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Updated: Aug 8, 2026
Generation of Human CD40-activated B cells
Published on: October 17, 2009
Recombinant human CD40 ligand stimulates B cell proliferation and immunoglobulin E secretion
M K Spriggs1, R J Armitage, L Strockbine
1Department of Molecular Biology, Immunex Research and Development Corporation, Seattle, Washington 98101.
Insights
Researchers identified the human CD40 ligand (hCD40-L), crucial for B cell proliferation and differentiation. This T cell-expressed molecule activates B cells, inducing immunoglobulin secretion, highlighting its role in immune responses.
Area of Science:
- Immunology
- Molecular Biology
Background:
- CD40 signaling is vital for B lymphocyte proliferation and differentiation.
- Previous identification of murine CD40 ligand (mCD40-L) with in vitro biological activity.
Purpose of the Study:
- To isolate and characterize the human homologue of mCD40-L (hCD40-L).
- To investigate the expression pattern and biological function of hCD40-L in B cell activation.
Main Methods:
- Isolation of hCD40-L cDNA from activated peripheral blood T cells using crosshybridization.
- Amino acid sequence prediction and comparison with mCD40-L.
- Northern blot and FACS analysis for expression studies.
- In vitro assays using transfected cells to assess B cell proliferation and immunoglobulin secretion.
Main Results:
- hCD40-L is a 261 amino acid type II membrane protein with 78% amino acid identity to mCD40-L.
- hCD40-L expression is restricted to T lymphocytes, predominantly on CD4+ T cells.
- Transfected hCD40-L induced human B cell proliferation without costimuli.
- hCD40-L, with IL-4, induced immunoglobulin E secretion from purified human B cells.
Conclusions:
- The human CD40 ligand (hCD40-L) has been identified and characterized.
- hCD40-L plays a significant role in T cell-mediated B cell activation, proliferation, and immunoglobulin secretion.
- hCD40-L is a key mediator in immune responses involving B lymphocytes.
Abstract:
Signaling through the cell surface molecule, CD40, is known to play an important role in the proliferation and differentiation of B lymphocytes. Using the thymoma cell line EL4, we recently identified and cloned a cDNA encoding a murine ligand for the CD40 molecule (mCD40-L) and showed that it has biological activity in vitro. A cDNA encoding a human homologue of the mCD40-L was isolated using crosshybridization techniques from an activated peripheral blood T cell library. The predicted amino acid sequence indicates that this human ligand for CD40 (hCD40-L) is a 261 amino acid type II membrane protein that exhibits 78% amino acid identity with its murine counterpart. Northern blot and FACS analyses suggest that the hCD40-L is restricted in its expression to T lymphocytes, and that it is most abundant on the CD4+ T cell subpopulation. Cells transfected with hCD40-L caused the proliferation of human tonsil B cells in the absence of costimuli and, in the presence of interleukin 4, induced immunoglobulin E secretion from purified human B cells. A comparison of the efficacy of the hCD40-L and mCD40-L in these assays is presented.
