A1 expression is stimulated by CD40 in B cells and rescues WEHI 231 cells from anti-IgM-induced cell death
✍ Scribed by Andreas W. Kuss; Matthias. Knödel; Friederike. Berberich-Siebelt; Dirk. Lindemann; Anneliese. Schimpl; Ingolf. Berberich
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 281 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0014-2980
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✦ Synopsis
Engagement of the antigen receptor on murine immature B cells leads to growth arrest followed by apoptosis. Concomitant signaling through CD40 sustains proliferation and rescues the cells from apoptosis. We show here that cross-linking CD40 stimulates the expression of A1, a member of the anti-apoptotic Bcl-2 family, in primary murine B lymphocytes. CD40dependent stimulation of A1 was confirmed in WEHI 231 cells, an immature murine B cell lymphoma line. We transduced WEHI 231 cells with a bicistronic recombinant retroviral vector coding for A1 and a chimeric selection marker comprising the enhanced yellow fluorescent protein and the zeocin resistance protein. A1-transduced WEHI 231 cells showed a significant higher survival rate after engagement of the antigen receptor. In contrast, constitutive expression of A1 did not abrogate anti-IgM-induced c-myc down-regulation. Consistant with this, A1 did not release anti-IgM-induced cell cycle arrest. Our data indicate that CD40stimulated A1 expression permits WEHI 231 cells to survive in the presence of anti-IgM antibodies and suggests a protective role for A1 in antigen receptor-mediated apoptosis in B cells.