Figure 8. STAT 5 regulates Igκ transcription and binds directly to E_κi.

Irf4^−/−Irf8^−/− pre-B cells expressing MIGR1, CA-STAT 5B or CA-Akt were cultured in medium with or without IL-7 for (a) 24 and (b–d) 48 hours. (a) qPCR analysis for Ccnd3 expression; ^†P<0.001 as compared with mock infected +IL-7 Ccnd3 expression and *P<0.001 as compared with mock infected −IL-7 Ccnd3 expression. B2m was used as the endogenous reference gene. Data represent mean ± SD from three independent experiments. (b) qPCR analysis for Igκ germline expression. ^†P<0.001 as compared with mock infected +IL-7 Igκ germline transcription and *P<0.001 as compared with mock infected −IL-7 Igκ germline transcription. B2m was used as the endogenous reference gene. Data represent mean ± SD from three independent experiments. (c) qPCR analysis shows Rag1 and Rag2 expression. ^†P<0.001 as compared with mock infected +IL-7 Rag1 (or Rag2) expression and *P<0.001 as compared with mock infected −IL-7 Rag1 (or Rag2) expression. B2m was used as the endogenous reference gene. Data represent mean ± SD from three independent experiments. (d) Irf4^−/−Irf8^−/− pre-B cells were cultured in medium with or without IL-7 for 48 hours and were subjected to ChIP assays with anti-STAT 5 antibodies. ^†P<0.001 as compared with binding of STAT 5 to E_κi with IL-7 and *P<0.001 as compared with binding of STAT 5 to Cish promoter. Data represent mean ± SD from three independent experiments. (e) Irf4^−/−Irf8^−/− pre-B cells expressing CA-STAT 5B or vector alone were cultured in medium with or without IL-7 for 24 hours and were subjected to ChIP assays with anti-E47 antibodies. ^†P<0.001 as compared with binding of E47 to E_ki without IL-7.