T-cell leukemia development in pre-TCR–deficient TEL-JAK2 transgenic mice. (A) Kaplan-Meier leukemia-free survival curves for EμSRα-TEL-JAK2 transgenic mice deficient or not for the Rag2 or Ptcra genes. The number of mice in each group is given in parentheses. The survival curves of Rag2- or Ptcra-deficient mice and the respective heterozygous littermates were significantly different (log-rank test, P < .001). Mice deceased from unrelated causes were censored in the analysis (tick marks). (B) Representative Rag2^+/− (no. 25) and Rag2^−/− (nos. 12, 22, and 1078) TEL-JAK2 leukemic cells and control thymocytes were double-stained with CD4 and CD8α antibodies (top panels) or stained with CD24 and CD25 antibodies (bottom panels) and analyzed by flow cytometry. (C) Kaplan-Meier T-cell leukemia survival curves for Cd3e^−/− and Rag2^−/− EμSRα-TEL-JAK2 mice. Mice deceased from B-cell lymphoma or other causes were censored in the analysis (tick marks). Note that no statistically significant difference in survival was observed between the 2 groups of mice (P = .98). (D) Tcrb locus Southern blot analysis of leukemic cell gDNA from Cd3e^−/− (nos. 71, 74, and 58) and Cd3e^+/+ (nos. 77 and 80) TEL-JAK2 thymic tumors. DNA obtained from wild-type liver (Liv), spleen (Spl), and thymus (Thy) was used as control. GL indicates the germline configuration and asterisks point to the distinct Tcrb locus clonal rearrangements. (E) Thymus, spleen, and lymph node weights were plotted for Cd3e^+/− (n = 12) and Cd3e^−/− (n = 10) TEL-JAK2 transgenic mice that developed T-cell leukemia/lymphoma. *P < .05 (unpaired t test). Average organ weight is indicated by horizontal bars.