Upstream Stimulating Factors Regulate the Expression of RORγT in Human Lymphocytes

Abstract

Retinoic acid-related orphan receptor γT (RORγT) is the orphan nuclear receptor that regulates the development of Th17 cells and the expression of IL-17. The differentiation of Th17 cells is associated with the upregulation of RORγT mRNA, and the mechanisms regulating that process in human cells are not well understood. We investigated the transcriptional regulation of RORγT in a human lymphocytic cell line and Th17 differentiated from naive CD4+ cells from human peripheral blood. A series of experiments, including 5′ deletion and in situ mutagenesis analysis of the human RORγT promoter, chromatin immunoprecipitation, and overexpression of selected transcription factors, revealed that the transcription factors upstream stimulatory factor 1 (USF-1) and USF-2 are indispensable for the transcription of RORγT in human lymphocytes. There was also upregulation of USF-1 and USF-2 during the differentiation of Th17 cells from naive CD4+ cells. In this article, we report the first analysis, to our knowledge, of the human RORγT promoter and demonstrate the role of the USF-1 and USF-2 transcription factors in regulating the expression of RORγT in human lymphocytes. Thus, USFs are important for the molecular mechanisms of Th17 differentiation, and possible changes in the expression of USFs might be of interest for inflammatory conditions with a Th17 component. Furthermore, these observations suggest a possible link between metabolic disorders in which the role of glucose-induced USF expression has already been established and autoimmune diseases in which the upregulation of RORγT is frequently detected.

The cytokine networks of adaptive immunity in fish

“…Differentiation of naive CD4þ lymphocytes into Th17 cells increases RORgt mRNA level through the collective action of a number of cytokines produced by APCs, including IL-1b, IL-6, IL-21, IL-23, and TGFb. The up-regulation of RORgt involves STAT3, IRF4, c-Rel, and upstream stimulatory factors [141]. Although the native ligand is unknown, the recent identification of small molecule inhibitors and activators of RORg that impair or enhance Th17 development further support its role in Th17 development [142].…”

Ubiquitination of RORγt at Lysine 446 Limits Th17 Differentiation by Controlling Coactivator Recruitment

“…It is thus important to understand the mechanisms regulating RORγt activity. Previous studies have focused on transcriptional regulation of RORγt and identification of RORγt target genes (6, 7, 14, 15). Less is known about the mechanisms of post-transcriptional regulation that is responsible for regulating RORγt function.…”

“…Mutation of the RORγt gene causes severe immunodeficiency in both mice (6) and humans (13). Because it is a transcription factor, most previous studies have focused on RORγt target genes critical for the regulation of Th17 differentiation, and have demonstrated that RORγt directly stimulates the expression of genes, including IL-17 (6, 7, 14, 15). However, little is known about the mechanisms responsible for post-transcriptional regulation of RORγt.…”

The immunomodulatory effects of TNF-α inhibitors on human Th17 cells via RORγt histone acetylation

“…Antibodies for the ChIP assay were purchased from Upstate Biotechnology Company. The primers were designed as previously described to analyse the promoter regions in the RORγt gene (forward: 5′-AGGCTGCACCACACTGG-3′, position: -599; reverse: 5′-TTCTACTCCTCCTACCCCCG-3′, position: -429) [43]. …”