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PubMed · 7606868

CD40 ligand expression is developmentally regulated in human thymocytes.

R Fuleihan·D Ahern·R S Geha
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Abstract

Thymic selection involves the interaction between developing thymocytes and the thymic microenvironment. CD40 is expressed on thymic epithelial cells and on bone marrow-derived antigen-presenting cells in the thymus. We have investigated the capacity of human thymocytes to express CD40 ligand. CD40 ligand was not detectable on resting immature double-positive (CD4+/CD8+) or resting mature single-positive (CD4+/CD8- or CD4-/CD8+) thymocytes. Immature thymocytes failed to express CD40 ligand on their surface after stimulation with PMA and ionomycin, whereas stimulated CD4+/CD8- mature thymocytes expressed CD40 ligand. Northern blot analysis revealed that CD40 ligand mRNA was detectable in activated mature single-positive thymocytes. CD40 ligand expression by mature thymocytes was associated with the capacity to drive immunoglobulin isotype switching in purified B cells. These results demonstrate that the ability to express CD40 ligand is acquired late in thymocyte development and that mature thymocytes are capable of providing B cells with the activation signals necessary for immunoglobulin isotype switching.

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Antigens, CDB-LymphocytesBlotting, SouthernCD4-Positive T-LymphocytesCD40 LigandCD8-Positive T-LymphocytesChild, PreschoolFlow CytometryGene Expression RegulationHumansImmunoglobulin Class SwitchingImmunoglobulin EInfantLymphocyte ActivationMembrane GlycoproteinsRNA, MessengerT-Lymphocyte SubsetsThymus GlandJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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BibTeXRIS

R Fuleihan, D Ahern, R S Geha. 1995. CD40 ligand expression is developmentally regulated in human thymocytes.. https://doi.org/10.1006/clin.1995.1087

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