Regulation of MZB cell development by Mib1 in the splenic microenvironment. (A) The lethally irradiated CD45.1 mice were injected i.v. with BM cells from the 12–15-wk-old MMTV-Cre;Mib1+/f (left) and MMTV-Cre;Mib1f/f (right) mice. At 12 wk after transplantation, the splenocytes were stained for the expression of CD21 and CD23 gated on the CD45.1+B220+ cells (top), CD1d and CD9 gated on the CD45.1+B220+ cells (middle), and CD21 and IgM gated on CD45.1+CD23− cells (bottom). Percentages indicated are mean ± SD from five independent experiments. (B) The lethally irradiated MMTV-Cre;Mib1+/f (left) and MMTV-Cre;Mib1f/f (right) mice (7–9 wk old) were transplanted with CD45.1 BM cells. At 5–6 wk after reconstitution with CD45.1 BM cells, the splenocytes were analyzed as in A. Percentages indicated are mean ± SD from five independent experiments. (C) Genomic DNA was prepared from the CD45− cells sorted from spleens and was analyzed by quantitative real-time PCR with deleted allele-specific primers. Data are mean ± SD from triplicate experiments. *, P < 0.0001.
