GDF15 induces immunosuppression via CD48 on regulatory T cells in hepatocellular carcinoma

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.

Download Full-text

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

Cancers ◽

10.3390/cancers12113194 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3194

Author(s):

Pierre Stéphan ◽

Raphaëlle Lautraite ◽

Allison Voisin ◽

Yenkel Grinberg-Bleyer

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Treg Cell ◽

Transcriptional Control ◽

Molecular Mechanisms ◽

Treg Cells ◽

Multiple Strategies ◽

Cell Transcriptome ◽

And Function ◽

Novel Therapeutic

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.

Download Full-text

G Protein-Coupled Receptor 83 Is Dispensable for the Development and Function of Regulatory T Cells

Molecular and Cellular Biology ◽

10.1128/mcb.01075-07 ◽

2007 ◽

Vol 27 (23) ◽

pp. 8065-8072 ◽

Cited By ~ 16

Author(s):

Li-Fan Lu ◽

Marc A. Gavin ◽

Jeffrey P. Rasmussen ◽

Alexander Y. Rudensky

Keyword(s):

T Cells ◽

G Protein ◽

Treg Cell ◽

Cell Biology ◽

Molecular Mechanisms ◽

Foxp3 Expression ◽

Treg Cells ◽

G Protein Coupled Receptor ◽

And Function ◽

G Protein Coupled

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.

Download Full-text

Trichostatin A Promotes the Generation and Suppressive Functions of Regulatory T Cells

Clinical and Developmental Immunology ◽

10.1155/2013/679804 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 14

Author(s):

Cristian Doñas ◽

Macarena Fritz ◽

Valeria Manríquez ◽

Gabriela Tejón ◽

María Rosa Bono ◽

...

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Trichostatin A ◽

Gene Promoter ◽

Treg Cells ◽

Specific Subset ◽

Global Increase ◽

And Function ◽

H3 Acetylation

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.

Download Full-text

The Expression and Function of Circadian Rhythm Genes in Hepatocellular Carcinoma

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/4044606 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Yanan Jiang ◽

Xiuyun Shen ◽

Moyondafoluwa Blessing Fasae ◽

Fengnan Zhi ◽

Lu Chai ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Circadian Rhythm ◽

Circadian Rhythms ◽

Molecular Mechanisms ◽

Therapeutic Targets ◽

Pathogenic Mechanism ◽

Research Progress ◽

Biological Processes ◽

And Function ◽

Novel Therapeutic

Hepatocellular carcinoma (HCC) is among the most common and lethal form of cancer worldwide. However, its diagnosis and treatment are still dissatisfactory, due to limitations in the understanding of its pathogenic mechanism. Therefore, it is important to elucidate the molecular mechanisms and identify novel therapeutic targets for HCC. Circadian rhythm-related genes control a variety of biological processes. These genes play pivotal roles in the initiation and progression of HCC and are potential diagnostic markers and therapeutic targets. This review gives an update on the research progress of circadian rhythms, their effects on the initiation, progression, and prognosis of HCC, in a bid to provide new insights for the research and treatment of HCC.

Download Full-text

Metabolic reprogramming of human CD8+ memory T cells through loss of SIRT1

Journal of Experimental Medicine ◽

10.1084/jem.20161066 ◽

2017 ◽

Vol 215 (1) ◽

pp. 51-62 ◽

Cited By ~ 35

Author(s):

Mark Y. Jeng ◽

Philip A. Hull ◽

Mingjian Fei ◽

Hye-Sook Kwon ◽

Chia-Lin Tsou ◽

...

Keyword(s):

T Cells ◽

Molecular Mechanisms ◽

Memory T Cells ◽

Cell Metabolism ◽

Global Gene Expression ◽

Metabolic Reprogramming ◽

Transcriptional Reprogramming ◽

Age Related ◽

Global Gene Expression Profiling ◽

And Function

The expansion of CD8+CD28– T cells, a population of terminally differentiated memory T cells, is one of the most consistent immunological changes in humans during aging. CD8+CD28– T cells are highly cytotoxic, and their frequency is linked to many age-related diseases. As they do not accumulate in mice, many of the molecular mechanisms regulating their fate and function remain unclear. In this paper, we find that human CD8+CD28– T cells, under resting conditions, have an enhanced capacity to use glycolysis, a function linked to decreased expression of the NAD+-dependent protein deacetylase SIRT1. Global gene expression profiling identified the transcription factor FoxO1 as a SIRT1 target involved in transcriptional reprogramming of CD8+CD28– T cells. FoxO1 is proteasomally degraded in SIRT1-deficient CD8+CD28– T cells, and inhibiting its activity in resting CD8+CD28+ T cells enhanced glycolytic capacity and granzyme B production as in CD8+CD28– T cells. These data identify the evolutionarily conserved SIRT1–FoxO1 axis as a regulator of resting CD8+ memory T cell metabolism and activity in humans.

Download Full-text

CD4+ Foxp3+ regulatory T cell-mediated immunomodulation by anti-depressants inhibiting acid sphingomyelinase

Biological Chemistry ◽

10.1515/hsz-2018-0159 ◽

2018 ◽

Vol 399 (10) ◽

pp. 1175-1182 ◽

Cited By ~ 6

Author(s):

Jürgen Schneider-Schaulies ◽

Niklas Beyersdorf

Keyword(s):

T Cells ◽

T Cell ◽

Treg Cells ◽

Tricyclic Antidepressant ◽

Acid Sphingomyelinase ◽

Human T Cells ◽

And Function ◽

Rate Limiting ◽

Deficient Mice

AbstractAcid sphingomyelinase (ASM) is the rate-limiting enzyme cleaving sphingomyelin into ceramide and phosphorylcholin. CD4+Foxp3+regulatory T (Treg) cells depend on CD28 signaling for their survival and function, a receptor that activates the ASM. Both, basal and CD28-induced ASM activities are higher in Treg cells than in conventional CD4+T (Tconv) cells. In ASM-deficient (Smpd1−/−) as compared to wt mice, membranes of T cells contain 7–10-fold more sphingomyelin and two- to three-fold more ceramide, and are in a state of higher order than membranes of T cells from wt mice, which may facilitate their activation. Indeed, the frequency of Treg cells among CD4+T cells in ASM-deficient mice and their suppressive activityin vitroare increased. Moreover,in vitrostimulation of ASM-deficient T cells in the presence of TGF-β and IL-2 leads to higher numbers of induced Treg cells. Pharmacological inhibition of the ASM with a clinically used tricyclic antidepressant such as amitriptyline in mice or in tissue culture of murine or human T cells induces higher frequencies of Treg cells among CD4+T cells within a few days. This fast alteration of the balance between T cell populationsin vitrois due to the elevated cell death of Tconv cells and protection of the CD25highTreg cells by IL-2. Together, these findings suggest that ASM-inhibiting antidepressants, including a fraction of the serotonin re-uptake inhibitors (SSRIs), are moderately immunosuppressive and should be considered for the therapy of inflammatory and autoimmune disorders.

Download Full-text

Androgen receptor modulates Foxp3 expression in CD4+CD25+Foxp3+ regulatory T-cells

Molecular Biology of the Cell ◽

10.1091/mbc.e14-08-1323 ◽

2015 ◽

Vol 26 (15) ◽

pp. 2845-2857 ◽

Cited By ~ 51

Author(s):

Magdalena Walecki ◽

Florian Eisel ◽

Jörg Klug ◽

Nelli Baal ◽

Agnieszka Paradowska-Dogan ◽

...

Keyword(s):

T Cells ◽

Androgen Receptor ◽

Treg Cell ◽

Foxp3 Expression ◽

Treg Cells ◽

Strong Increase ◽

Histone H4 ◽

And Function

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.

Download Full-text

Enhanced IL-6 Production by Bone Marrow Derived Dendritic Cells from Lupus-Prone Mice Inhibits CD4+CD25+ T Cell Mediated Suppression.

Blood ◽

10.1182/blood.v108.11.1732.1732 ◽

2006 ◽

Vol 108 (11) ◽

pp. 1732-1732

Author(s):

Suigui Wan ◽

Changqing Xia ◽

Laurence Morel

Keyword(s):

Bone Marrow ◽

T Cells ◽

Dendritic Cells ◽

T Cell ◽

Neutralizing Antibody ◽

Susceptibility Loci ◽

Cell Compartment ◽

Systemic Autoimmunity ◽

Class Ii Mhc ◽

And Function

Abstract The B6.Sle1.Sle2.Sle3 triple congenic mouse (B6.TC) is a model of lupus due to the co-expression of the three major NZM2410-derived susceptibility loci on a C57BL/6 background. B6.TC mice produce high titers of anti-nuclear nephrogenic autoantibodies and a highly penetrant glomerulonephritis. Previous studies have shown the Sle1 locus is associated with a reduced number of regulatory T cells (Treg), and that Sle3 results in intrinsic defects in myeloid cells that hyperactivate T cells. Here, we show that B6.TC dendritic cells (DCs) accumulate in lymphoid organs and present a defective maturation process, in which bone-marrow derived DCs, plasmacytoid and myeloid DCs express a significantly lower level of CD80, CD86 and class II MHC than B6 controls. B6.TC DCs also induce a higher level of proliferation in CD4+ T cells than B6 DCs, and B6.TC DCs block the suppressive activity of Treg. B6.TC DCs over-produce IL-6, which is necessary for the blockade of Treg activity, as shown by anti-IL-6 neutralizing antibody in the suppression assays. The over-production of IL-6 by DCs and the blockade of Treg activity maps to Sle1, which therefore not only confers a reduced number of Treg, but also blocks their ability to regulate autoreactive T cells. Taken together, these results provide a genetic and mechanistic evidence for systemic autoimmunity resulting from an impaired regulatory T cell compartment both in number and function, and for Sle1-expressing DCs playing a major role in the latter defect though their production of IL-6.

Download Full-text

T Regulatory Cell Activation Exists in Pathogenesis of Polycythaemia Vera.

Blood ◽

10.1182/blood.v110.11.4642.4642 ◽

2007 ◽

Vol 110 (11) ◽

pp. 4642-4642

Author(s):

Xin Wang ◽

Wenbo Zhao ◽

Yanxia Liu ◽

Ying Li

Keyword(s):

T Cells ◽

T Cell ◽

Peripheral Blood ◽

Protein Level ◽

Treg Cells ◽

T Cell Immunity ◽

Polycythaemia Vera ◽

Cell Immunity ◽

And Function ◽

Hematopoietic Activity

Abstract Polycythaemia vera (PV) is a clonal disorder arising from a pluripotent hematopoietic progenitor cell. The etiology of PV remains unknown and there is no consensus as to the optimal therapy for this disorder. T regulatory (Treg) cells play a vital role in the maintenance of self-tolerance, control of auto-immunity and regulation of T-cell homeostasis, and they modulate overall immune responses against a variety of pathogens. Recent studies revealed that Treg cells play a crucial role in the process of hematopoietic activity. However, the effect of Treg cells in PV has not been reported. The Treg cells might participate in the dysfunction of T-cell immunity in PV. The profile and function of Treg cells in PV patients were explored in this study. Peripheral blood was withdrawn from 21 PV patients (Female 8 ; Male 13), as well as 25 age-matched healthy donors (F 9 ; M 16) as controls. All samples were taken after informed consent and collected from PV patients prior to treatment. Diagnoses of PV were made according to clinical and laboratory criteria. The peripheral blood mononuclear cells (PBMCs) were subjected to flow cytometry analyses after labeling with anti-CD4, anti-CD25, and anti-Foxp3 antibodies. Real-time PCR and Western blotting were also performed to identify quantitative FOXP3 mRNA expression and protein level in the PBMCs from PV in comparison to controls. The relationships between the percentage of Treg cells, the expressions for quantitative mRNA and protein, with the clinical data were assessed. The percentage of CD4+ T-cells was significant decreased in the group of PV than in normal control (28.7±7.07% vs 38.6±8.38%, p<0.05). But the percentage of CD4+CD25+FOXP3+ T-cells (Treg cells) in PV patients was significantly increased when compared to the control (10.93±4.02% vs 5.86±1.99%, p<0.05). Moreover, the quantitative mRNA expression of FOXP3 (64.23±18.52 vs 16.06±4.78, p<0.05) and protein expression of FOXP3 (0.74±0.16 vs 0.62±0.10, p<0.05)) were significantly enhanced in PV patients (shown in Figure 1). In conclusion, we showed that patients with PV have enhanced percentage of Treg cells in their peripheral blood. This was substantiated further with the finding that overexpressions of FOXP3 in PV both in mRNA and protein level. These results highlight important Treg-cell abnormalities in patients with PV because natural Treg cells are significantly increased in number and function. The underlying mechanism is still undefined, but the increased frequency and function of Treg cells might account for the abnormal T cell immunity in PV patients. It was suggested that there may be differently suppressive machanisms for Treg in these patients. The elevated Treg cells in PV might be activated and then affect the hematopoietic activity. We believe that Treg cells might involved in the dysfunction of T/NK cells in their disability to downregulate the hematopoietic proliferation in PV. And the expansion of Treg cells may be a feature of PV and associated with the pathogenesis of PV. Further investigation in this abnormality might provide novel therapy clue for this disease. Figure Figure

Download Full-text

Endogenous IL-β Selectively Converts T Regulatory Cells Into IL-17 Producers During Antigen Stimulation

Blood ◽

10.1182/blood.v116.21.586.586 ◽

2010 ◽

Vol 116 (21) ◽

pp. 586-586

Author(s):

Lequn Li ◽

Jin sub Kim ◽

Vassiliki A Boussiotis

Keyword(s):

T Cells ◽

T Regulatory Cells ◽

Neutralizing Antibody ◽

Treg Cells ◽

Conversion Process ◽

Regulatory Cells ◽

Antigen Stimulation ◽

Tnf Α ◽

Treg Population

Abstract Abstract 586 A major challenge of the immune system is to fight pathogens and tumor antigens while preserving tolerance to self-antigen. T regulatory cells (Treg) are critical extrinsic regulators of immune tolerance and maintenance of lymphoid homeostasis. Recently it was determined that, when used as cell-based immunosuppressive therapy, Treg have a potent effect in preventing GvHD in patients undergoing allogeneic stem cell transplantation. However, several studies suggest that the Treg phenotype is not at end stage of differentiation. Treg can express and produce effector cytokines including IFN-γ and IL-17 under certain conditions, particularly in the context of inflammatory milieu, suggesting that Treg may convert into inflammatory mediators. IL-1β and TNF-α are critical inflammatory cytokines that have been implicated in GvHD. The precise role and the mechanism(s) via which these cytokines may affect development of GvHD remain unclear. In the presence study, we sought to determine whether IL-1β and TNF-α regulate the properties of Treg and specifically whether these cytokines affect Treg expansion and/or conversion into IL-17 producing cells. CD4+CD25+Treg cells were isolated from B6 mice and were stimulated with anti-CD3-plus-anti-CD28 mAbs in the presence of either media, IL-1β or TNF-α. Addition of either cytokine induced Treg proliferation as determined by CFSE. Assessment of intracellular IL-17 expression by flow cytometry and IL-17 production by ELISA revealed that IL-1β but not TNF-α induced conversion of Treg into IL-17 producing cells, suggesting that conversion was mediated via pathways distinct from those that regulate cell cycle progression. To evaluate conversion of Treg to IL-17 producers during antigen stimulation and to determine the role of IL-1β in this process, we used neutral culture conditions in which no exogenous cytokines were supplied. Treg cells isolated from Foxp3GFP-KI mouse were added to cultures of naive conventional CD4+ T cells (Tc) in the presence of APC and anti-CD3 mAb. We found that these conditions preferentially induced conversion of Treg to IL-17 producing cells. To determine the role of IL-1β in this conversion process, we used IL-1β neutralizing antibody. Addition of anti-IL-1β neutralizing antibody reduced IL-17 production to almost undetectable levels. Because it has exogenous IL-6 can induce IL-17 production by both Treg and Tc, we evaluated whether endogenous IL-6 was involved in the conversion of Treg into IL-17 producing cells in our system. Addition of a combination of IL-6 neutralizing and IL-6 receptor blocking antibodies did not affect IL-17 production, suggesting that the conversion process of Treg into IL-17 producing cells was dependent on endogenous IL-1β rather than IL-6. To determine whether IL-1β was mandatory for this process, we used T cells from IL-1R deficient mice. Individual culture of IL−1R−/− Tc or IL-1R−/− Treg with wild type (wt) APC and co-culture of IL-1R−/− Tc and IL-1R−/− Treg with wt APC did not result in detectable IL-17 production. Similarly, no IL-17 production was observed when wt instead of IL-1R−/− Tc were used. In contrast, substitution of IL-1R−/− Treg with wt Treg resulted in abundant IL-17 production. To investigate the in vivo biological relevance of our findings we adoptively transferred Treg cells from either congenic B6.PL mice or IL-1R1−/− mice into IL-1R1−/− recipients, which were then immunized with KLH in IFA. Three days after immunization both IL-1R−/− Treg and IL-1R−/− Tc cells were incapable of producing detectable levels of IL-17 or expressing RORγt, the key transcriptional factor of IL-17. In contrast, a significant percentage of IL-17 and RORγt positive cells were detected within the adoptively transferred Thy1.1+ Treg population. Mechanistic analysis revealed that IL-1β induced activation of p38 and JNK in Treg and addition of pharmacologic inhibitors specific for these MAPKs abrogated IL-17 production. Our studies reveal that although Treg have primarily immunosuppressive functions they may also facilitate pro-inflammatory responses as they can be converted into IL-17 producing cells by IL-1β. These observations may have significant implications on clinical strategies that employ Treg for control of GvHD and suggest that further intervention might be required to prevent attainment of pro-inflammatory properties by Treg while maintaining their suppressive function. Disclosures: No relevant conflicts of interest to declare.

Download Full-text