Abstract
The delivery of T-cell help to B cells is antigen-specific, MHC-restricted, and CD40L (CD154) dependent. It has been thought that when a T cell recognizes an antigen-presenting B cell, CD40L expressed on the T-cell surface engages with CD40 on the surface of B cells as long as the cells remain conjugated. By adding fluorescently labeled anti-CD40L antibody during overnight incubation of antigen-presenting B cells with antigen-specific T cells, we discovered that CD40L does not remain on the surface of the T cell, but it is transferred to and endocytosed by B cells receiving T-cell help. In the presence of anti-CD40L antibody, transferred CD40L is nearly absent on bystander B cells that are not presenting antigen, and the bystander cells do not become activated. Because transfer of CD40L to B cells correlates with B-cell activation, we speculate that persistence of helper T-cell-derived CD40L on or in B cells could permit sustained CD40 signaling enabling survival and proliferation of antigen-presenting B cells following brief interactions with helper T cells in vivo in germinal centers.
Original language | English (US) |
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Pages (from-to) | 41-50 |
Number of pages | 10 |
Journal | European Journal of Immunology |
Volume | 47 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 2017 |
Keywords
- CD154
- CD40 ligand
- CD40L
- Immunological synapse
- Membrane transfer
- T-cell help
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology