A subset of NP23 mice develop a CD19+B220−leukemia. (A) Schematic of the NP23 transgene. Vav 5′ and 3′ regulatory elements are indicated in red, the NUP98 portion of the transgene is gray, and the PHF23 portion is black, with the PHD domain indicated with crosshatches. (B) Schematic of murine bone marrow (BM) B-lymphopoietic differentiation stages, adapted from Hardy and Hayakawa.20 (C) Flow cytometry profile of I2 mouse BM, spleen, and lymph node, stained with the indicated antibodies. (D) Immunohistochemical staining of I2 BM with B220 antibody. (E) Representative flow cytometry profiles of BM, spleen, lymph node (LyNode), and thymus from NP-23 B-lineage ALL 752 using CD19 and B220 antibodies. (F) Hematoxylin and eosin (H&E), B220, and CD3 immunohistochemistry of infiltrated 752 spleen compared with a wild-type (WT) control. (G) B220/CD19 cell populations in additional pro–B-1 ALL samples. Analysis shown is of tissues with the highest purity of malignant cells: 633 BM, 724 BM, 758 BM, 1450 BM, 1533 LyNode, and 1534 BM. CLP, common lymphoid progenitor; Fr, fraction; HSC, hematopoietic stem cell; MLP, multilineage progenitor.
