Figure 6. Overexpression of T-bet or GATA3 in STAT-deficient Cells Fails to Reconstitute STAT-dependent Active Repertoires.

(A) GATA3 expression recovers half of STAT6-dependent elements in Th2 cells. Of 5,041 Th2-specific-STAT6-dependent p300 sites, 2,639 (50%) regulatory elements are recovered in STAT6-deficient cells in which GATA3 was reconstituted. Overall, 36% of Th2-specific enhancers are STAT6-dependent, GATA3-independent. Each column represents p300 binding in wild-type (Stat6^−/−) cells transduced with control or GATA3-expressing retrovirus centered on the Th2-specific p300 sites. Color-map corresponds to binding intensities where “black” represents no binding.

(B) GATA3 recovers p300 binding at genes whose expression levels are recovered by GATA3. Boxplots show median and quartiles of expression levels in RPKM (left) and normalized p300 binding in tag-per-million (right) in wild-type (Stat6^−/−) cells transduced with control or GATA3-expressing retrovirus at genes recovered by GATA3.

(C) GATA3 has no effect on p300 binding at genes whose expression levels are not affected by GATA3.

(D) T-bet overexpression fails to recover the chromatin signature of STAT4-dependent enhancers. Of 6,820 Th1-specific-STAT4-dependent sites, 1,614 (23%) regulatory elements are recovered in STAT4-deficient T-bet-expressing cells. Each column represents p300 binding in wild-type (Stat4^−/−) cells infected with control or T-bet-expressing retrovirus centered on the Th1-specific p300 sites.

(E) T-bet fails to recover p300 binding at genes whose expression levels are recovered by T-bet. Boxplots show median and quartiles of gene expression levels in RPKM (left) and normalized p300 binding in tag-per-million (right) in wild-type (Stat4^−/−) cells transduced with control or T-bet-expressing retrovirus.

(F) T-bet has no effect on p300 binding at genes whose expression levels are not recovered by T-bet.