Figure 1. Survivin expression is required for B cell development in the bone marrow.

(A) Survivin expression in: (1) pro- and large pre-B cells (CD43⁺, B220⁺, IgM⁻, IgD⁻), (2) small pre-B cells (CD43⁻, B220⁺, IgM⁻, IgD⁻), (3) immature B cells (CD43⁻, B220⁺, IgM⁺, IgD⁻), (4) mature recirculating cells (CD43⁻, B220⁺, IgM⁺, IgD⁺), (5) GC B cells (CD11c⁻, CD43⁻, IgD⁻) and (6) non GC B cells (CD11c⁻, CD43⁻, GL7⁻) determined by western blot. Actin was used as a loading control. One of two independent experiments is shown. (B) Survivin expression in (1) unstimulated B cells or treated with (2, 3) 10µg/mL anti-IgM (intact or F(ab’)₂ fragment, (4) 10 µg/mL LPS, (5) 5 µg/mL CpG (6) 5 µg/mL anti-CD40, (7) 25 ng/mL BAFF or (8) 100ng/mL APRIL (C) Flow cytometric analysis of splenocytes from survivin^L/Lmb1^Cre, survivin^L/+mb1^Cre, and survivin^+/+mb1^Cre mice with indicated antibodies. (D) Number of total splenocytes and splenic B cells from survivin^L/Lmb1^Cre, survivin^L/+mb1^Cre, and survivin^+/+mb1^Cre mice. (E) Flow cytometric analysis of early B cell compartment in the BM of survivin^L/Lmb1^Cre and survivin^+/+mb1^Cre mice. (F) Absolute numbers of B lineage cells at each stage of maturation in the BM of survivin^L/Lmb1^Cre and survivin^+/+mb1^Cre mice. (G) Cell cycle analysis of pro- and pre- B cells from survivin^L/Lmb1^Cre and survivin^+/+mb1^Cre mice. Results are representative of 2 independent experiments.