Chronic lymphocytic leukemia of Emu-TCL1 transgenic mice undergoes rapid cell turnover that can be offset by extrinsic CD257 to accelerate disease progression.

Results of heavy-water labeling studies have challenged the notion that chronic lymphocytic leukemia (CLL) represents an accumulation of noncycling B cells. We examined leukemia cell turnover in Emu-TCL1 transgenic (TCL1-Tg) mice, which develop a CLL-like disease at 8 to 12 months of age. We found that leukemia cells in these mice not only had higher proportions of proliferating cells but also apoptotic cells than did nonleukemic lymphocytes.