Abstract
Clonal anergy of autoreactive B cells is a key mechanism regulating tolerance. Here, we show that anergic B cells express significant surface levels of CD5, a molecule normally found on T cells and a subset of B-1 cells. Breeding of the hen egg lysozyme (HEL) transgenic model for B cell anergy onto the CD5 null background resulted in a spontaneous loss orb cell tolerance in vivo. Evidence for this included elevated levels of anti-HEL immunoglobulin M (IgM) antibodies in the serum of CD5(-/-) mice transgenic for both an HEL-specific B cell receptor (BCR) and soluble lysozyme. 'Anergic' B cells lacking CD5 also showed enhanced proliferative responses in vitro and elevated intracellular Ca2+ levels at rest and after IgM cross-linking. These data support the hypothesis that CD5 negatively regulates Ig receptor signaling in anergic B cells and functions to inhibit autoimmune B cell responses.
Original language | English (US) |
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Pages (from-to) | 883-889 |
Number of pages | 7 |
Journal | Journal of Experimental Medicine |
Volume | 191 |
Issue number | 5 |
DOIs | |
State | Published - Mar 6 2000 |
Keywords
- Anergy
- B cell
- CD5
- Hen egg lysozyme
- Signal transduction