Expression of bcl-x during mouse B cell differentiation and following activation by various stimuli
| Autor: | Christopher J. Atkins, Michael S. K. Choi, Mary Holman, Gerry G. B. Klaus |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Male
X Chromosome Thapsigargin Immunology Naive B cell bcl-X Protein Apoptosis Lymphocyte Activation Mice chemistry.chemical_compound Proto-Oncogene Proteins medicine Animals Immunology and Allergy B cell B-Lymphocytes CD40 biology Cell Cycle Germinal center Cell Differentiation Cell cycle Molecular biology Mice Mutant Strains Cell biology Mice Inbred C57BL medicine.anatomical_structure Proto-Oncogene Proteins c-bcl-2 chemistry Mutation Mice Inbred CBA biology.protein Female Bone marrow |
| Zdroj: | European Journal of Immunology. 26:676-682 |
| ISSN: | 1521-4141 0014-2980 |
| DOI: | 10.1002/eji.1830260325 |
| Popis: | We have studied the expression of the novel anti-apoptotic protein bcl-x during mouse B cell differentiation and activation. We find that bcl-x is expressed throughout all stages of B cell differentiation in the bone marrow, and is only down-regulated in mature (sIgD+) B cells. Immature peripheral B cells express low levels of bcl-x even in adult animals, whereas mature resting B cells do not. Mature B cells re-express the protein following activation, achieving maximal levels after 36–48 h. The highest levels of bcl-x are observed with potent comitogenic stimuli (such as anti-CD40 + anti-Ig): B cells first express bcl-x in the G1 phase of the cell cycle and contain maximal levels in S phase. In addition, B cells from CBA/N mice, which do not proliferate when stimulated with anti-Ig, anti-CD40, or both, exhibited only low levels of the protein following culture with these stimuli. To investigate the functional significance of bcl-x in activated B cells, we tested their sensitivity to apoptosis induced by the Ca2+ ATPase inhibitor thapsigargin: B cell blasts activated with anti-CD40 and anti-Ig were resistant to this agent. The available data therefore suggest that bcl-x fulfils two roles in B cells: it promotes survival of immature B cells (which lack bcl-2) and secondly, it apparently plays an additional role in protecting activated mature B cells (perhaps those in germinal centers) from apoptotic stimuli. |
| Databáze: | OpenAIRE |
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