Notch Signaling Regulates Mouse and Human Th17 Differentiation

Meng

et al. 2016

Blood

Alloreactive T cells play a critical role in eliminating hematopoietic malignant cells but are also the mediators of graft-versus-host disease (GVHD), a major complication that subverts the success of allogeneic hematopoietic stem cell transplantation (HSCT). However, induction of alloreactive T cells does not necessarily lead to GVHD. Here we report the development of a cellular programming approach to render alloreactive T cells incapable of causing severe GVHD in both major histocompatibility complex (MHC)-mismatched and MHC-identical but minor histocompatibility antigen-mismatched mouse models. We

Section: Discussionmentioning

confidence: 99%

Programming of donor T cells using allogeneic δ-like ligand 4–positive dendritic cells to reduce GVHD in mice

Meng

et al. 2016

Blood

Laboratory Investigation

“…Our results are consistent with one recent study showing that specific inhibition of Notch1 expression through the use of Notch1 siRNA abrogates IL-17A and IL-17F production in polarized human Th17 cells. 39 However, DAPT did not significantly reduce the secretion of IL-21 in ITP patients. That may be because IL-21 can be produced by multiple effector CD4 þ T cells and NK T cells, and IL-21 production is RORgt independent as reported before.…”

Section: Discussionmentioning

confidence: 99%

Inactivation of Notch signaling reverses the Th17/Treg imbalance in cells from patients with immune thrombocytopenia

Liu

et al. 2015

T helper 17 (Th17) cells and regulatory T (Treg) cells, along with Th1 and Th2 cells, may contribute to the development of immune thrombocytopenia (ITP). The imbalance of Th17/Treg toward Th17 cells has been shown to play a pivotal role in the peripheral immune response. Notch signaling has been implicated in peripheral T-cell activation and effector cell differentiation. However, the role of Th17/Treg in the pathogenesis of ITP and the effect of Notch signaling on Th17/Treg imbalances remain largely elusive in ITP. In vitro, we treated peripheral blood mononuclear cells (PBMCs) from ITP and healthy controls with g-secretase inhibitor (DAPT). Th17 cells and Treg cells were measured by flow cytometry and IL-17, IL-21, and IL-10 secretion by enzyme immunoassay technique. The mRNA expression of Ntoch1, Hes1, Hey1, RORgt, and Foxp3 was investigated by RT-PCR. Cell proliferation and apoptosis were determined by the Cell Counting Kit-8 and apoptosis detection kit. We demonstrated that DAPT was effective in inhibiting mRNA expression of Notch signaling molecules. In untreated cultured PBMCs from ITP patients, we observed elevated Th17 cell and IL-21 levels and RORgt mRNA expression, decreased Treg cells and Foxp3 mRNA expression, and an increased ratio of Th17/Treg and RORgt/Foxp3. After inactivating Notch signal by DAPT, Th17 cells and Th17/Treg ratio were dose dependently decreased and accompanied by the reduction of IL-17 in culture supernatants and RORgt mRNA expression in ITP patients. However, no significant difference was found for Treg cells and Foxp3 mRNA expression, RORgt/Foxp3 ratio, and IL-21 and IL-10 levels after DAPT treatment in ITP patients. We also present evidence that the effect of DAPT inhibition on the Th17 cell response was associated with downregulation of RORgt and IL-17 transcription using human in vitro polarization. In conclusion, our findings highlight the importance of Notch signaling in Th17/Treg imbalances in ITP. Inactivation of Notch signaling might be a potential immunoregulatory strategy in ITP patients.

“…24 It has also been shown that inhibition of Notch signaling directly, and indirectly via regulation of RORC, turns down the production of IL17A. 25 RUNX1 interacts with FOXP3 and RORC, and is needed for Treg and Th17 cell function, respectively. 26,27 Calcitriol-activated VDR constrains IL17A transcription by inhibiting NFAT, recruiting HDAC, and sequestrating RUNX1.…”

Section: Org Frommentioning

confidence: 99%

Identification of early gene expression changes during human Th17 cell differentiation

Tuomela

Salo

Tripathi

et al. 2012

Blood

Th17 cells play an essential role in the pathogenesis of autoimmune and inflammatory diseases. Most of our current understanding on Th17 cell differentiation relies on studies carried out in mice, whereas the molecular mechanisms controlling human Th17 cell differentiation are less well defined. In this study, we identified gene expression changes characterizing early stages of human Th17 cell differentiation through genome-wide gene expression profiling. CD4 ؉ cells isolated from umbilical cord blood were used to determine detailed kinetics of gene expression after initiation of Th17 differentiation with IL1␤, IL6, and TGF␤. The differential expression of selected candidate genes was further validated at protein level and analyzed for specificity in initiation of Th17 compared with initiation of other Th subsets, namely Th1, Th2, and iTreg. This first genome-wide profiling of transcriptomics during the induction of human Th17 differentiation provides a starting point for defining gene regulatory networks and identifying new candidates regulating Th17 differentiation in humans. (Blood. 2012;119(23):e151-e160) IntroductionNaive CD4 ϩ T cells differentiate into functionally distinct lineages in response to environmental cues and interaction with APCs. The nature of invading pathogens determines the cytokine environment in which the cognate Ag recognition by TCR takes place, subsequently influencing the phenotype of differentiating CD4 ϩ Th cells. Classically, presentation of intra-or extracellular pathogens to naive T cells leads to either a Th1 response or a Th2 response, respectively. 1 Today, new functionally distinct subtypes of CD4 ϩ have been identified. 2 Since the original identification of IL17-secreting T cells, 3 further research has led to the definition of an effector Th17 cell lineage. [4][5][6] Shortly after these findings, Th17 cells were characterized also in humans by using peripheral blood T cells and T-cell clones derived from gut tissue of patients having Crohn disease. [7][8][9] Human Th17 cells express CCR6, CCR4, IL23R, and CD161 on their cell membrane. 9,10 The characteristic cytokine secreted by these cells is IL17A (also referred to as IL17). IL17A stimulates the secretion of wide range of proinflammatory chemokines and cytokines. As its receptor is widely expressed, many cells of the immune system as well as other cell types can respond to it. 11 In addition to IL17A, cytokines IL17F, IFN␥, IL22, and IL26 have been shown to be secreted by human Th17 cells. 7 Proper function of Th17 cells is needed for eradication of extracellular bacterial and fungal infections. 11 CD4 ϩ cells isolated from peripheral or cord blood have been used to examine Th17 polarization in human. In several studies, differentiation of naive cells from peripheral blood has not succeeded, or the IL17A production has been markedly less efficient than detected by memory cells. IL17A secretion of polarized cord blood cells is also modest. 12 Human Th17 cells have also been shown to originate from CD161 ϩ precursor cells...