FIG. 10.

Survival effect of expression of active Stat5A on D1 cells following IL-7 withdrawal. (A) Nuclear proteins were prepared from D1 cells infected with parental retrovirus (EGFP) or with retrovirus harboring active Stat5A (stat5A) and subjected to Western blotting with a Flag antibody. (B) EGFP- or Stat5A-expressing cells were washed twice with PBS and cultured without mIL-7 for the indicated times. Percentages of viable cells were determined by PI staining. (C) EGFP (top)- or Stat5A (bottom)-expressing infected D1 cells were cultured with or without mIL-7 (50 ng/ml) for 48 h and stained with PI following flow-cytometric analysis. Percentages of G₁/G₀, S, G₂/M.and sub-G₁ cells are shown. Results show that activated Stat5 delayed death of D1 cells deprived of IL-7 but did not induce cell division.