Follicular B (FoB) cells purified from miR-17-92 transgenic mice

We have generated a miR-17-92 transgenic allele (termed miR-17-92 Tg) whose expression can be turned on conditionally by Cre recombinase (Xiao et al, Nature Immunology, 9:405-14, 2008). The mice were crossed to CD19-Cre mice to turn on the transgene expression specifically in B cells. Follicular B(FoB) cells were purified from CD19-Cre;miR-17~92 Tg/Tg mice (FoBtg1, FoBtg2, FoBtg3) and miR-17~92 Tg/Tg mice (FoBwt1, FoBwt2, FoBwt3) by MACS depletion of cells positive for CD5, CD43, and CD93 (also known as AA4.1). The purity of follicular B cells was examined by flow cytometry and was greater than 95% for all samples. Total RNA was extracted using RNeasy kit (QIAGEN).

我们构建了一种miR-17-92转基因等位基因，命名为miR-17-92 Tg，其表达可通过Cre重组酶（Cre recombinase）进行条件性激活（Xiao等，《自然·免疫学》，9:405-14，2008）。将该转基因小鼠与CD19-Cre小鼠杂交，使转基因仅在B细胞中特异性激活表达。通过磁激活细胞分选（MACS）耗竭CD5、CD43及CD93（亦称为AA4.1）阳性细胞，从CD19-Cre;miR-17~92 Tg/Tg小鼠（分组为FoBtg1、FoBtg2、FoBtg3）及miR-17-92 Tg/Tg小鼠（分组为FoBwt1、FoBwt2、FoBwt3）中纯化得到滤泡B细胞（Follicular B cells，FoB）。经流式细胞术（flow cytometry）检测，所有样本的滤泡B细胞纯度均高于95%。采用RNeasy试剂盒（QIAGEN公司）提取总RNA。