RESUMEN
While IFNγ is a well-known cytokine that actively promotes the type I immune response, it is also known to suppress the type II response by inhibiting the differentiation and proliferation of Th2 cells. However, the mechanism by which IFNγ suppresses Th2 cell proliferation is still not fully understood. We found that IFNγ decreases the expression of growth factor independent-1 transcriptional repressor (GFI1) in Th2 cells, resulting in the inhibition of Th2 cell proliferation. The deletion of the Gfi1 gene in Th2 cells results in the failure of their proliferation, accompanied by an impaired cell cycle progression. In contrast, the enforced expression of GFI1 restores the defective Th2 cell proliferation, even in the presence of IFNγ. These results demonstrate that GFI1 is a key molecule in the IFNγ-mediated inhibition of Th2 cell proliferation.
Asunto(s)
Proteínas de Unión al ADN/genética , Interferón gamma/inmunología , Células Th2/citología , Factores de Transcripción/genética , Animales , Ciclo Celular , Proliferación Celular , Células Cultivadas , Regulación hacia Abajo , Eliminación de Gen , Ratones , Ratones Endogámicos C57BL , Células Th2/inmunología , Células Th2/metabolismoRESUMEN
Memory helper T (Th) cells are crucial for secondary immune responses against infectious microorganisms but also drive the pathogenesis of chronic inflammatory diseases. Therefore, it is of fundamental importance to understand how memory T cells are generated. However, the molecular mechanisms governing memory Th cell generation remain incompletely understood. Here, we identified CD30 as a molecule heterogeneously expressed on effector Th1 and Th17 cells, and CD30hi effector Th1 and Th17 cells preferentially generated memory Th1 and Th17 cells. We found that CD30 mediated signal induced Transglutaminase-2 (TG2) expression, and that the TG2 expression in effector Th cells is essential for memory Th cell generation. In fact, Cd30-deficiency resulted in the impaired generation of memory Th1 and Th17 cells, which can be rescued by overexpression of TG2. Furthermore, transglutaminase-2 (Tgm2)-deficient CD4 T cells failed to become memory Th cells. As a result, T cells from Tgm2-deficient mice displayed impaired antigen-specific antibody production and attenuated Th17-mediated allergic responses. Our data indicate that CD30-induced TG2 expression in effector Th cells is essential for the generation of memory Th1 and Th17 cells, and that CD30 can be a marker for precursors of memory Th1 and Th17 cells.
Asunto(s)
Proteínas de Unión al GTP/metabolismo , Memoria Inmunológica , Antígeno Ki-1/metabolismo , Células TH1/inmunología , Células TH1/metabolismo , Células Th17/inmunología , Células Th17/metabolismo , Transglutaminasas/metabolismo , Traslado Adoptivo , Animales , Diferenciación Celular/inmunología , Inmunofenotipificación , Ratones , Ratones Transgénicos , Proteína Glutamina Gamma Glutamiltransferasa 2 , Transducción de Señal , Células TH1/citología , Células Th17/citologíaRESUMEN
The numbers of patients with inflammatory bowel disease (IBD), such as ulcerative colitis (UC) and Crohn's disease (CD), have been increasing over time, worldwide; however, the pathogenesis of IBD is multifactorial and has not been fully understood. Myosin light chain 9 and 12a and 12b (Myl9/12) are known as ligands of the CD69 molecule. They create "Myl9 nets" that are often detected in inflamed site, which play a crucial role in regulating the recruitment and retention of CD69-expressing effector cells in inflamed tissues. We demonstrated the strong expression of Myl9/12 in the inflamed gut of IBD patients and mice with DSS-induced colitis. The administration of anti-Myl9/12 Ab to mice with DSS-induced colitis ameliorated the inflammation and prolonged their survival. The plasma Myl9 levels in the patients with active UC and CD were significantly higher than those in patients with disease remission, and may depict the disease severity of IBD patients, especially those with UC. Thus, our results indicate that Myl9/12 are involved in the pathogenesis of IBD, and are likely to be a new therapeutic target for patients suffering from IBD.
Asunto(s)
Susceptibilidad a Enfermedades , Enfermedades Inflamatorias del Intestino/etiología , Enfermedades Inflamatorias del Intestino/metabolismo , Cadenas Ligeras de Miosina/genética , Adulto , Anciano , Animales , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Biomarcadores , Estudios de Casos y Controles , Diagnóstico Diferencial , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Enfermedades Inflamatorias del Intestino/diagnóstico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Masculino , Ratones , Persona de Mediana Edad , Terapia Molecular Dirigida , Cadenas Ligeras de Miosina/antagonistas & inhibidores , Cadenas Ligeras de Miosina/metabolismoRESUMEN
CD69 is an activation marker on leukocytes. Early studies showed that the CD69+ cells were detected in the lung of patients with asthmatic and eosinophilic pneumonia, suggesting that CD69 might play crucial roles in the pathogenesis of such inflammatory diseases, rather than simply being an activation marker. Intensive studies using mouse models have since clarified that CD69 is a functional molecule regulating the immune responses. We discovered that Myosin light chain 9, 12a, 12b (Myl9/12) are ligands for CD69 and that platelet-derived Myl9 forms a net-like structure (Myl9 nets) that is strongly detected inside blood vessels in inflamed lung. CD69-expressing activated T cells attached to the Myl9 nets can thereby migrate into the inflamed tissues through a system known as the CD69-Myl9 system. In this review, we summarize the discovery of the CD69-Myl9 system and discuss how this system is important in inflammatory immune responses. In addition, we discuss our recent finding that CD69 controls the exhaustion status of tumor-infiltrating T cells and that the blockade of the CD69 function enhances anti-tumor immunity. Finally, we discuss the possibility of CD69 as a new therapeutic target for patients with intractable inflammatory disorders and tumors.
Asunto(s)
Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/metabolismo , Biomarcadores , Inmunidad , Lectinas Tipo C/metabolismo , Cadenas Ligeras de Miosina/metabolismo , Animales , Antígenos CD/química , Antígenos CD/genética , Antígenos CD/inmunología , Antígenos de Diferenciación de Linfocitos T/química , Antígenos de Diferenciación de Linfocitos T/genética , Antígenos de Diferenciación de Linfocitos T/inmunología , Transformación Celular Neoplásica , Susceptibilidad a Enfermedades , Expresión Génica , Humanos , Inflamación/etiología , Inflamación/metabolismo , Inflamación/patología , Lectinas Tipo C/química , Lectinas Tipo C/genética , Lectinas Tipo C/inmunología , Ligandos , Terapia Molecular Dirigida , Cadenas Ligeras de Miosina/química , Cadenas Ligeras de Miosina/genética , Cadenas Ligeras de Miosina/inmunología , Neoplasias/etiología , Neoplasias/metabolismo , Neoplasias/patología , Unión Proteica , Hipersensibilidad Respiratoria/etiología , Hipersensibilidad Respiratoria/metabolismo , Hipersensibilidad Respiratoria/patología , Relación Estructura-ActividadRESUMEN
BRD4 is a BET family protein that binds acetylated histones and regulates transcription. BET/BRD4 inhibitors block blood cancer growth and inflammation and serve as a new therapeutic strategy. However, the biological role of BRD4 in normal hematopoiesis and inflammation is not fully understood. Analysis of Brd4 conditional knockout (KO) mice showed that BRD4 is required for hematopoietic stem cell expansion and progenitor development. Nevertheless, BRD4 played limited roles in macrophage development and inflammatory response to LPS ChIP-seq analysis showed that despite its limited importance, BRD4 broadly occupied the macrophage genome and participated in super-enhancer (SE) formation. Although BRD4 is critical for SE formation in cancer, BRD4 was not required for macrophage SEs, as KO macrophages created alternate, BRD4-less SEs that compensated BRD4 loss. This and additional mechanisms led to the retention of inflammatory responses in macrophages. Our results illustrate a context-dependent role of BRD4 and plasticity of epigenetic regulation.
Asunto(s)
Biomarcadores/análisis , Regulación de la Expresión Génica , Células Madre Hematopoyéticas/citología , Inflamación/inmunología , Macrófagos Peritoneales/inmunología , Proteínas Nucleares/fisiología , Factores de Transcripción/fisiología , Animales , Células Cultivadas , Perfilación de la Expresión Génica , Inflamación/inducido químicamente , Inflamación/genética , Inflamación/patología , Lipopolisacáridos/toxicidad , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/metabolismo , Macrófagos Peritoneales/patología , Ratones , Ratones Endogámicos C57BL , Ratones NoqueadosRESUMEN
While CD69 may regulate thymocyte egress by inhibiting S1P1 expression, CD69 expression is not thought to be required for normal thymocyte development. Here we show that CD69 is in fact specifically required for the differentiation of mature NKT2 cells, which do not themselves express CD69. Mechanistically, CD69 expression is required on CD24+ PLZFhi innate precursors for their retention in the thymus and completion of their differentiation into mature NKT2 cells. By contrast, CD69-deficient CD24+ PLZFhi innate precursors express S1P1 and prematurely exit the thymus, while S1P1 inhibitor treatment of CD69-deficient mice retains CD24+ PLZFhi innate precursors in the thymus and restores NKT2 cell differentiation. Thus, CD69 prevents S1P1 expression on CD24+ PLZFhi innate precursor cells from aborting NKT2 differentiation in the thymus. This study reveals the importance of CD69 to prolong the thymic residency time of developing immature precursors for proper differentiation of a T cell subset.
Asunto(s)
Antígenos CD/genética , Antígenos de Diferenciación de Linfocitos T/genética , Lectinas Tipo C/genética , Linfopoyesis/genética , Células T Asesinas Naturales/citología , Receptores de Lisoesfingolípidos/genética , Subgrupos de Linfocitos T/citología , Timocitos/citología , Animales , Antígeno CD24/metabolismo , Diferenciación Celular , Regulación de la Expresión Génica , Ratones , Ratones Noqueados , Células T Asesinas Naturales/metabolismo , Proteína de la Leucemia Promielocítica con Dedos de Zinc/metabolismo , Receptores de Esfingosina-1-Fosfato , Subgrupos de Linfocitos T/metabolismo , Timocitos/metabolismoRESUMEN
GATA-binding protein 3 (GATA3) acts as the master transcription factor for type 2 T helper (Th2) cell differentiation and function. However, it is still elusive how GATA3 function is precisely regulated in Th2 cells. Here, we show that the transcription factor B cell lymphoma 11b (Bcl11b), a previously unknown component of GATA3 transcriptional complex, is involved in GATA3-mediated gene regulation. Bcl11b binds to GATA3 through protein-protein interaction, and they colocalize at many important cis-regulatory elements in Th2 cells. The expression of type 2 cytokines, including IL-4, IL-5, and IL-13, is up-regulated in Bcl11b-deficient Th2 cells both in vitro and in vivo; such up-regulation is completely GATA3 dependent. Genome-wide analyses of Bcl11b- and GATA3-regulated genes (from RNA sequencing), cobinding patterns (from chromatin immunoprecipitation sequencing), and Bcl11b-modulated epigenetic modification and gene accessibility suggest that GATA3/Bcl11b complex is involved in limiting Th2 gene expression, as well as in inhibiting non-Th2 gene expression. Thus, Bcl11b controls both GATA3-mediated gene activation and repression in Th2 cells.
Asunto(s)
Diferenciación Celular , Factor de Transcripción GATA3/metabolismo , Proteínas Represoras/metabolismo , Células TH1/citología , Células Th2/citología , Proteínas Supresoras de Tumor/metabolismo , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/metabolismo , Proliferación Celular , Cromatina/metabolismo , Citocinas/metabolismo , Epigénesis Genética , Genoma , Lectinas Tipo C/metabolismo , Ratones Endogámicos C57BL , Unión ProteicaRESUMEN
BACKGROUND: Natural killer (NK)T cells and conventional T cells share phenotypic characteristic however they differ in transcription factor requirements and functional properties. The role of histone modifying enzymes in conventional T cell development has been extensively studied, little is known about the function of enzymes regulating histone methylation in NKT cells. RESULTS: We show that conditional deletion of histone demethylases UTX and JMJD3 by CD4-Cre leads to near complete loss of liver NKT cells, while conventional T cells are less affected. Loss of NKT cells is cell intrinsic and not due to an insufficient selection environment. The absence of NKT cells in UTX/JMJD3-deficient mice protects mice from concanavalin A-induced liver injury, a model of NKT-mediated hepatitis. GO-analysis of RNA-seq data indicates that cell cycle genes are downregulated in UTX/JMJD3-deleted NKT progenitors, and suggest that failed expansion may account for some of the cellular deficiency. The phenotype appears to be demethylase-dependent, because UTY, a homolog of UTX that lacks catalytic function, is not sufficient to restore their development and removal of H3K27me3 by deletion of EZH2 partially rescues the defect. CONCLUSIONS: NKT cell development and gene expression is sensitive to proper regulation of H3K27 methylation. The H3K27me3 demethylase enzymes, in particular UTX, promote NKT cell development, and are required for effective NKT function.
RESUMEN
Thymic stromal lymphopoietin (TSLP) and IL-7 are related cytokines that mediate growth and differentiation events in the immune system. They signal through IL-7Rα-containing receptors. Target cells of TSLP in Th2 responses include CD4 T cells and dendritic cells (DCs). Although it has been reported that expression of TSLP receptor (TSLPR) on CD4 T cells is required for OVA-induced lung inflammation, DCs have also been shown to be target cells of TSLP. In this study, we show that murine ex vivo splenic DCs are unresponsive to TSLP, as they fail to phosphorylate STAT5, but in vitro overnight culture, especially in presence of IL-4, renders DCs responsive to both TSLP and IL-7. This induced responsiveness is accompanied by dramatic upregulation of IL-7Rα on DCs with little change in expression of TSLPR or of γc In splenic DCs, the induction of IL-7Rα occurs mainly in CD8- DCs. In vivo, we found that IL-4 has a differential regulatory role on expression of IL-7Rα depending on the cell type; IL-4 decreases IL-7Rα expression on CD4 T cells whereas it upregulates the expression on DCs. Our results indicate that the induction of IL-7Rα expression on DCs is critical for TSLP responsiveness and that IL-4 can upregulate IL-7Rα on DCs.
Asunto(s)
Citocinas/inmunología , Células Dendríticas/inmunología , Regulación de la Expresión Génica , Receptores de Interleucina-7/genética , Receptores de Interleucina-7/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Diferenciación Celular , Interleucina-4/genética , Interleucina-4/inmunología , Interleucina-4/farmacología , Interleucina-7/inmunología , Interleucina-7/farmacología , Ratones , Fosforilación , Factor de Transcripción STAT5/metabolismo , Transducción de Señal , Células Th2/inmunología , Regulación hacia Arriba , Linfopoyetina del Estroma TímicoRESUMEN
Epigenetic modifications, such as posttranslational modifications of histones, play an important role in gene expression and regulation. These modifications are in part mediated by the Trithorax group (TrxG) complex and the Polycomb group (PcG) complex, which activate and repress transcription, respectively. We herein investigate the role of Menin, a component of the TrxG complex in T helper (Th) cell differentiation and show a critical role for Menin in differentiation and maintenance of Th17 cells. Menin(-/-) T cells do not efficiently differentiate into Th17 cells, leaving Th1 and Th2 cell differentiation intact in in vitro cultures. Menin deficiency resulted in the attenuation of Th17-induced airway inflammation. In differentiating Th17 cells, Menin directly bound to the Il17a gene locus and was required for the deposition of permissive histone modifications and recruitment of the RNA polymerase II transcriptional complex. Interestingly, although Menin bound to the Rorc locus, Menin was dispensable for the induction of Rorc expression and permissive histone modifications in differentiating Th17 cells. In contrast, Menin was required to maintain expression of Rorc in differentiated Th17 cells, indicating that Menin is essential to stabilize expression of the Rorc gene. Thus, Menin orchestrates Th17 cell differentiation and function by regulating both the induction and maintenance of target gene expression.
Asunto(s)
Asma/inmunología , Epigénesis Genética/inmunología , Interleucina-17/inmunología , Proteínas Proto-Oncogénicas/inmunología , Células Th17/inmunología , Animales , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Cromatina/inmunología , Cromatina/metabolismo , Epigénesis Genética/genética , Regulación de la Expresión Génica/inmunología , N-Metiltransferasa de Histona-Lisina/inmunología , N-Metiltransferasa de Histona-Lisina/metabolismo , Interleucina-17/genética , Interleucina-17/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Proteína de la Leucemia Mieloide-Linfoide/inmunología , Proteína de la Leucemia Mieloide-Linfoide/metabolismo , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/genética , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/inmunología , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Ovalbúmina/inmunología , Ovalbúmina/farmacología , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , ARN Polimerasa II/inmunología , ARN Polimerasa II/metabolismo , Células Th17/metabolismoRESUMEN
Innate lymphoid cells (ILCs) are critical in innate immune responses to pathogens and lymphoid organ development. Similar to CD4(+) T helper (Th) cell subsets, ILC subsets positive for interleukin-7 receptor α (IL-7Rα) produce distinct sets of effector cytokines. However, the molecular control of IL-7Rα(+) ILC development and maintenance is unclear. Here, we report that GATA3 was indispensable for the development of all IL-7Rα(+) ILC subsets and T cells but was not required for the development of classical natural killer cells. Conditionally Gata3-deficient mice had no lymph nodes and were susceptible to Citrobactor rodentium infection. After the ILCs had fully developed, GATA3 remained important for the maintenance and functions of ILC2s. Genome-wide gene expression analyses indicated that GATA3 regulated a similar set of cytokines and receptors in Th2 cells and ILC2s, but not in ILC3s. Thus, GATA3 plays parallel roles in regulating the development and functions of CD4(+) T cells and IL-7Rα(+) ILCs.
Asunto(s)
Factor de Transcripción GATA3/metabolismo , Regulación de la Expresión Génica , Inmunidad Innata/genética , Subgrupos Linfocitarios/metabolismo , Receptores de Interleucina-7/genética , Animales , Citrobacter rodentium/inmunología , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/inmunología , Factor de Transcripción GATA3/genética , Predisposición Genética a la Enfermedad , Subgrupos Linfocitarios/inmunología , Ratones , Ratones Noqueados , Modelos Inmunológicos , Proteínas Proto-Oncogénicas c-vav/genética , Proteínas Proto-Oncogénicas c-vav/metabolismo , Receptores de Interleucina-7/metabolismoRESUMEN
T helper 17 (Th17) cells can give rise to interleukin-17A (IL-17A)- and interferon (IFN)-γ-double-producing cells that are implicated in development of autoimmune diseases. However, the molecular mechanisms that govern generation of IFN-γ-producing Th17 cells are unclear. We found that coexpression of the Th1 and Th17 cell master transcription factors, T-bet and retinoid-related orphan receptor gamma-t (RORγt), respectively, did not generate Th cells with robust IL-17 and IFN-γ expression. Instead, development of IFN-γ-producing Th17 cells required T-bet and Runx1 or Runx3. IL-12-stimulated Th17 cells upregulated Runx1, which bound to the Ifng locus in a T-bet-dependent manner. Reciprocally, T-bet or Runx1 deficiency or inhibition of Runx transcriptional activity impaired the development of IFN-γ-producing Th17 cells during experimental autoimmune encephalomyelitis, which correlated with substantially ameliorated disease course. Thus, our studies identify a critical role for T-bet and Runx transcription factors in the generation of pathogenic IFN-γ-producing Th17 cells.
Asunto(s)
Subunidades alfa del Factor de Unión al Sitio Principal/metabolismo , Interferón gamma/biosíntesis , Proteínas de Dominio T Box/metabolismo , Células Th17/inmunología , Células Th17/metabolismo , Animales , Diferenciación Celular , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Subunidad alfa 3 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 3 del Factor de Unión al Sitio Principal/metabolismo , Subunidades alfa del Factor de Unión al Sitio Principal/genética , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/metabolismo , Expresión Génica , Sitios Genéticos , Interferón gamma/genética , Ratones , Ratones Noqueados , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/genética , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Unión Proteica , Proteínas de Dominio T Box/genética , Células TH1/citología , Células TH1/inmunología , Células TH1/metabolismo , Células Th17/citologíaRESUMEN
Immunological memory is a hallmark of adaptive immunity. Memory CD4 T helper (Th) cells are central to acquired immunity, and vaccines for infectious diseases are developed based on this concept. However, memory Th cells also play a critical role in the pathogenesis of various chronic inflammatory diseases, including asthma. We refer to these populations as 'pathogenic memory Th cells.' Here, we review recent developments highlighting the functions and characteristics of several pathogenic memory type Th2 cell subsets in allergic inflammation. Also discussed are the similarities and differences between pathogenic memory Th2 cells and recently identified type 2 innate lymphoid cells (ILC2), focusing on cytokine production and phenotypic profiles.
Asunto(s)
Asma/inmunología , Células Th2/inmunología , Animales , Dermatitis/inmunología , Humanos , Inmunidad Innata , Memoria Inmunológica , Interleucina-17/biosíntesis , Interleucina-5/biosíntesis , Ratones , Modelos InmunológicosRESUMEN
GATA-binding protein 3 (Gata3) controls the differentiation of naive CD4 T cells into T helper 2 (Th2) cells by induction of chromatin remodeling of the Th2 cytokine gene loci, direct transactivation of Il5 and Il13 genes, and inhibition of Ifng. Gata3 also facilitates Th2 cell proliferation via additional mechanisms that are far less well understood. We herein found that Gata3 associates with RuvB-like protein 2 (Ruvbl2) and represses the expression of a CDK inhibitor, cyclin-dependent kinase inhibitor 2c (Cdkn2c) to facilitate the proliferation of Th2 cells. Gata3 directly bound to the Cdkn2c locus in an Ruvbl2-dependent manner. The defect in the proliferation of Gata3-deficient Th2 cells is rescued by the knockdown of Cdkn2c, indicating that Cdkn2c is a key molecule involved in the Gata3-mediated induction of Th2 cell proliferation. Ruvbl2-knockdown Th2 cells showed decreased antigen-induced expansion and caused less airway inflammation in vivo. We therefore have identified a functional Gata3/Ruvbl2 complex that regulates the proliferation of differentiating Th2 cells through the repression of a CDK inhibitor, Cdkn2c.
Asunto(s)
Proliferación Celular , Inhibidor p18 de las Quinasas Dependientes de la Ciclina/metabolismo , ADN Helicasas/inmunología , Factor de Transcripción GATA3/inmunología , Regulación de la Expresión Génica/inmunología , Complejos Multiproteicos/inmunología , Células Th2/citología , ATPasas Asociadas con Actividades Celulares Diversas , Animales , Bromodesoxiuridina , Inmunoprecipitación de Cromatina , Cartilla de ADN/genética , Técnicas de Silenciamiento del Gen , Immunoblotting , Inmunoprecipitación , Luciferasas , Espectrometría de Masas , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
BACKGROUND: IL-13 is a critical effector cytokine for allergic inflammation. It is produced by several cell types, including mast cells, basophils, and TH2 cells. In mast cells and basophils its induction can be stimulated by cross-linkage of immunoglobulin receptors or cytokines. The IL-1 family members IL-33 and IL-18 have been linked to induction of IL-13 production by mast cells and basophils. In CD4 TH2 cells IL-33-mediated production of IL-13 requires simultaneous signal transducer and activator of transcription (STAT) 5 activation. OBJECTIVE: Here we have addressed whether cytokine-induced IL-13 production in mast cells and basophils follows the same logic as in TH2 cells: requirement of 2 separate signals. METHODS: By generating a bacterial artificial chromosome (BAC) transgenic IL-13 reporter mouse, we measured IL-13 production in mast cells and basophils. RESULTS: In mast cells harvested from peritoneal cavities, 2 cytokine signals are required for IL-13 production: IL-33 and IL-3. In bone marrow mast cells IL-13 production requires IL-33, but the requirement for a STAT5 inducer is difficult to evaluate because these cells require the continuous presence of IL-3 (a STAT5 activator) for survival. Poorer STAT5 inducers in culture (IL-4 or stem cell factor) result in less IL-13 production on IL-33 challenge, but the addition of exogenous IL-3 enhances IL-13 production. This implies that bone marrow-derived mast cells, like peritoneal mast cells and TH2 cells, require stimulation both by an IL-1 family member and a STAT5 inducer to secrete IL-13. Basophils follow the same rule; splenic basophils produce IL-13 in response to IL-18 or IL-33 plus IL-3. CONCLUSION: Optimal IL-13 production from mast cells and basophils requires 2 cytokine signals.
Asunto(s)
Basófilos/inmunología , Citocinas/inmunología , Mastocitos/inmunología , Animales , Basófilos/efectos de los fármacos , Células de la Médula Ósea/citología , Células Cultivadas , Citocinas/farmacología , Proteína 1 Similar al Receptor de Interleucina-1 , Mastocitos/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Receptores de Interleucina/inmunología , Receptores de Interleucina-18/inmunología , Factor de Transcripción STAT5/inmunologíaRESUMEN
CD4(+) helper T cells are essential for immune responses and differentiate in the thymus from CD4(+) CD8(+) "double-positive" (DP) thymocytes. The transcription factor Runx3 inhibits CD4(+) T-cell differentiation by repressing Cd4 gene expression; accordingly, Runx3 is not expressed in DP thymocytes or developing CD4(+) T cells. The transcription factor Thpok is upregulated in CD4-differentiating thymocytes and required to repress Runx3. However, how Runx3 is controlled at early stages of CD4(+) T-cell differentiation, before the onset of Thpok expression, remains unknown. Here we show that Gata3, a transcription factor preferentially and transiently upregulated by CD4(+) T-cell precursors, represses Runx3 and binds the Runx3 locus in vivo. Accordingly, we show that high-level Gata3 expression and expression of Runx3 are mutually exclusive. Furthermore, whereas Runx3 represses Cd4, we show that Gata3 promotes Cd4 expression in Thpok-deficient thymocytes. Thus, in addition to its previously documented role in promoting CD4-lineage gene-expression, Gata3 represses CD8-lineage gene expression. These findings identify Gata3 as a critical pivot of CD4-CD8 lineage differentiation.
Asunto(s)
Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/inmunología , Subunidad alfa 3 del Factor de Unión al Sitio Principal/metabolismo , Factor de Transcripción GATA3/metabolismo , Timo/inmunología , Timo/metabolismo , Factores de Transcripción/metabolismo , Animales , Sitios de Unión , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Linaje de la Célula/genética , Linaje de la Célula/inmunología , Subunidad alfa 3 del Factor de Unión al Sitio Principal/genética , Regulación de la Expresión Génica , Ratones , Ratones Noqueados , Regiones Promotoras Genéticas , Factores de Transcripción/genéticaRESUMEN
T-bet is a critical transcription factor for T helper 1 (Th1) cell differentiation. To study the regulation and functions of T-bet, we developed a T-bet-ZsGreen reporter mouse strain. We determined that interleukin-12 (IL-12) and interferon-γ (IFN-γ) were redundant in inducing T-bet in mice infected with Toxoplasma gondii and that T-bet did not contribute to its own expression when induced by IL-12 and IFN-γ. By contrast, T-bet and the transcription factor Stat4 were critical for IFN-γ production whereas IFN-γ signaling was dispensable for inducing IFN-γ. Loss of T-bet resulted in activation of an endogenous program driving Th2 cell differentiation in cells expressing T-bet-ZsGreen. Genome-wide analyses indicated that T-bet directly induced many Th1 cell-related genes but indirectly suppressed Th2 cell-related genes. Our study revealed redundancy and synergy among several Th1 cell-inducing pathways in regulating the expression of T-bet and IFN-γ, and a critical role of T-bet in suppressing an endogenous Th2 cell-associated program.
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Transducción de Señal , Proteínas de Dominio T Box/inmunología , Células Th2/inmunología , Animales , Diferenciación Celular , Factor de Transcripción GATA3/inmunología , Interferón gamma/biosíntesis , Interferón gamma/inmunología , Interleucina-4/inmunología , Ratones , Ratones Noqueados , Factor de Transcripción STAT4/deficiencia , Factor de Transcripción STAT4/inmunología , Proteínas de Dominio T Box/deficiencia , Células TH1/inmunología , Células Th2/citología , Toxoplasma/inmunología , Toxoplasmosis/inmunologíaRESUMEN
Th cell effector subsets develop in response to specific cytokine environments. The development of a particular cytokine-secreting pattern requires an integration of signals that may promote the development of opposing pathways. A recent example of this paradigm is the IL-9-secreting Th9 cell that develops in response to TGF-ß and IL-4, cytokines that, in isolation, promote the development of inducible regulatory T cells and Th2 cells, respectively. To determine how the balance of these factors results in priming for IL-9 secretion, we examined the effects of each pathway on transcription factors that regulate Th cell differentiation. We demonstrated that TGF-ß induces the PU.1-encoding Sfpi1 locus and that this is independent of IL-4-induced STAT6 activation. IL-4-activated STAT6 is required for repressing the expression of T-bet and Foxp3 in Th9 cells, transcription factors that inhibit IL-9 production, and STAT6 is required for the induction of IRF4, which promotes Th9 development. These data established a transcription factor network that regulates IL-9 and demonstrated how combinations of cytokine signals generate cytokine-secreting potential by altering the expression of a panel of transcription factors.
Asunto(s)
Interleucina-9/metabolismo , Factor de Transcripción STAT6/fisiología , Linfocitos T Colaboradores-Inductores/metabolismo , Animales , Diferenciación Celular , Citocinas , Redes Reguladoras de Genes , Factores Reguladores del Interferón/genética , Interleucina-4/inmunología , Ratones , Proteínas Proto-Oncogénicas/genética , Transducción de Señal/inmunología , Linfocitos T Colaboradores-Inductores/citología , Transactivadores/genética , Activación TranscripcionalRESUMEN
Tregs not only keep immune responses to autoantigens in check, but also restrain those directed toward pathogens and the commensal microbiota. Control of peripheral immune homeostasis by Tregs relies on their capacity to accumulate at inflamed sites and appropriately adapt to their local environment. To date, the factors involved in the control of these aspects of Treg physiology remain poorly understood. Here, we show that the canonical Th2 transcription factor GATA3 is selectively expressed in Tregs residing in barrier sites including the gastrointestinal tract and the skin. GATA3 expression in both murine and human Tregs was induced upon TCR and IL-2 stimulation. Although GATA3 was not required to sustain Treg homeostasis and function at steady state, GATA3 played a cardinal role in Treg physiology during inflammation. Indeed, the intrinsic expression of GATA3 by Tregs was required for their ability to accumulate at inflamed sites and to maintain high levels of Foxp3 expression in various polarized or inflammatory settings. Furthermore, our data indicate that GATA3 limits Treg polarization toward an effector T cell phenotype and acquisition of effector cytokines in inflamed tissues. Overall, our work reveals what we believe to be a new facet in the complex role of GATA3 in T cells and highlights what may be a fundamental role in controlling Treg physiology during inflammation.
Asunto(s)
Factores de Transcripción Forkhead/inmunología , Factor de Transcripción GATA3/inmunología , Inflamación/inmunología , Inflamación/metabolismo , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Animales , Citocinas/deficiencia , Citocinas/genética , Citocinas/inmunología , Femenino , Factor de Transcripción GATA3/deficiencia , Factor de Transcripción GATA3/genética , Tracto Gastrointestinal/inmunología , Tracto Gastrointestinal/patología , Humanos , Inflamación/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Receptores de Antígenos de Linfocitos T/metabolismo , Piel/inmunología , Piel/patología , Linfocitos T Reguladores/patología , Regulación hacia ArribaRESUMEN
The transcription factor GATA3 plays an essential role during T cell development and T helper 2 (Th2) cell differentiation. To understand GATA3-mediated gene regulation, we identified genome-wide GATA3 binding sites in ten well-defined developmental and effector T lymphocyte lineages. In the thymus, GATA3 directly regulated many critical factors, including Th-POK, Notch1, and T cell receptor subunits. In the periphery, GATA3 induced a large number of Th2 cell-specific as well as Th2 cell-nonspecific genes, including several transcription factors. Our data also indicate that GATA3 regulates both active and repressive histone modifications of many target genes at their regulatory elements near GATA3 binding sites. Overall, although GATA3 binding exhibited both shared and cell-specific patterns among various T cell lineages, many genes were either positively or negatively regulated by GATA3 in a cell type-specific manner, suggesting that GATA3-mediated gene regulation depends strongly on cofactors existing in different T cells.