Tg8 mice develop T-ALL due to over-expression of Dll4 gene on T cells.

<p><b>A</b>) Enlarged hematopoietic organs (spleen, mesenteric lymph node and thymus) but not non-hematopoietic organ (kidney) of 4 month-old Tg8 mice compared with WT (left panel). Survival curve of Tg8 mice compared to WT and Tg5 mice (right panel). <b>B</b>) No obvert aneuploidy in Tg8 lymphomas. On the right panel, a metaphasic spread of one lymphoma; the left panel shows the chromosomes cut from the right side picture and positioned according to their size. Representative of 10 mice. <b>C</b>) Position and orientation of <i>TCRα</i> transgene and Dll4 gene in mouse Chromosome 2. <b>D</b>) Northern blot of Dll4 mRNA expression in Tg8 and WT thymocytes. The same membrane was reblotted with a probe of β actin as a loading control. <b>E</b>) qPCR analysis of Dll4 mRNA expression in Tg8 pre-tumoral thymus, spleen, mesenteric lymph nodes (mLN), skin, heart, kidney, liver and brain compared to WT mice. The abundance is calculated as the relative transcription normalized to β-actin expression fixed at 10,000 (left). <b>F</b>) DLL4 expression is restricted to αβ T cells. Flow cytometry analysis of DLL4 surface expression co-stained with anti-<i>αβ</i> TCR (<i>αβ</i> T cells), anti-<i>γδ</i> TCR (γδ T cells), anti-F4/80 (macrophages), anti-CD11c (dendritic cells), anti-CD19 (B cells) and anti-NK1.1 (NK cells), obtained from spleens of 4 week-old pre-tumoral Tg8 mice and WT littermates. Representative of 5 mice.