ABSTRACT
Approximately 25% of cancers are preceded by chronic inflammation that occurs at the site of tumor development. However, whether this multifactorial oncogenic process, which commonly occurs in the intestines, can be initiated by a specific immune cell population is unclear. Here, we show that an intestinal T cell subset, derived from interleukin-17 (IL-17)-producing helper T (TH17) cells, induces the spontaneous transformation of the intestinal epithelium. This subset produces inflammatory cytokines, and its tumorigenic potential is not dependent on IL-17 production but on the transcription factors KLF6 and T-BET and interferon-γ. The development of this cell type is inhibited by transforming growth factor-ß1 (TGFß1) produced by intestinal epithelial cells. TGFß signaling acts on the pretumorigenic TH17 cell subset, preventing its progression to the tumorigenic stage by inhibiting KLF6-dependent T-BET expression. This study therefore identifies an intestinal T cell subset initiating cancer.
ABSTRACT
Tissue-resident memory T (TRM) cells, functionally distinct from circulating memory T cells, have a critical role in protective immunity in tissues, are more efficacious when elicited after vaccination and yield more effective antitumor immunity, yet the signals that direct development of TRM cells are incompletely understood. Here we show that type 1 regulatory T (Treg) cells, which express the transcription factor T-bet, promote the generation of CD8+ TRM cells. The absence of T-bet-expressing type 1 Treg cells reduces the presence of TRM cells in multiple tissues and increases pathogen burden upon infectious challenge. Using infection models, we show that type 1 Treg cells are specifically recruited to local inflammatory sites via the chemokine receptor CXCR3. Close proximity with effector CD8+ T cells and Treg cell expression of integrin-ß8 endows the bioavailability of transforming growth factor-ß in the microenvironment, thereby promoting the generation of CD8+ TRM cells.
Subject(s)
CD8-Positive T-Lymphocytes/immunology , Cell Communication/immunology , Cell Differentiation/immunology , Immunologic Memory , T-Lymphocytes, Regulatory/immunology , Adoptive Transfer , Animals , CD8-Positive T-Lymphocytes/transplantation , Coccidiosis/immunology , Coccidiosis/parasitology , Disease Models, Animal , Eimeria/immunology , Female , Humans , Integrin beta Chains/metabolism , Male , Mice , Mice, Transgenic , Receptors, CXCR3/metabolism , T-Box Domain Proteins/genetics , T-Box Domain Proteins/metabolism , T-Lymphocytes, Regulatory/metabolism , T-Lymphocytes, Regulatory/transplantation , Transforming Growth Factor beta/metabolismABSTRACT
Establishing and maintaining tolerance to self-antigens or innocuous foreign antigens is vital for the preservation of organismal health. Within the thymus, medullary thymic epithelial cells (mTECs) expressing autoimmune regulator (AIRE) have a critical role in self-tolerance through deletion of autoreactive T cells and promotion of thymic regulatory T (Treg) cell development1-4. Within weeks of birth, a separate wave of Treg cell differentiation occurs in the periphery upon exposure to antigens derived from the diet and commensal microbiota5-8, yet the cell types responsible for the generation of peripheral Treg (pTreg) cells have not been identified. Here we describe the identification of a class of RORγt+ antigen-presenting cells called Thetis cells, with transcriptional features of both mTECs and dendritic cells, comprising four major sub-groups (TC I-TC IV). We uncover a developmental wave of Thetis cells within intestinal lymph nodes during a critical window in early life, coinciding with the wave of pTreg cell differentiation. Whereas TC I and TC III expressed the signature mTEC nuclear factor AIRE, TC IV lacked AIRE expression and was enriched for molecules required for pTreg generation, including the TGF-ß-activating integrin αvß8. Loss of either major histocompatibility complex class II (MHCII) or ITGB8 by Thetis cells led to a profound impairment in intestinal pTreg differentiation, with ensuing colitis. By contrast, MHCII expression by RORγt+ group 3 innate lymphoid cells (ILC3) and classical dendritic cells was neither sufficient nor required for pTreg generation, further implicating TC IV as the tolerogenic RORγt+ antigen-presenting cell with an essential function in early life. Our studies reveal parallel pathways for the establishment of tolerance to self and foreign antigens in the thymus and periphery, respectively, marked by the involvement of shared cellular and transcriptional programmes.
Subject(s)
Antigen-Presenting Cells , Dendritic Cells , Epithelial Cells , Gastrointestinal Microbiome , Immune Tolerance , T-Lymphocytes, Regulatory , Thymus Gland , Cell Differentiation , Dendritic Cells/immunology , Dendritic Cells/metabolism , Epithelial Cells/immunology , Epithelial Cells/metabolism , Gastrointestinal Microbiome/immunology , Immunity, Innate , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , Thymus Gland/cytology , Thymus Gland/immunology , Transforming Growth Factor beta/immunology , Antigen-Presenting Cells/immunology , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/pathology , Lymph Nodes/immunologyABSTRACT
Both identity and plasticity of CD4 T helper (Th) cells are regulated in part by epigenetic mechanisms. However, a method that reliably and readily profiles DNA base modifications is still needed to finely study Th cell differentiation. Cytosine methylation in CpG context (5mCpG) and cytosine hydroxymethylation (5hmCpG) are DNA modifications that identify stable cell phenotypes, but their potential to characterize intermediate cell transitions has not yet been evaluated. To assess transition states in Th cells, we developed a method to profile Th cell identity using Cas9-targeted single-molecule nanopore sequencing. Targeting as few as 10 selected genomic loci, we were able to distinguish major in vitro polarized murine T cell subtypes, as well as intermediate phenotypes, by their native DNA 5mCpG patterns. Moreover, by using off-target sequences, we were able to infer transcription factor activities relevant to each cell subtype. Detection of 5mCpG and 5hmCpG was validated on intestinal Th17 cells escaping transforming growth factor ß control, using single-molecule adaptive sampling. A total of 21 differentially methylated regions mapping to the 10-gene panel were identified in pathogenic Th17 cells relative to their nonpathogenic counterpart. Hence, our data highlight the potential to exploit native DNA methylation profiling to study physiological and pathological transition states of Th cells.
Subject(s)
DNA Methylation , Epigenesis, Genetic , Animals , Mice , Cytosine , DNA/metabolism , Th17 Cells/metabolismABSTRACT
Regulatory T (Treg) cells play a pivotal role in suppressing self-harmful T cell responses, but how Treg cells mediate suppression to maintain immune homeostasis and limit responses during inflammation is unclear. Here we show that effector Treg cells express high amounts of the integrin αvß8, which enables them to activate latent transforming growth factor-ß (TGF-ß). Treg-cell-specific deletion of integrin αvß8 did not result in a spontaneous inflammatory phenotype, suggesting that this pathway is not important in Treg-cell-mediated maintenance of immune homeostasis. However, Treg cells lacking expression of integrin αvß8 were unable to suppress pathogenic T cell responses during active inflammation. Thus, our results identify a mechanism by which Treg cells suppress exuberant immune responses, highlighting a key role for effector Treg-cell-mediated activation of latent TGF-ß in suppression of self-harmful T cell responses during active inflammation.
Subject(s)
Inflammation/immunology , Integrins/metabolism , T-Lymphocytes, Regulatory/immunology , Transforming Growth Factor beta/immunology , Animals , Cell Proliferation , Colitis/immunology , Disease Models, Animal , Gene Expression Regulation/immunology , Humans , Inflammation Mediators/immunology , Integrins/genetics , Mice , Models, Immunological , T-Lymphocytes, Regulatory/cytologyABSTRACT
Memory CD8(+) T cells induced upon immunization exhibit improved functional features that contribute to protection of immunized hosts. Although both cognate antigen recognition and inflammation are important for memory CD8(+) T cell reactivation, the relative contribution of these factors and the cell types providing these signals in vivo are poorly defined. Here, we show that Ly6C(+)CCR2(+) inflammatory monocytes, a subset of monocytes, largely orchestrate memory CD8(+) T and NK lymphocytes activation by differentiating into interleukin-18 (IL-18)- and IL-15-producing cells in an inflammasome and type I interferon-IRF3-dependent manner. Memory CD8(+) T cells became potent effector cells by sensing inflammation from monocytes independently of their cognate antigen. Like NK cells, they underwent rapid mobilization, upregulated intense and sustained effector functions during bacterial, viral, and parasitic infections, and contributed to innate responses and protection in vivo. Thus, inflammatory monocyte-derived IL-18 and IL-15 are critical to initiate memory CD8(+) T and NK lymphocytes differentiation into antimicrobial effector cells.
Subject(s)
Antigens/immunology , CD8-Positive T-Lymphocytes/immunology , Immunologic Memory/immunology , Killer Cells, Natural/immunology , Monocytes/immunology , Animals , Antigens, Ly/immunology , Antigens, Ly/metabolism , Bacterial Infections/immunology , Bacterial Infections/microbiology , CD8-Positive T-Lymphocytes/metabolism , Female , Flow Cytometry , Inflammation/immunology , Interleukin-15/genetics , Interleukin-15/immunology , Interleukin-15/metabolism , Interleukin-18/immunology , Interleukin-18/metabolism , Killer Cells, Natural/metabolism , Listeria monocytogenes/immunology , Malaria/immunology , Malaria/parasitology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Monocytes/metabolism , Plasmodium berghei/immunology , Receptors, CCR2/genetics , Receptors, CCR2/immunology , Receptors, CCR2/metabolism , Streptococcus pneumoniae/immunologyABSTRACT
Prominent changes in the gut microbiota (referred to as "dysbiosis") play a key role in the development of allergic disorders, but the underlying mechanisms remain unknown. Study of the delayed-type hypersensitivity (DTH) response in mice contributed to our knowledge of the pathophysiology of human allergic contact dermatitis. Here we report a negative regulatory role of the RIG-I-like receptor adaptor mitochondrial antiviral signaling (MAVS) on DTH by modulating gut bacterial ecology. Cohousing and fecal transplantation experiments revealed that the dysbiotic microbiota of Mavs-/- mice conferred a proallergic phenotype that is communicable to wild-type mice. DTH sensitization coincided with increased intestinal permeability and bacterial translocation within lymphoid organs that enhanced DTH severity. Collectively, we unveiled an unexpected impact of RIG-I-like signaling on the gut microbiota with consequences on allergic skin disease outcome. Primarily, these data indicate that manipulating the gut microbiota may help in the development of therapeutic strategies for the treatment of human allergic skin pathologies.
Subject(s)
Adaptor Proteins, Signal Transducing/physiology , Dysbiosis/complications , Gastrointestinal Microbiome/immunology , Hypersensitivity/etiology , Intestines/immunology , Skin Diseases, Bacterial/etiology , Animals , Disease Models, Animal , Female , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Hypersensitivity/metabolism , Hypersensitivity/pathology , Intestines/microbiology , Intestines/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , Phenotype , Signal Transduction , Skin Diseases, Bacterial/metabolism , Skin Diseases, Bacterial/pathologyABSTRACT
Invariant natural killer T (iNKT) cells have the ability to rapidly secret cytokines in response to diverse stimuli, and therefore influence numerous immune reactions. Although IFN-γ and IL-4 are thought to dominate iNKT cytokine production, a distinct subset of iNKT cells, expressing RORγt and producing IL-17, has now been identified in both mice and humans. Although a role in pathogen and allergic responses has been assigned to the RORγt(+) iNKT subset, factors controlling their development and function remain illusive. Here, we demonstrate that RORγt(+) iNKT-cell differentiation obeys transforming growth factor-ß (TGF-ß) signaling control, different from that described for conventional iNKT cells. We reveal that TGF-ß signaling, and particularly its SMAD4-dependent pathway, is required for both the survival of RORγt(+) iNKT cells during their development and IL-17 production at the periphery. Moreover, constitutive TGF-ß signaling in RORγt(+) iNKT cells drives higher peripheral numbers and increased tissue distribution. Finally, we found that SMAD4-dependent TGF-ß signaling is mandatory for the peripheral expansion of the RORγt(+) iNKT cells responding to inflammatory signals. Thus, this work demonstrates that both the development and responsiveness of the newly described IL-17-producing iNKT cell subset is under the control of a dedicated TGF-ß signaling pathway.
Subject(s)
Cell Differentiation , Natural Killer T-Cells/immunology , Natural Killer T-Cells/physiology , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , Transforming Growth Factor beta/physiology , Animals , Apoptosis/genetics , Apoptosis/physiology , Cell Differentiation/drug effects , Cell Differentiation/genetics , Cell Differentiation/immunology , Cell Proliferation/drug effects , Interleukin-17/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Natural Killer T-Cells/drug effects , Natural Killer T-Cells/metabolism , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/physiology , Receptor, Transforming Growth Factor-beta Type II , Receptors, Transforming Growth Factor beta/genetics , Receptors, Transforming Growth Factor beta/metabolism , Receptors, Transforming Growth Factor beta/physiology , Signal Transduction/genetics , Signal Transduction/immunology , Signal Transduction/physiology , Smad4 Protein/genetics , Smad4 Protein/metabolism , Thymocytes/metabolism , Thymocytes/physiology , Thymus Gland/cytology , Thymus Gland/drug effects , Thymus Gland/metabolism , Thymus Gland/physiology , Transforming Growth Factor beta/metabolism , Transforming Growth Factor beta/pharmacologyABSTRACT
We have shown previously that peripheral lymph node-resident retinoic acid receptor-related orphan receptor γt(+) NK1.1(-) invariant NKT (iNKT) cells produce IL-17A independently of IL-6. In this study, we show that the concomitant presence of IL-1 and IL-23 is crucial to induce a rapid and sustained IL-17A/F and IL-22 response by these cells that requires TCR-CD1d interaction and partly relies on IL-23-mediated upregulation of IL-23R and IL-1R1 expression. We further show that IL-1 and IL-23 produced by pathogen-associated molecular pattern-stimulated dendritic cells induce this response from NK1.1(-) iNKT cells in vitro, involving mainly TLR2/4-signaling pathways. Finally, we found that IL-17A production by these cells occurs very early and transiently in vivo in response to heat-killed bacteria. Overall, our study indicates that peripheral lymph node NK1.1(-) iNKT cells could be a source of innate Th17-related cytokines during bacterial infections and supports the hypothesis that they are able to provide an efficient first line of defense against bacterial invasion.
Subject(s)
Antigens, Ly/biosynthesis , Escherichia coli/immunology , Interleukin-17/biosynthesis , Interleukin-1beta/physiology , Interleukin-23/physiology , Lymph Nodes/immunology , NK Cell Lectin-Like Receptor Subfamily B/biosynthesis , Natural Killer T-Cells/immunology , Staphylococcus aureus/immunology , Animals , Cells, Cultured , Dendritic Cells, Follicular/immunology , Dendritic Cells, Follicular/metabolism , Immunity, Innate/genetics , Interleukin-1beta/biosynthesis , Interleukin-1beta/metabolism , Interleukin-23/biosynthesis , Interleukin-23/metabolism , Interleukins/biosynthesis , Lymph Nodes/metabolism , Lymph Nodes/microbiology , Mice , Mice, Inbred C57BL , Mice, Knockout , Natural Killer T-Cells/metabolism , Natural Killer T-Cells/microbiology , Receptors, Retinoic Acid/physiology , Signal Transduction/genetics , Signal Transduction/immunology , Interleukin-22 , Retinoic Acid Receptor gammaABSTRACT
NUPR1 (nuclear protein 1), also called P8 (molecular mass 8 kDa) or COM1 (candidate of metastasis 1), is involved in the stress response and in cancer progression. In the present study, we investigated whether human NUPR1 expression was regulated by TGFß (transforming growth factor ß), a secreted polypeptide largely involved in tumorigenesis. We demonstrate that the expression of NUPR1 was activated by TGFß at the transcriptional level. We show that this activation is mediated by the SMAD proteins, which are transcription factors specifically involved in the signalling of TGFß superfamily members. NUPR1 promoter analysis reveals the presence of a functional TGFß-response element binding the SMAD proteins located in the genomic DNA region corresponding to the 5'-UTR (5'-untranslated region). Altogether, the molecular results of the present study, which demonstrate the existence of a TGFß/SMAD/NUPR1 activation cascade, open the way to consider and investigate further a new mechanism enabling TGFß to promote tumorigenesis by inducing stress resistance.
Subject(s)
Basic Helix-Loop-Helix Transcription Factors/genetics , Gene Expression Regulation, Neoplastic , Neoplasm Proteins/genetics , Promoter Regions, Genetic/genetics , Signal Transduction , Smad Proteins/metabolism , Transcriptional Activation , Transforming Growth Factor beta/metabolism , Animals , Blotting, Western , Cells, Cultured , Chromatin Immunoprecipitation , Electrophoretic Mobility Shift Assay , Embryo, Mammalian/cytology , Embryo, Mammalian/metabolism , Fibroblasts/cytology , Fibroblasts/metabolism , Humans , Mice , Neoplasms/genetics , Neoplasms/metabolism , Neoplasms/pathology , Phosphorylation , Protein Binding , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Real-Time Polymerase Chain Reaction , Regulatory Sequences, Nucleic Acid , Reverse Transcriptase Polymerase Chain Reaction , Smad Proteins/antagonists & inhibitors , Smad Proteins/genetics , Transforming Growth Factor beta/geneticsABSTRACT
Invariant natural killer T (NKT) cell subsets are defined based on their cytokine-production profiles and transcription factors. Their distribution is different in C57BL/6 (B6) and BALB/c mice, with a bias for NKT1 and NKT2/NKT17 subsets, respectively. Here, we show that the non-classical class I-like major histocompatibility complex CD1 molecules CD1d2, expressed in BALB/c and not in B6 mice, could not account for this difference. We find however that NKT cell subset distribution is intrinsic to bone marrow derived NKT cells, regardless of syngeneic CD1d-ligand recognition, and that multiple intrinsic factors are likely involved. Finally, we find that CD1d expression levels in combination with T cell antigen receptor signal strength could also influence NKT cell distribution and function. Overall, this study indicates that CD1d-mediated TCR signals and other intrinsic signals integrate to influence strain-specific NKT cell differentiation programs and subset distributions.
Subject(s)
Natural Killer T-Cells , Animals , Mice , Antigens, CD1/metabolism , Antigens, CD1d/metabolism , Cell Differentiation , Killer Cells, Natural , Mice, Inbred C57BL , Receptors, Antigen, T-Cell/metabolism , T-Lymphocyte SubsetsABSTRACT
Inactivation of the Transforming Growth Factor Beta (TGFbeta) tumor suppressor pathway contributes to the progression of Pancreatic Ductal AdenoCarcinoma (PDAC) since it is inactivated in virtually all cases of this malignancy. Genetic lesions inactivating this pathway contribute to pancreatic tumor progression in mouse models. Transcriptional Intermediary Factor 1 gamma (TIF1gamma) has recently been proposed to be involved in TGFbeta signaling, functioning as either a positive or negative regulator of the pathway. Here, we addressed the role of TIF1gamma in pancreatic carcinogenesis. Using conditional Tif1gamma knockout mice (Tif1gamma(lox/lox)), we selectively abrogated Tif1gamma expression in the pancreas of Pdx1-Cre;Tif1gamma(lox/lox) mice. We also generated Pdx1-Cre;LSL-Kras(G12D);Tif1gamma(lox/lox) mice to address the effect of Tif1gamma loss-of-function in precancerous lesions induced by oncogenic Kras(G12D). Finally, we analyzed TIF1gamma expression in human pancreatic tumors. In our mouse model, we showed that Tif1gamma was dispensable for normal pancreatic development but cooperated with Kras activation to induce pancreatic tumors reminiscent of human Intraductal Papillary Mucinous Neoplasms (IPMNs). Interestingly, these cystic lesions resemble those observed in Pdx1-Cre;LSL-Kras(G12D);Smad4(lox/lox) mice described by others. However, distinctive characteristics, such as the systematic presence of endocrine pseudo-islets within the papillary projections, suggest that SMAD4 and TIF1gamma don't have strictly redundant functions. Finally, we report that TIF1gamma expression is markedly down-regulated in human pancreatic tumors by quantitative RT-PCR and immunohistochemistry supporting the relevance of these findings to human malignancy. This study suggests that TIF1gamma is critical for tumor suppression in the pancreas, brings new insight into the genetics of pancreatic cancer, and constitutes a promising model to decipher the respective roles of SMAD4 and TIF1gamma in the multifaceted functions of TGFbeta in carcinogenesis and development.
Subject(s)
Carcinoma, Pancreatic Ductal/metabolism , Genes, Tumor Suppressor , Pancreatic Neoplasms/metabolism , Proto-Oncogene Proteins p21(ras)/metabolism , Transcription Factors/metabolism , Animals , Carcinoma, Pancreatic Ductal/genetics , Carcinoma, Pancreatic Ductal/pathology , Humans , Mice , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Proto-Oncogene Proteins p21(ras)/genetics , Transcription Factors/geneticsABSTRACT
Bone loss associated with estrogen deficiency indicates a fundamental role of these hormones in skeletal growth and bone remodeling. In the last decades, growing recent evidence demonstrated that estrogens can also affect the immune compartment of the bone. In this review, we summarize the impacts of estrogens on bone immune cells and their consequences on bone homeostasis, metastasis settlement into the bone and tumor progression. We also addressed the role of an orphan nuclear receptor ERRalpha ("Estrogen-receptor Related Receptor alpha") on macrophages and T lymphocytes, and as an immunomodulator in bone metastases. Hence, this review links estrogens to bone immune cells in osteo-oncology.
Subject(s)
Bone Neoplasms , Estrogens , Bone Remodeling , Bone and Bones , Humans , Immunologic FactorsABSTRACT
SMAD4, a mediator of TGF-ß signaling, plays an important role in T cells to prevent inflammatory bowel disease (IBD). However, the precise mechanisms underlying this control remain elusive. Using both genetic and epigenetic approaches, we revealed an unexpected mechanism by which SMAD4 prevents naive CD8+ T cells from becoming pathogenic for the gut. Prior to the engagement of the TGF-ß receptor, SMAD4 restrains the epigenetic, transcriptional, and functional landscape of the TGF-ß signature in naive CD8+ T cells. Mechanistically, prior to TGF-ß signaling, SMAD4 binds to promoters and enhancers of several TGF-ß target genes, and by regulating histone deacetylation, suppresses their expression. Consequently, regardless of a TGF-ß signal, SMAD4 limits the expression of TGF-ß negative feedback loop genes, such as Smad7 and Ski, and likely conditions CD8+ T cells for the immunoregulatory effects of TGF-ß. In addition, SMAD4 ablation conferred naive CD8+ T cells with both a superior survival capacity, by enhancing their response to IL-7, as well as an enhanced capacity to be retained within the intestinal epithelium, by promoting the expression of Itgae, which encodes the integrin CD103. Accumulation, epithelial retention, and escape from TGF-ß control elicited chronic microbiota-driven CD8+ T cell activation in the gut. Hence, in a TGF-ß-independent manner, SMAD4 imprints a program that preconditions naive CD8+ T cell fate, preventing IBD.
Subject(s)
Graft vs Host Disease , Inflammatory Bowel Diseases , CD8-Positive T-Lymphocytes/metabolism , Humans , Inflammation , Inflammatory Bowel Diseases/genetics , Receptors, Transforming Growth Factor beta/metabolism , Smad4 Protein/genetics , Smad4 Protein/metabolism , Transforming Growth Factor beta/metabolismABSTRACT
Murine peripheral lymph node TCR γδ T cells have been divided into type 1 and type 17 functional categories based on phenotypic and functional markers. Localized in the gut epithelial barrier, intestinal intraepithelial lymphocytes (iIEL) γδ T cells constitute a peculiar subset of T lymphocytes involved in intestinal homeostasis. However, whether iIEL γδ T cells obey the type 1/type 17 dichotomy is unclear. Using both global transcriptional signatures and expression of cell surface markers, we reveal that murine iIEL γδ T cells compose a distinct population, expressing â¼1000 specific genes, in particular genes that are responsible for cytotoxicity and regulatory functions. The expression of the transcription factor Helios is a feature of iIEL γδ T cells, distinguishing them from the other TCR γδ T subsets, including those present in the epithelia of other tissues. The marked expression of Helios is also shared by the other iIELs, TCRαßCD8αα lymphocytes present within the intestinal epithelium. Finally, we show that Helios expression depends in part on TGF-ß signaling but not on the microbiota. Thus, our study proposes iIEL γδ T cells as a distinct subset and identifies novel markers to differentiate them from their peripheral counterparts.
Subject(s)
Receptors, Antigen, T-Cell, gamma-delta , T-Lymphocyte Subsets , Animals , Intestinal Mucosa/metabolism , Mice , Mice, Inbred C57BL , Receptors, Antigen, T-Cell, gamma-delta/genetics , T-Lymphocyte Subsets/metabolismABSTRACT
Transforming growth factor (TGF)-beta1 is a major pluripotential cytokine with a pronounced immunosuppressive effect and its deficiency results in lethal autoimmunity in mice. However, mechanisms of its immunosuppressive action are not completely understood. Here, we report that TGF-beta1 supports the maintenance of Foxp3 expression, regulatory function, and homeostasis in peripheral CD4(+)CD25(+) regulatory T (T reg) cells, but is not required for their thymic development. We found that in 8-10-d-old TGF-beta1-deficient mice, peripheral, but not thymic, T reg cells are significantly reduced in numbers. Moreover, our experiments suggest that a defect in TGF-beta-mediated signaling in T reg cells is associated with a decrease in Foxp3 expression and suppressor activity. Thus, our results establish an essential link between TGF-beta1 signaling in peripheral T reg cells and T reg cell maintenance in vivo.
Subject(s)
CD4-Positive T-Lymphocytes/immunology , DNA-Binding Proteins/metabolism , Immune Tolerance/immunology , Signal Transduction/immunology , Thymus Gland/immunology , Transforming Growth Factor beta/immunology , Animals , Blotting, Western , CD4-Positive T-Lymphocytes/metabolism , Cells, Cultured , Forkhead Transcription Factors , Immunosuppression Therapy , Mice , Mice, Inbred Strains , Receptors, Interleukin-2/metabolism , Transforming Growth Factor beta/metabolismABSTRACT
NF-kappaB (NF-κB) is a family of transcription factors with pleiotropic functions in immune responses. The alternative NF-κB pathway that leads to the activation of RelB and NF-κB2, was previously associated with the activation and function of T cells, though the exact contribution of these NF-κB subunits remains unclear. Here, using mice carrying conditional ablation of RelB in T cells, we evaluated its role in the development of conventional CD4+ T (Tconv) cells and their function in autoimmune diseases. RelB was largely dispensable for Tconv cell homeostasis, activation and proliferation, and for their polarization toward different flavors of Thelper cells in vitro. Moreover, ablation of RelB had no impact on the capacity of Tconv cells to induce autoimmune colitis. Conversely, clinical severity of experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS) was significantly reduced in mice with RelB-deficient T cells. This was associated with impaired expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) specifically in the central nervous system. Our data reveal a discrete role for RelB in the pathogenic function of Tconv cells during EAE, and highlight this transcription factor as a putative therapeutic target in MS.
Subject(s)
Autoimmunity , Disease Susceptibility , Encephalomyelitis, Autoimmune, Experimental/etiology , Encephalomyelitis, Autoimmune, Experimental/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Transcription Factor RelB/metabolism , Animals , Biomarkers , Colitis/etiology , Colitis/metabolism , Colitis/pathology , Disease Susceptibility/immunology , Encephalomyelitis, Autoimmune, Experimental/pathology , Homeostasis/immunology , Lymphocyte Activation , Mice , T-Lymphocytes, Helper-Inducer/immunology , T-Lymphocytes, Helper-Inducer/metabolismABSTRACT
Presence of TGFß in the tumor microenvironment is one of the most relevant cancer immune-escape mechanisms. TGFß is secreted in an inactive form, and its activation within the tumor may depend on different cell types and mechanisms than its production. Here we show in mouse melanoma and breast cancer models that regulatory T (Treg) cells expressing the ß8 chain of αvß8 integrin (Itgß8) are the main cell type in the tumors that activates TGFß, produced by the cancer cells and stored in the tumor micro-environment. Itgß8 ablation in Treg cells impairs TGFß signalling in intra-tumoral T lymphocytes but not in the tumor draining lymph nodes. Successively, the effector function of tumor infiltrating CD8+ T lymphocytes strengthens, leading to efficient control of tumor growth. In cancer patients, anti-Itgß8 antibody treatment elicits similar improved cytotoxic T cell activation. Thus, this study reveals that Treg cells work in concert with cancer cells to produce bioactive-TGFß and to create an immunosuppressive micro-environment.
Subject(s)
Integrins/immunology , Neoplasms/immunology , T-Lymphocytes, Regulatory/immunology , Transforming Growth Factor beta/immunology , Animals , Female , Humans , Integrins/genetics , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Neoplasms/genetics , Tumor MicroenvironmentABSTRACT
Suppressive regulatory T cell (Treg) differentiation is controlled by diverse immunometabolic signaling pathways and intracellular metabolites. Here we show that cell-permeable α-ketoglutarate (αKG) alters the DNA methylation profile of naive CD4 T cells activated under Treg polarizing conditions, markedly attenuating FoxP3+ Treg differentiation and increasing inflammatory cytokines. Adoptive transfer of these T cells into tumor-bearing mice results in enhanced tumor infiltration, decreased FoxP3 expression, and delayed tumor growth. Mechanistically, αKG leads to an energetic state that is reprogrammed toward a mitochondrial metabolism, with increased oxidative phosphorylation and expression of mitochondrial complex enzymes. Furthermore, carbons from ectopic αKG are directly utilized in the generation of fatty acids, associated with lipidome remodeling and increased triacylglyceride stores. Notably, inhibition of either mitochondrial complex II or DGAT2-mediated triacylglyceride synthesis restores Treg differentiation and decreases the αKG-induced inflammatory phenotype. Thus, we identify a crosstalk between αKG, mitochondrial metabolism and triacylglyceride synthesis that controls Treg fate.
Subject(s)
Cell Differentiation/drug effects , Energy Metabolism/drug effects , Ketoglutaric Acids/pharmacology , Lipid Metabolism/drug effects , Mitochondria/drug effects , T-Lymphocytes, Regulatory/drug effects , Animals , Cells, Cultured , Cytokines/genetics , Cytokines/metabolism , Diacylglycerol O-Acyltransferase/metabolism , Fibrosarcoma/genetics , Fibrosarcoma/immunology , Fibrosarcoma/metabolism , Fibrosarcoma/therapy , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Homeostasis , Humans , Immunotherapy, Adoptive , Mice, Inbred C57BL , Mice, Knockout , Mitochondria/genetics , Mitochondria/metabolism , Phenotype , Receptors, Chimeric Antigen/genetics , Receptors, Chimeric Antigen/metabolism , Signal Transduction , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/metabolism , T-Lymphocytes, Regulatory/transplantation , Th1 Cells/drug effects , Th1 Cells/immunology , Th1 Cells/metabolismABSTRACT
We have previously generated a transgenic mouse strain (LSL-TßRI(CA)) containing a Cre-inducible constitutively active TGFß type I receptor (Bartholin et al., 2008, Genesis 46: 724-731). Transgene expression depends on the excision of a floxed-transcriptional STOP (LSL, Lox-STOP-Lox) located upstream the TßRI(CA) coding sequence. To evaluate the correct excision of the STOP signal in the presence of Cre-recombinase, we developed a rapid screening based on an original PCR genotyping strategy. More precisely, we designed a set of primers flanking the LSL containing region. The size of the amplified products will differ according to recombination status of the LSL-TßRI(CA) allele. Indeed, the size of the STOP containing PCR product is 1.93 kb, but is reduced to 0.35 kb when the STOP signal is removed after Cre-mediated recombination. We validated excision in several compartments, including pancreas, liver, T lymphocytes, and embryos using different Cre expressing transgenic mouse strains. This represents a simple and efficient way of monitoring the tissue specific recombination of the LSL-TßRI(CA) allele.