STAT4 ChIP-on-chip in IL12-Mediated T Helper 1 Cell Differentiation

The Signal Transducer and Activator of Transcription factor STAT4 is a critical component in the development of inflammatory adaptive immune responses. It has been extensively characterized as a lineage-determining factor in Th1 development. However, the genetic program activated by STAT4 that results in an inflammatory cell type is not well defined. In this report we use DNA isolated from STAT4-chromatin immunoprecipitation to perform ChIP-on-chip analysis of over 28,000 mouse gene promoters to identify STAT4 targets. We demonstrate that STAT4 binds multiple gene-sets that program distinct components of the Th1 lineage. While many STAT4 target genes display STAT4-dependent IL-12-inducible expression, other genes displayed IL-12-induced histone modifications but lack induction, possibly due to high relative basal expression. In the subset of genes that STAT4 programs for expression in Th1 cells, IL-12-induced mRNA levels remain increased for a longer time than mRNA from genes that are not programmed. This suggests that STAT4 binding to target genes, while critical, is not the only determinant for STAT4-dependent gene programming during Th1 differentiation. The supplementary bed file contains all 7504 Stat4 binding sites reported in the supplementary Analysis_results.xls Excel file. IL12-stimulated CD4+ T cell DNA ChIPed with Stat4 vs. Input DNA (2 replicates)