We demonstrate that CD40L can also be expressed constitutively by eosinophils from an hypereosinophilic patient or, upon activation, by the eosinophilic cell line EOL-3 and normal blood eosinophils. Eosinophils were able to induce, in conjunction with IL-4, CD40L-dependent B cell proliferation in vitro. These results suggest that CD40L could play a role in the inflammatory processes during which eosinophil infiltration and activation are observed.
