Differential coupling of KLF10 to Sin3-HDAC and PCAF regulates the inducibility of the FOXP3 gene

Abstract

However, chromatin-mediated mechanisms that underlie these events in T regulatory cells remain to be fully characterized. Here, we report that inducibility of FOXP3, a key transcription factor for the development of T regulatory cells, depends upon Kruppel-like factor 10 (KLF10) interacting with two antagonistic histone-modifying systems. We utilized chromatin immunoprecipitation, genome-integrated reporter assays, and functional domain KLF10 mutant proteins, to characterize reciprocal interactions between this transcription factor and either the Sin3-histone deacetylase complex or the histone acetyltransferase, p300/CBP-associated factor (PCAF). We characterize a Sin3-interacting repressor domain on the NH2 terminus of KLF10, which works to limit the activating function of this transcription factor. Indeed, inactivation of this Sin3-interacting domain renders KLF10 able to physically associate with PCAF as to induce FOXP3 gene transcription. We show that this biochemical data derived from studying our genome-integrated reporter cell system are recapitulated in primary murine lymphocytes. Collectively, these results advance our understanding of how a single transcription factor, namely KLF10, functions as a toggle to integrate antagonistic signals regulating FOXP3 and, thus, immune activation.T regulatory cell; KLF10; PCAF; Sin3; FOXP3 FOXP3ϩ T REGULATORY (TREG) cells may develop outside the thymus, generally in response to transforming growth factor ␤ (TGF␤) and antigen to become critically important in intestinal immunologic homeostasis (adaptive Treg cells) (2,6,7,22,23,26). Dysregulation of the transcription factor FOXP3, a key initiator of the Treg differentiation and functional program, leads to immune dysregulation in both mice (scurfy mouse) and humans (IPEX-immune polyendocrinopathy enteritis and X-linked-syndrome) (16,38). While advances in T lymphocyte biology indicate the importance of TGF␤-induced activated T cells in both the induction (Th17 cells) and regulation (FOXP3ϩ Treg cells) of intestinal inflammation (3), the precise mechanistic events integrating the TGF␤ signal to intracellular pathways that function as inducers or regulators of inflammation are not fully defined.To identify these pathways, we recently characterized a role for a TGF␤-inducible Kruppel-like factor (KLF10) in silencing FOXP3 leading to enhanced colitis susceptibility, while providing mechanistic insights into how these functions require novel chromatin coupling events (40). These studies defined the importance of p300/CBP-associated factor (PCAF), a histone acetyltransferase (HAT) recruited by KLF10 to the FOXP3 transcriptional regulatory regions that are critical for the induction of this gene (40). In the experiments reported here, we build upon our previous discovery and demonstrate that KLF10 possesses the dual capacity to either positively or negatively regulate FOXP3 through its differential association with PCAF or the histone deacetylase binding protein Sin3, respectively. Collectively, these results increase our u...

Krüppel-like factor KLF10 deficiency predisposes to colitis through colonic macrophage dysregulation

“…Induction of DSS colitis was performed as previously described (7). To analyze the effect of bone marrow (BM) macrophage transfer to DSS colitis we transferred WT or KLF10 Ϫ/Ϫ BMDM 1 day prior and 1 day after the administration of DSS and followed the mice for disease activity and histological score (20,37).…”

“…Ϫ/Ϫ mice show enhanced susceptibility to colitis, partially through dysregulation of FOXP3 expression in Tregs (36,37). However, the precise cellular and molecular pathways, regarding the participation of other cell types in this process, are not fully characterized.…”

“…However, the precise cellular and molecular pathways, regarding the participation of other cell types in this process, are not fully characterized. We have recently shown that the susceptibility to DSS colitis in KLF10-deficient mice is transferable with BM (37). Given the importance of mucosal macrophages in colitis susceptibility in mice and humans, we reasoned that KLF10 deficiency in innate immune cells may contribute to colitis susceptibility through dysregulation of macrophages.…”

BRMS1L suppresses breast cancer metastasis by inducing epigenetic silence of FZD10

“…Among these complexes, the core switch-independent 3 (SIN3)-HDAC complex that integrates a wide variety of repressors and co-repressors are important inhibitors for cancer progression 5,6 . SIN3 is a scaffolding protein that was initially identified as a global regulator of gene transcription in yeast, whereas two isoforms have been found in mammals, Sin3A and Sin3B 7,8 .…”

Correlation between FOXP3 expression and gastric cancer

“…Transfection was performed according to the manufacturer's protocol. The positive clone group was formed after 3 weeks, then amplified, cultured and reserved (18).…”