Molecular analysis of a locus control region in the T helper 2 cytokine gene cluster: a target for STAT6 but not GATA3.
The linked IL-4 and IL-13 cytokine genes, which are activated and silenced in T helper (Th) 2 and Th1 cells, respectively, are flanked by the equivalently expressed RAD50 and KIF3A genes. A scan of DNase I hypersensitivity and DNA methylation across approximately 100 kb of the KIF3A/IL-4/IL-13/RAD50 cluster revealed differences in chromatin structure between Th1 and Th2 cells at the 3' end of the RAD50 gene, a region previously shown to contain a locus control region (LCR) regulating Th2-specific expression of IL-4 and IL-13. Naive CD4 T cells did not exhibit any DNase I hypersensitivity in this region, but stimulation under either Th1 or Th2 conditions caused rapid development of three hypersensitive sites. An additional hypersensitive site developed rapidly only under Th2 conditions, through a mechanism dependent on signal transducers and activators of transcription 6 (STAT6) but not GATA3. Our data point to a physical separation in the actions of STAT6 and its downstream effector GATA3 during Th2 differentiation: STAT6 directly remodels the RAD50 LCR, whereas GATA3 acts only in the vicinity of the IL-4 gene. We suggest that the RAD50 LCR has a complex and dual role in Th1 and Th2 differentiation, communicating early T cell antigen receptor and cytokine signals to the IL-4/IL-13 locus in both differentiating cell types.
Lee
Dong U
DU
Department of Pathology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
Rao
Anjana
A
D000818:Animals; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050990:GATA3 Transcription Factor; D018793:Interleukin-13 / Q000235:genetics*; D015847:Interleukin-4 / Q000235:genetics*; D019901:Locus Control Region; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D005810:Multigene Family; D050800:STAT6 Transcription Factor; D015398:Signal Transduction; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology; D018418:Th2 Cells / Q000166:cytology / Q000276:immunology; D015534:Trans-Activators / Q000378:metabolism*
D004268:DNA-Binding Proteins; D050990:GATA3 Transcription Factor; C494748:Gata3 protein, mouse; D018793:Interleukin-13; D050800:STAT6 Transcription Factor; C494100:Stat6 protein, mouse; D015534:Trans-Activators; D015847:Interleukin-4