| Autor: |
S L, Parry, J, Hasbold, M, Holman, G G, Klaus |
| Rok vydání: |
1994 |
| Předmět: |
|
| Zdroj: |
Journal of immunology (Baltimore, Md. : 1950). 152(6) |
| ISSN: |
0022-1767 |
| Popis: |
Cross-linking of sIgM or sIgD receptors on mature B cells with appropriate anti-Ig Abs normally induces B cell activation and DNA synthesis. We show here that hypercross-linking of either class of sIg receptor on these cells by biotinylated, normally mitogenic anti-mu or anti-delta mAb by avidin rapidly induces unresponsiveness to heterologous anti-Ig, accompanied by DNA fragmentation characteristic of apoptosis. Apoptotic nuclei can be detected within 4 h after stimulation, but cells that survive for 12 to 16 h are abortively activated, as evidenced by increased levels of MHC class II Ags. Because the induction of B cell tolerance is known to be modulated by T cell-derived influences, we investigated the effects of two stimuli--IL-4 and ligation of CD40--that are known to affect B cell survival in this system. IL-4 partially reversed the induction of apoptosis, as did a mAb to CD40, and both reagents together caused almost complete reversal. We therefore conclude that in the absence of T cell help the extent of sIg receptor cross-linking on mature B cells determines whether the cells enter cycle or become deleted. We believe that this system represents a polyclonal model of clonal deletion of mature B cells induced by highly cross-linking Ags, such as type 2 T-independent polysaccharide Ags. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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