T-helper type 2 cell-specific expression of the ST2 gene is regulated by transcription factor GATA-3

ST2 is a member of the interleukin-1 receptor family and is expressed in type-2 T helper (Th2) cells. Here, we have studied the molecular mechanism responsible for the transcriptional regulation of the ST2 gene in Th2 cells using a mouse thymoma cell line, EL-4. The ST2 gene has distal and proximal promoters. ST2 mRNA was produced from the distal promoter in EL-4 cells stimulated with both phorbol 12-myristate 13-acetate (PMA) and dibutyryl cAMP (Bt2cAMP). The region of approximately 100 bp upstream of transcription start site, containing two GATA consensus sites, was indispensable for the activation of the distal promoter in reporter gene analysis. An electrophoretic mobility shift assay showed that transcription factor GATA-3 bound one of the GATA consensus sites (from −84 to −79) with nuclear extracts from PMA plus Bt2cAMP-stimulated EL-4 cells. The overexpression of GATA-3 enhanced the activity of the distal promoter. On the other hand, mutations of the GATA consensus site canceled out the enhancement by GATA-3. These data suggest that GATA-3 is an important transcription factor for the expression of the ST2 gene in Th2 cells.