STAT5 phosphorylation in Stat5b transgenic mice.

<p>(A) Representative Western blotting analysis for phosphorylated and total STAT5 in F1 and NOD Stat5b transgenic lines. These mice did not have detectable signs of lymphoma based on physical examination and FACS analysis of T cell phenotypes. Protein extracts from thymus were used for the experiment. (B) Representative Western blotting analysis of phosphorylated STAT5 with thymus protein extracts from NOD.Stat5b transgenic mice with lymphoma. (C) STAT5 phosphorylation status in different cell types. Thymocytes and splenocytes from NOD Stat5b^Tg mice were analyzed by intracellular staining for phosphorylated STAT5 with an anti–pTyr694-STAT5 antibody. (D) FACS analysis showing progressive increase of STAT5 phosphorylation in thymocytes of NOD.Stat5b^Tg mice. Data for thymus are shown here for 6, 12 and 16 week old NOD.Stat5b^Tg mice (all without tumor). Representative data are shown from 1 of 3 similar experiments.</p

Total cell numbers in the thymus, bone marrow and spleen of NOD.Stat5b transgenic mice and littermate controls.

<p>Cell numbers (10⁶) are the averages for NOD.Stat5b^Tg transgenic mice and their non-transgenic littermate control mice (LMC). Mice at 6 weeks (6 wk), 10 weeks (10 wk) and 16 weeks (16 wk) of age were examined. Student t tests were used to assess statistical significance.</p>#<p>, <i>P</i>>0.05;</p>*<p>, <i>P</i><0.05;</p>**<p>, <i>P</i><0.01 compared with LMC.</p

Phenotypes of CD8⁺ lymphomas and T cell development in NOD.Stat5b^Tg mice.

<p>(A) Three different types of lymphoma cells are illustrated. The vast majority of lymphomas (57/60) are similar to the Onco 2 mouse, e.g., with CD4⁺CD8⁺ double positive and CD8⁺ single positive thymocytes. Two mice with lymphomas had predominantly CD8⁺ single-positive thymocytes (Onco 18) and one mouse had predominantly CD4⁺CD8⁺ double-positive thymocytes (Onco 29). (B) Phenotypes of metastatic tumors. Tumor phenotypes are identical in different lymphoid organs including spleen (SP), thymus (Thy) and cervical lymph node (CN) (a, b, c). Tumor cells (5×10⁶) from thymus of the mouse as shown in b were subcutaneously injected at the back of regular NOD mice. Tumor formation was observed at the site of injection 10–20 days later and tumor cells also migrate to other lymphoid organs including spleen (d), thymus (e) and cervical node (f). Tumor phenotypes are identical at the injection site (g, dorsal) and other lymphoid organs. (C) CD25 expression in thymus of NOD.Stat5b^Tg mice and littermate controls at 6 weeks and lymphoma population in cervical node. (D) T cell phenotypes in the thymus (Thy) and spleen (Sp) of NOD.Stat5b^Tg mice and littermate controls at 6 weeks (6 w) and 12 weeks (12 w) of age. (E) T cell phenotypes in the thymus (Thy) and spleen (Sp) of NOD/B6 F1.Stat5b^Tg mice and littermate controls at 6 weeks (6 w) and 12 weeks (12 w) of age. (F) CD44 and CD122 expression of CD8⁺ T cells from spleens and thymi of NOD.Stat5b^Tg mice (16 weeks of age). Representative data are shown from 1 of 4 similar experiments.</p

Lymphoblastic lymphoma in Stat5b transgenic mice.

<p>(A) Progression of lymphoma observed in the B6xNOD F1.Stat5b^Tg mice and NOD.Stat5b^Tg mice with or without chemoprevention treatment. The lymphoma incidence is significantly different between F1 mice and NOD.Stat5b^Tg mice (p<0.001). (B) Overview of a mouse that has enlarged thymus, spleen, and lymph nodes (left panel). Enlarged spleen (SP), cervical lymph node (CN) and thymus (Thy) are compared to littermate controls (right panel). **, p<0.01, compared with that of littermate controls. (C) H&E staining of spleen, cervical node and thymus from a NOD.Stat5b^Tg mouse with lymphoma and its littermate control (LMC). Scale bars represent 50 um.</p