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Updated: Aug 11, 2026
13:27
Generation of Human CD40-activated B cells
Published on: October 17, 2009
Functional CD40 ligand is expressed on epidermal Langerhans cells
C G Salgado1, K Nakamura, M Sugaya
1Department of Dermatology, The University of Tokyo, Japan.
Journal of Leukocyte Biology
|August 17, 1999
Summary
Epidermal Langerhans cells (LC) express CD40 ligand (CD40L) when cultured. This CD40L expression on LC modulates costimulatory molecules B7-1 and B7-2, crucial for immune responses.
Area of Science:
- Immunology
- Dermatology
- Cell Biology
Background:
- Langerhans cells (LC) are key antigen-presenting cells (APC) in the epidermis.
- LC express MHC class II and costimulatory molecules like B7-1 and B7-2.
- Cultured LC (cLC) express CD40, unlike freshly prepared LC (fLC), and TNF-alpha enhances this expression.
Purpose of the Study:
- To investigate the expression and function of CD40 ligand (CD40L) on epidermal Langerhans cells (LC).
- To determine if CD40L expression is modulated by cell culture or TNF-alpha.
- To assess the impact of CD40L on the expression of costimulatory molecules on LC.
Main Methods:
- Purification of murine epidermal Langerhans cells (LC).
- Culture of LC and treatment with TNF-alpha.
- Analysis of CD40 and CD40L expression using flow cytometry (FACS) and mRNA detection.
- Co-culture experiments with anti-CD40L antibody to assess functional impact.
Main Results:
- Both freshly prepared LC (fLC) and cultured LC (cLC) express CD40L mRNA.
- Only cLC express surface CD40L after 36 hours of culture; both fLC and cLC express cytoplasmic CD40L.
- TNF-alpha does not affect CD40L expression.
- Blocking CD40L markedly inhibits B7-1 and partially inhibits B7-2 expression on LC.
Conclusions:
- CD40L is expressed on cultured Langerhans cells (LC).
- LC-expressed CD40L plays a role in modulating the expression of costimulatory molecules B7-1 and B7-2.
- These findings highlight a novel regulatory mechanism involving CD40L on LC in immune cell interactions.
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