Dlk1 influences differentiation and function of B lymphocytes.

The Dlk1 (delta-like-1) gene is a member of the epidermal growth factor (EGF)-like homeotic gene family. It influences cell-cell interactions between stromal cells and pro-B cells in vitro. To define the in vivo role of the dlk protein in B cell development, we established a Dlk1-/- mouse model.

Transforming growth factor-beta1 sensitivity is altered in Abl-Myc- and Raf-Myc-induced mouse pre-B-cell tumors.

Understanding the mechanisms leading to transformation of early B-lineage precursors is an important step leading to rational design of new treatments for precursor (pre)-B-cell leukemia. We used normal mouse pre-B cells to determine if and how transforming growth factor (TGF)-beta1 affects these precursors to the B-cell lineage and whether transformed pre-B cells respond to TGF-beta1. We found that normal pre-B cells proliferating in the presence of interleukin (IL)-7 enter cell-cycle arrest after exposure to TGF-beta1.