scholarly journals Transcriptional Control of Regulatory T Cells in Cancer: Toward Therapeutic Targeting?

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3194
Author(s):  
Pierre Stéphan ◽  
Raphaëlle Lautraite ◽  
Allison Voisin ◽  
Yenkel Grinberg-Bleyer

Extensive research in the past decades has highlighted the tight link between immunity and cancer, leading to the development of immunotherapies that have revolutionized cancer care. However, only a fraction of patients display durable responses to these treatments, and a deeper understanding of the cellular and mechanisms orchestrating immune responses to tumors is mandatory for the discovery of novel therapeutic targets. Among the most scrutinized immune cells, Forkhead Box Protein P3 (Foxp3)+ Regulatory T cells (Treg cells) are central inhibitors of protective anti-tumor immunity. These tumor-promoting functions render Treg cells attractive immunotherapy targets, and multiple strategies are being developed to inhibit their recruitment, survival, and function in the tumor microenvironment. In this context, it is critical to decipher the complex and multi-layered molecular mechanisms that shape and stabilize the Treg cell transcriptome. Here, we provide a global view of the transcription factors, and their upstream signaling pathways, involved in the programming of Treg cell homeostasis and functions in cancer. We also evaluate the feasibility and safety of novel therapeutic approaches aiming at targeting specific transcriptional regulators.

2007 ◽  
Vol 27 (23) ◽  
pp. 8065-8072 ◽  
Author(s):  
Li-Fan Lu ◽  
Marc A. Gavin ◽  
Jeffrey P. Rasmussen ◽  
Alexander Y. Rudensky

ABSTRACT Global analyses of gene expression in regulatory T (Treg) cells, whose development is critically dependent upon the transcription factor Foxp3, have provided many clues as to the molecular mechanisms these cells employ to control immune responses and establish immune tolerance. Through these studies, G protein-coupled receptor 83 (GPR83) was found to be expressed at high levels in Treg-cell populations. However, its function remained unclear. Recently, it has been suggested that GPR83 is involved in the induction of Foxp3 expression in the peripheral nonregulatory Foxp3− CD4 T cells. To examine a role for GPR83 in Treg-cell biology, we generated and characterized GPR83-deficient mice. We have shown that GPR83 abolition does not result in measurable pathology or changes in the numbers or function of Foxp3+ Treg cells. Furthermore, while in vitro analysis suggested a potential involvement of GPR83 in transforming growth factor β-dependent Foxp3 induction, there was no difference in the ability of nonregulatory GPR83-deficient and nondeficient Foxp3− T cells to acquire Foxp3 expression in vivo. Collectively, our results demonstrate that GPR83 is dispensable for Treg-cell development and function.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Cristian Doñas ◽  
Macarena Fritz ◽  
Valeria Manríquez ◽  
Gabriela Tejón ◽  
María Rosa Bono ◽  
...  

Regulatory T cells are a specific subset of lymphocytes that suppress immune responses and play a crucial role in the maintenance of self-tolerance. They can be generated in the thymus as well as in the periphery through differentiation of naïve CD4+T cells. The forkhead box P3 transcription factor (Foxp3) is a crucial molecule regulating the generation and function of Tregs. Here we show that thefoxp3gene promoter becomes hyperacetylated inin vitrodifferentiated Tregs compared to naïve CD4+T cells. We also show that the histone deacetylase inhibitor TSA stimulated thein vitrodifferentiation of naïve CD4+T cells into Tregs and that this induction was accompanied by a global increase in histone H3 acetylation. Importantly, we also demonstrated that Tregs generated in the presence of TSA have phenotypical and functional differences from the Tregs generated in the absence of TSA. Thus, TSA-generated Tregs showed increased suppressive activities, which could potentially be explained by a mechanism involving the ectonucleotidases CD39 and CD73. Our data show that TSA could potentially be used to enhance the differentiation and suppressive function of CD4+Foxp3+Treg cells.


2015 ◽  
Vol 26 (15) ◽  
pp. 2845-2857 ◽  
Author(s):  
Magdalena Walecki ◽  
Florian Eisel ◽  
Jörg Klug ◽  
Nelli Baal ◽  
Agnieszka Paradowska-Dogan ◽  
...  

CD4+CD25+Foxp3+ regulatory T (Treg) cells are able to inhibit proliferation and cytokine production in effector T-cells and play a major role in immune responses and prevention of autoimmune disease. A master regulator of Treg cell development and function is the transcription factor Foxp3. Several cytokines, such as TGF-β and IL-2, are known to regulate Foxp3 expression as well as methylation of the Foxp3 locus. We demonstrated previously that testosterone treatment induces a strong increase in the Treg cell population both in vivo and in vitro. Therefore we sought to investigate the direct effect of androgens on expression and regulation of Foxp3. We show a significant androgen-dependent increase of Foxp3 expression in human T-cells from women in the ovulatory phase of the menstrual cycle but not from men and identify a functional androgen response element within the Foxp3 locus. Binding of androgen receptor leads to changes in the acetylation status of histone H4, whereas methylation of defined CpG regions in the Foxp3 gene is unaffected. Our results provide novel evidence for a modulatory role of androgens in the differentiation of Treg cells.


2008 ◽  
Vol 76 (12) ◽  
pp. 5834-5842 ◽  
Author(s):  
Koichiro Watanabe ◽  
Varada P. Rao ◽  
Theofilos Poutahidis ◽  
Barry H. Rickman ◽  
Masahiro Ohtani ◽  
...  

ABSTRACT Cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) expressed at high levels by CD4+ CD25+ CD45RBlow regulatory T cells (Treg) is essential to their homeostatic and immunoregulatory functions. However, its relevance to anti-inflammatory roles of Treg in the context of colitogenic innate immune response during pathogenic bacterial infections has not been examined. We showed earlier in Rag2-deficient 129/SvEv mice that Treg cells are capable of suppressing colitis and colon cancer triggered by Helicobacter hepaticus, a widespread murine enterohepatic pathogen. Using this model, we now examined the effects of antibody blockade of CTLA-4 on Treg function during innate immune inflammatory response. Consistent with our previous findings, we found that a single adoptive transfer of Treg cells prior to infection prevented colitis development despite persistent H. hepaticus infection in recipient mice. However, when infected mice were injected with anti-CTLA-4 antibody along with Treg cell transfer, they developed a severe acute colitis with poor body condition that was not observed in Rag2−/− mice without Treg cell transfer. Despite high numbers of Foxp3+ Treg cells, evident by immunohistochemical analyses in situ, the CTLA-4 antibody-treated mice had severely inflamed colonic mucosa and increased rather than decreased expression levels of cytokines gamma interferon and interleukin-2. These findings indicate that antibody blockade of CTLA-4 clearly abrogates Treg cell ability to suppress innate immune-driven colitis and suggest that Treg cell CTLA-4 cognate interactions may be necessary to maintain homeostasis among cells of innate immunity.


2010 ◽  
Vol 207 (10) ◽  
pp. 2113-2125 ◽  
Author(s):  
Enguerran Mouly ◽  
Karine Chemin ◽  
Hai Vu Nguyen ◽  
Martine Chopin ◽  
Laurent Mesnard ◽  
...  

Regulatory T cells (T reg cells) constitute a population of CD4+ T cells that limits immune responses. The transcription factor Foxp3 is important for determining the development and function of T reg cells; however, the molecular mechanisms that trigger and maintain its expression remain incompletely understood. In this study, we show that mice deficient for the Ets-1 transcription factor (Ets-1−/−) developed T cell–mediated splenomegaly and systemic autoimmunity that can be blocked by functional wild-type T reg cells. Spleens of Ets-1−/− mice contained mostly activated T cells, including Th2-polarized CD4+ cells and had reduced percentages of T reg cells. Splenic and thymic Ets-1−/− T reg cells expressed low levels of Foxp3 and displayed the CD103 marker that characterizes antigen-experienced T reg cells. Thymic development of Ets-1−/− T reg cells appeared intrinsically altered as Foxp3-expressing cells differentiate poorly in mixed fetal liver reconstituted chimera and fetal thymic organ culture. Ets-1−/− T reg cells showed decreased in vitro suppression activity and did not protect Rag2−/− hosts from naive T cell–induced inflammatory bowel disease. Furthermore, in T reg cells, Ets-1 interacted with the Foxp3 intronic enhancer and was required for demethylation of this regulatory sequence. These data demonstrate that Ets-1 is required for the development of natural T reg cells and suggest a role for this transcription factor in the regulation of Foxp3 expression.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Reiko Takahashi ◽  
Akihiko Yoshimura

Several reports have suggested that natural regulatory T cells (Tregs) lose Forkhead box P3 (Foxp3) expression and suppression activity under certain inflammatory conditions. Treg plasticity has been studied because it may be associated with the pathogenesis of autoimmunity. Some studies showed that a minor uncommitted Foxp3+T cell population, which lacks hypomethylation at Treg-specific demethylation regions (TSDRs), may convert to effector/helper T cells. Suppressor of cytokine signaling 1 (SOCS1), a negative regulator of cytokine signaling, has been reported to play an important role in Treg cell integrity and function by protecting the cells from excessive inflammatory cytokines. In this review, we discuss Treg plasticity and maintenance of suppression functions in both physiological and pathological settings. In addition, we discuss molecular mechanisms of maintaining Treg plasticity by SOCS1 and other molecules. Such information will be useful for therapy of autoimmune diseases and reinforcement of antitumor immunity.


2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P178-P178
Author(s):  
Osama Alhamarneh ◽  
Nicholas D. Stafford ◽  
John Greenman

Problem To determine the correlation between peripheral blood CD4+CD25high regulatory T cells (Treg), a suppressor cell population that dampen the immune response, and clinical outcome and survival in HNSCC patients. Methods Treg cell numbers in the peripheral blood of newly-presenting, untreated HNSCC patients (n=65) were determined pre-operatively, 4–6 weeks after treatment (n=30) and in a cohort of healthy controls (n=35) of similar age and sex, after Treg cell isolation using magnetic microbeads (Miltenyi Biotec) by flow cytometry. The Mann-Whitney U test was used to analyse the correlations between Treg cell levels and clinical outcome. Results Treg cells were significantly higher in patients pre-operatively vs. controls (p=0.002). After treatment, patients showed a significant rise compared with their pre-treatment levels (p=0.022). Pre-treatment Treg cells levels did not correlate with survival or any of the other conventional clinicopathological parameters. However, higher Treg cells levels were discovered in the advanced disease stages (III/IV vs. I/II, median 6.3 vs 4.3) in the pre-treatment group that turned into significantly higher levels in the early disease stages post treatment (I/II vs. III/IV, median 10.8 vs. 5.67 p=0.044). Conclusion Although peripheral blood Treg cells levels were higher in patients when compared to controls, no correlation was found between this cell population and clinical outcome or survival. In contrast with gastric, colorectal and ovarian tumors, Treg cell levels did not normalize 4–6 weeks after curative treatment in this cohort of HNSCC patients. Studies into Treg cell function are thus required to try and elucidate the apparent paradox in Treg cell levels observed in HNSCC. Significance The presence of Regulatory T cells in the peripheral blood of HNSCC patients may be detrimental to host defence against tumor. Further studies are needed to explore their role in the tumor microenvironment and their correlation with clinical outcome.


2021 ◽  
Author(s):  
Mark Mensink ◽  
Ellen Schrama ◽  
Maartje van den Biggelaar ◽  
Derk Amsen ◽  
Jannie Borst ◽  
...  

The CD4+ regulatory T (Treg) cell lineage, as defined by FOXP3 expression, comprises thymus-derived (t)Treg cells and peripherally induced (p)Treg cells. In human, naive tTreg cells can be purified from blood, but occur in low abundance, while effector pTreg and tTreg cell populations cannot be purified for lack of discriminating cell surface markers. Therefore, studies often employ TGF-β-induced (i)Treg cells that are generated from CD4+ conventional T (Tconv) cells in vitro. Here, we describe the relationship of iTreg cells to tTreg and Tconv cells, as optimally purified from human blood. Global proteomic analysis revealed that iTreg, tTreg and Tconv cell populations each have a unique protein expression pattern. We next used as a benchmark a previously defined proteomic signature that discerns ex vivo naive and effector phenotype Treg cells from Tconv cells and reflects unique Treg cell properties. This Treg cell core signature was largely absent from iTreg cells, while clearly present in simultaneously analyzed tTreg cells. In addition, we used a proteomic signature that distinguishes ex vivo effector Treg cells from Tconv cells and naive Treg cells. This effector Treg cell signature was partially present in iTreg cells. Thus, iTreg cells are distinct from tTreg cells and largely lack the common Treg cell proteomic signature. However, they do have certain protein expression features in common with ex vivo effector Treg cells. These data demonstrate the utility of the core and effector Treg cell signatures as tools to define Treg cell populations and encourage the use of ex vivo Treg cells for functional analyses.


2021 ◽  
Vol 9 (9) ◽  
pp. e002787
Author(s):  
Zhaowei Wang ◽  
Lei He ◽  
Weina Li ◽  
Chuanyang Xu ◽  
Jieyu Zhang ◽  
...  

BackgroundA better understanding of the molecular mechanisms that manifest in the immunosuppressive tumor microenvironment (TME) is crucial for developing more efficacious immunotherapies for hepatocellular carcinoma (HCC), which has a poor response to current immunotherapies. Regulatory T (Treg) cells are key mediators of HCC-associated immunosuppression. We investigated the selective mechanism exploited by HCC that lead to Treg cells expansion and to find more efficacious immunotherapies.MethodsWe used matched tumor tissues and blood samples from 150 patients with HCC to identify key factors of Treg cells expansion. We used mass cytometry (CyTOF) and orthotopic cancer mouse models to analyze overall immunological changes after growth differentiation factor 15 (GDF15) gene ablation in HCC. We used flow cytometry, coimmunoprecipitation, RNA sequencing, mass spectrum, chromatin immunoprecipitation and Gdf15–/–, OT-I and GFP transgenic mice to demonstrate the effects of GDF15 on Treg cells and related molecular mechanism. We used hybridoma technology to generate monoclonal antibody to block GDF15 and evaluate its effects on HCC-associated immunosuppression.ResultsGDF15 is positively associated with the elevation of Treg cell frequencies in patients wih HCC. Gene ablation of GDF15 in HCC can convert an immunosuppressive TME to an inflammatory state. GDF15 promotes the generation of peripherally derived inducible Treg (iTreg) cells and enhances the suppressive function of natural Treg (nTreg) cells by interacting with a previously unrecognized receptor CD48 on T cells and thus downregulates STUB1, an E3 ligase that mediates forkhead box P3 (FOXP3) protein degradation. GDF15 neutralizing antibody effectively eradicates HCC and augments the antitumor immunity in mouse.ConclusionsOur results reveal the generation and function enhancement of Treg cells induced by GDF15 is a new mechanism for HCC-related immunosuppression. CD48 is the first discovered receptor of GDF15 in the immune system which provide the possibility to solve the molecular mechanism of the immunomodulatory function of GDF15. The therapeutic GDF15 blockade achieves HCC clearance without obvious adverse events.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Viviana Volta ◽  
Sandra Pérez-Baos ◽  
Columba de la Parra ◽  
Olga Katsara ◽  
Amanda Ernlund ◽  
...  

AbstractRegulatory T cells (Treg cells) inhibit effector T cells and maintain immune system homeostasis. Treg cell maturation in peripheral sites requires inhibition of protein kinase mTORC1 and TGF-beta-1 (TGF-beta). While Treg cell maturation requires protein synthesis, mTORC1 inhibition downregulates it, leaving unanswered how Treg cells achieve essential mRNA translation for development and immune suppression activity. Using human CD4+ T cells differentiated in culture and genome-wide transcription and translation profiling, here we report that TGF-beta transcriptionally reprograms naive T cells to express Treg cell differentiation and immune suppression mRNAs, while mTORC1 inhibition impairs translation of T cell mRNAs but not those induced by TGF-beta. Rather than canonical mTORC1/eIF4E/eIF4G translation, Treg cell mRNAs utilize the eIF4G homolog DAP5 and initiation factor eIF3d in a non-canonical translation mechanism that requires cap-dependent binding by eIF3d directed by Treg cell mRNA 5’ noncoding regions. Silencing DAP5 in isolated human naive CD4+ T cells impairs their differentiation into Treg cells. Treg cell differentiation is mediated by mTORC1 downregulation and TGF-beta transcriptional reprogramming that establishes a DAP5/eIF3d-selective mechanism of mRNA translation.


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