RESUMO
Non-alcoholic fatty liver disease (NAFLD), represents an unmet medical need that can progress to non-alcoholic steatohepatitis (NASH), which, without intervention, can result in the development of cirrhosis and hepatocellular carcinoma (HCC). Inflammation is a pathological hallmark of NASH, and targeting key inflammatory mediators of NASH may lead to potential therapeutics for the disease. Herein, we aimed to investigate the role of IL-23 signaling in NASH progression in murine models. We showed that recombinant IL-23 can promote IL-17 producing cell expansion in the liver and that these cells are predominately γδ T cells and Mucosal Associated Invariant T cells (MAITs). Reciprocally, we found that IL-23 signaling is necessary for the expansion of γδ T cells and MAIT cells in the western diet (WD) diet induced NASH model. However, we did not observe any significant differences in liver inflammation and fibrosis between wild type and Il23r-/- mice in the same NASH model. Furthermore, we found that Il23r deletion does not impact liver inflammation and fibrosis in the choline-deficient, L-amino acid-defined and high-fat diet (CDA-HFD) induced NASH model. Based on these findings, we therefore propose that IL-23 signaling is not necessary for NASH pathogenesis in preclinical models and targeting this pathway alone may not be an effective therapeutic approach to ameliorate the disease progression in NASH patients.
Assuntos
Carcinoma Hepatocelular , Hepatite , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Aminoácidos/uso terapêutico , Animais , Carcinoma Hepatocelular/patologia , Colina , Modelos Animais de Doenças , Hepatite/complicações , Mediadores da Inflamação , Interleucina-17/genética , Interleucina-23 , Cirrose Hepática/patologia , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/patologiaRESUMO
Transforming growth factor-ß (TGFß) is a key driver of fibrogenesis. Three TGFß isoforms (TGFß1, TGFß2, and TGFß3) in mammals have distinct functions in embryonic development; however, the postnatal pathological roles and activation mechanisms of TGFß2 and TGFß3 have not been well characterized. Here, we show that the latent forms of TGFß2 and TGFß3 can be activated by integrin-independent mechanisms and have lower activation thresholds compared to TGFß1. Unlike TGFB1, TGFB2 and TGFB3 expression is increased in human lung and liver fibrotic tissues compared to healthy control tissues. Thus, TGFß2 and TGFß3 may play a pathological role in fibrosis. Inducible conditional knockout mice and anti-TGFß isoform-selective antibodies demonstrated that TGFß2 and TGFß3 are independently involved in mouse fibrosis models in vivo, and selective TGFß2 and TGFß3 inhibition does not lead to the increased inflammation observed with pan-TGFß isoform inhibition. A cocrystal structure of a TGFß2-anti-TGFß2/3 antibody complex reveals an allosteric isoform-selective inhibitory mechanism. Therefore, inhibiting TGFß2 and/or TGFß3 while sparing TGFß1 may alleviate fibrosis without toxicity concerns associated with pan-TGFß blockade.
Assuntos
Fator de Crescimento Transformador beta2 , Fator de Crescimento Transformador beta3 , Animais , Modelos Animais de Doenças , Feminino , Fibrose , Humanos , Camundongos , Isoformas de Proteínas/metabolismo , Fator de Crescimento Transformador beta2/metabolismo , Fator de Crescimento Transformador beta3/metabolismoRESUMO
Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease representing a serious unmet medical need. The disease is associated with the loss of self-tolerance and exaggerated B cell activation, resulting in autoantibody production and the formation of immune complexes that accumulate in the kidney, causing glomerulonephritis. TLR7, an important mediator of the innate immune response, drives the expression of type-1 interferon (IFN), which leads to expression of type-1 IFN induced genes and aggravates lupus pathology. Because the lysosomal peptide symporter slc15a4 is critically required for type-1 interferon production by pDC, and for certain B cell functions in response to TLR7 and TLR9 signals, we considered it as a potential target for pharmacological intervention in SLE. We deleted the slc15a4 gene in C57BL/6, NZB, and NZW mice and found that pristane-challenged slc15a4-/- mice in the C57BL/6 background and lupus prone slc15a4-/- NZB/W F1 mice were both completely protected from lupus like disease. In the NZB/W F1 model, protection persisted even when disease development was accelerated with an adenovirus encoding IFNα, emphasizing a broad role of slc15a4 in disease initiation. Our results establish a non-redundant function of slc15a4 in regulating both innate and adaptive components of the immune response in SLE pathobiology and suggest that it may be an attractive drug target.
Assuntos
Lúpus Eritematoso Sistêmico/patologia , Proteínas de Membrana Transportadoras/metabolismo , Animais , Quimiocinas/metabolismo , Citocinas/metabolismo , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Imidazóis/farmacologia , Interferon-alfa/genética , Interferon-alfa/metabolismo , Interferon-alfa/farmacologia , Lúpus Eritematoso Sistêmico/metabolismo , Lúpus Eritematoso Sistêmico/mortalidade , Proteínas de Membrana Transportadoras/deficiência , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NZB , Camundongos Knockout , Taxa de Sobrevida , Terpenos/farmacologia , Receptor 7 Toll-Like/agonistas , Receptor 7 Toll-Like/metabolismo , Receptor Toll-Like 9/metabolismoRESUMO
The cytokine interleukin-22 (IL-22) is a critical regulator of epithelial homeostasis. It has been implicated in multiple aspects of epithelial barrier function, including regulation of epithelial cell growth and permeability, production of mucus and antimicrobial proteins (AMPs), and complement production. In this review, we focus specifically on the role of IL-22 in the intestinal epithelium. We summarize recent advances in our understanding of how IL-22 regulates homeostasis and host defense, and we discuss the IL-22 pathway as a therapeutic target in diseases of the intestine, including inflammatory bowel disease (IBD), graft-versus-host disease (GVHD), and cancer.
Assuntos
Interleucinas/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/patologia , Animais , Células Epiteliais/metabolismo , Doença Enxerto-Hospedeiro/metabolismo , Humanos , Doenças Inflamatórias Intestinais/metabolismo , Interleucina 22RESUMO
The dysregulation of multiple signaling pathways, including those through endosomal Toll-like receptors (TLRs), Fc gamma receptors (FcγR), and antigen receptors in B cells (BCR), promote an autoinflammatory loop in systemic lupus erythematosus (SLE). Here, we used selective small-molecule inhibitors to assess the regulatory roles of interleukin-1 receptor (IL-1R)-associated kinase 4 (IRAK4) and Bruton's tyrosine kinase (BTK) in these pathways. The inhibition of IRAK4 repressed SLE immune complex- and TLR7-mediated activation of human plasmacytoid dendritic cells (pDCs). Correspondingly, the expression of interferon (IFN)-responsive genes (IRGs) in cells and in mice was positively regulated by the kinase activity of IRAK4. Both IRAK4 and BTK inhibition reduced the TLR7-mediated differentiation of human memory B cells into plasmablasts. TLR7-dependent inflammatory responses were differentially regulated by IRAK4 and BTK by cell type: In pDCs, IRAK4 positively regulated NF-κB and MAPK signaling, whereas in B cells, NF-κB and MAPK pathways were regulated by both BTK and IRAK4. In the pristane-induced lupus mouse model, inhibition of IRAK4 reduced the expression of IRGs during disease onset. Mice engineered to express kinase-deficient IRAK4 were protected from both chemical (pristane-induced) and genetic (NZB/W_F1 hybrid) models of lupus development. Our findings suggest that kinase inhibitors of IRAK4 might be a therapeutic in patients with SLE.
Assuntos
Células Dendríticas/metabolismo , Endossomos/metabolismo , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Glicoproteínas de Membrana/metabolismo , Plasmócitos/metabolismo , Transdução de Sinais , Receptor 7 Toll-Like/metabolismo , Tirosina Quinase da Agamaglobulinemia , Animais , Endossomos/genética , Humanos , Quinases Associadas a Receptores de Interleucina-1/genética , Glicoproteínas de Membrana/genética , Camundongos , Receptor 7 Toll-Like/genéticaRESUMO
Since the birth of biotechnology, hundreds of biotherapeutics have been developed and approved by the US Food and Drug Administration (FDA) for human use. These novel medicines not only bring significant benefit to patients but also represent precision tools to interrogate human disease biology. Accordingly, much has been learned from the successes and failures of hundreds of high-quality clinical trials. In this review, we discuss general and broadly applicable themes that have emerged from this collective experience. We base our discussion on insights gained from exploring some of the most important target classes, including interleukin-1 (IL-1), tumor necrosis factor α (TNF-α), IL-6, IL-12/23, IL-17, IL-4/13, IL-5, immunoglobulin E (IgE), integrins and B cells. We also describe current challenges and speculate about how emerging technological capabilities may enable the discovery and development of the next generation of biotherapeutics.
Assuntos
Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Terapia Biológica , Desenvolvimento de Medicamentos , Animais , Produtos Biológicos/história , Terapia Biológica/história , Terapia Biológica/métodos , Biotecnologia/história , Biotecnologia/métodos , Ensaios Clínicos como Assunto , Desenvolvimento de Medicamentos/história , Descoberta de Drogas/história , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos , História do Século XX , História do Século XXI , HumanosRESUMO
Disruption of interleukin-13 (IL-13) signaling with large molecule antibody therapies has shown promise in diseases of allergic inflammation. Given that IL-13 recruits several members of the Janus Kinase family (JAK1, JAK2, and TYK2) to its receptor complex, JAK inhibition may offer an alternate small molecule approach to disrupting IL-13 signaling. Herein we demonstrate that JAK1 is likely the isoform most important to IL-13 signaling. Structure-based design was then used to improve the JAK1 potency of a series of previously reported JAK2 inhibitors. The ability to impede IL-13 signaling was thereby significantly improved, with the best compounds exhibiting single digit nM IC50's in cell-based assays dependent upon IL-13 signaling. Appropriate substitution was further found to influence inhibition of a key off-target, LRRK2. Finally, the most potent compounds were found to be metabolically labile, which makes them ideal scaffolds for further development as topical agents for IL-13 mediated diseases of the lungs and skin (for example asthma and atopic dermatitis, respectively).
Assuntos
Dermatite Atópica/genética , Interleucina-13/metabolismo , Janus Quinase 1/antagonistas & inibidores , Janus Quinase 2/antagonistas & inibidores , Humanos , Transdução de SinaisRESUMO
Preclinical and clinical evidence indicates that a subset of asthma is driven by type 2 cytokines such as interleukin-4 (IL-4), IL-5, IL-9, and IL-13. Additional evidence predicts pathogenic roles for IL-6 and type I and type II interferons. Because each of these cytokines depends on Janus kinase 1 (JAK1) for signal transduction, and because many of the asthma-related effects of these cytokines manifest in the lung, we hypothesized that lung-restricted JAK1 inhibition may confer therapeutic benefit. To test this idea, we synthesized iJak-381, an inhalable small molecule specifically designed for local JAK1 inhibition in the lung. In pharmacodynamic models, iJak-381 suppressed signal transducer and activator of transcription 6 activation by IL-13. Furthermore, iJak-381 suppressed ovalbumin-induced lung inflammation in both murine and guinea pig asthma models and improved allergen-induced airway hyperresponsiveness in mice. In a model driven by human allergens, iJak-381 had a more potent suppressive effect on neutrophil-driven inflammation compared to systemic corticosteroid administration. The inhibitor iJak-381 reduced lung pathology, without affecting systemic Jak1 activity in rodents. Our data show that local inhibition of Jak1 in the lung can suppress lung inflammation without systemic Jak inhibition in rodents, suggesting that this strategy might be effective for treating asthma.
Assuntos
Asma/tratamento farmacológico , Asma/enzimologia , Janus Quinase 1/antagonistas & inibidores , Pulmão/enzimologia , Inibidores de Proteínas Quinases/uso terapêutico , Administração por Inalação , Alérgenos , Animais , Asma/patologia , Dexametasona/farmacologia , Dexametasona/uso terapêutico , Modelos Animais de Doenças , Eosinófilos/efeitos dos fármacos , Eosinófilos/metabolismo , Eosinófilos/patologia , Cobaias , Inflamação/patologia , Janus Quinase 1/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/patologia , Ovalbumina , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Transdução de Sinais , Resultado do TratamentoRESUMO
NF-κB-inducing kinase (NIK) is a protein kinase central to the noncanonical NF-κB pathway downstream from multiple TNF receptor family members, including BAFF, which has been associated with B cell survival and maturation, dendritic cell activation, secondary lymphoid organ development, and bone metabolism. We report herein the discovery of lead chemical series of NIK inhibitors that were identified through a scaffold-hopping strategy using structure-based design. Electronic and steric properties of lead compounds were modified to address glutathione conjugation and amide hydrolysis. These highly potent compounds exhibited selective inhibition of LTßR-dependent p52 translocation and transcription of NF-κB2 related genes. Compound 4f is shown to have a favorable pharmacokinetic profile across species and to inhibit BAFF-induced B cell survival in vitro and reduce splenic marginal zone B cells in vivo.
Assuntos
Descoberta de Drogas , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Camundongos , Modelos Moleculares , Conformação Proteica , Proteínas Serina-Treonina Quinases/química , Quinase Induzida por NF-kappaBRESUMO
Bruton's tyrosine kinase (Btk) is a nonreceptor cytoplasmic tyrosine kinase involved in B-cell and myeloid cell activation, downstream of B-cell and Fcγ receptors, respectively. Preclinical studies have indicated that inhibition of Btk activity might offer a potential therapy in autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. Here we disclose the discovery and preclinical characterization of a potent, selective, and noncovalent Btk inhibitor currently in clinical development. GDC-0853 (29) suppresses B cell- and myeloid cell-mediated components of disease and demonstrates dose-dependent activity in an in vivo rat model of inflammatory arthritis. It demonstrates highly favorable safety, pharmacokinetic (PK), and pharmacodynamic (PD) profiles in preclinical and Phase 2 studies ongoing in patients with rheumatoid arthritis, lupus, and chronic spontaneous urticaria. On the basis of its potency, selectivity, long target residence time, and noncovalent mode of inhibition, 29 has the potential to be a best-in-class Btk inhibitor for a wide range of immunological indications.
Assuntos
Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Anti-Inflamatórios/farmacologia , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridonas/farmacologia , Tirosina Quinase da Agamaglobulinemia/efeitos dos fármacos , Tirosina Quinase da Agamaglobulinemia/genética , Animais , Anti-Inflamatórios/farmacocinética , Anti-Inflamatórios/toxicidade , Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Cães , Descoberta de Drogas , Humanos , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Células Madin Darby de Rim Canino , Modelos Moleculares , Estrutura Molecular , Piperazinas/farmacocinética , Piperazinas/toxicidade , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/toxicidade , Piridonas/farmacocinética , Piridonas/toxicidade , Ratos , Ratos Endogâmicos Lew , Ratos Sprague-DawleyRESUMO
NF-κB-inducing kinase (NIK) mediates non-canonical NF-κB signaling downstream of multiple TNF family members, including BAFF, TWEAK, CD40, and OX40, which are implicated in the pathogenesis of systemic lupus erythematosus (SLE). Here, we show that experimental lupus in NZB/W F1 mice can be treated with a highly selective and potent NIK small molecule inhibitor. Both in vitro as well as in vivo, NIK inhibition recapitulates the pharmacological effects of BAFF blockade, which is clinically efficacious in SLE. Furthermore, NIK inhibition also affects T cell parameters in the spleen and proinflammatory gene expression in the kidney, which may be attributable to inhibition of OX40 and TWEAK signaling, respectively. As a consequence, NIK inhibition results in improved survival, reduced renal pathology, and lower proteinuria scores. Collectively, our data suggest that NIK inhibition is a potential therapeutic approach for SLE.
Assuntos
Linfócitos B/efeitos dos fármacos , Rim/efeitos dos fármacos , Lúpus Eritematoso Sistêmico/imunologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Linfócitos T/efeitos dos fármacos , Animais , Linfócitos B/imunologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocina TWEAK/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Modelos Animais de Doenças , Expressão Gênica/efeitos dos fármacos , Humanos , Técnicas In Vitro , Inflamação/genética , Subunidade p40 da Interleucina-12/efeitos dos fármacos , Subunidade p40 da Interleucina-12/imunologia , Rim/imunologia , Rim/patologia , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Nefrite Lúpica/imunologia , Nefrite Lúpica/patologia , Camundongos , Camundongos Endogâmicos NZB , Terapia de Alvo Molecular , Proteinúria/imunologia , Receptores OX40/metabolismo , Transdução de Sinais , Baço/efeitos dos fármacos , Baço/imunologia , Linfócitos T/imunologia , Quinase Induzida por NF-kappaBRESUMO
Herein we report identification of an imidazopyridine class of potent and selective TYK2 inhibitors, exemplified by prototype 6, through constraint of the rotatable amide bond connecting the pyridine and aryl rings of compound 1. Further optimization led to generation of compound 30 that potently inhibits the TYK2 enzyme and the IL-23 pathway in cells, exhibits selectivity against cellular JAK2 activity, and has good pharmacokinetic properties. In mice, compound 30 demonstrated dose-dependent reduction of IL-17 production in a PK/PD model as well as in an imiquimod-induced psoriasis model. In this efficacy model, the IL-17 decrease was accompanied by a reduction of ear thickness indicating the potential of TYK2 inhibition as a therapeutic approach for psoriasis patients.
Assuntos
Imidazóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , TYK2 Quinase/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Imidazóis/síntese química , Imidazóis/química , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Piridinas/síntese química , Piridinas/química , Relação Estrutura-Atividade , TYK2 Quinase/metabolismoRESUMO
Tuberculosis (TB), caused by Mycobacterium tuberculosis infection, is a leading cause of mortality and morbidity, causing â¼1.5 million deaths annually. CD4+ T cells and several cytokines, such as the Th1 cytokine IFN-γ, are critical in the control of this infection. Conversely, the immunosuppressive cytokine IL-10 has been shown to dampen Th1 cell responses to M. tuberculosis infection impairing bacterial clearance. However, the critical cellular source of IL-10 during M. tuberculosis infection is still unknown. Using IL-10 reporter mice, we show in this article that during the first 14 d of M. tuberculosis infection, the predominant cells expressing IL-10 in the lung were Ly6C+ monocytes. However, after day 21 postinfection, IL-10-expressing T cells were also highly represented. Notably, mice deficient in T cell-derived IL-10, but not mice deficient in monocyte-derived IL-10, showed a significant reduction in lung bacterial loads during chronic M. tuberculosis infection compared with fully IL-10-competent mice, indicating a major role for T cell-derived IL-10 in TB susceptibility. IL-10-expressing cells were detected among both CD4+ and CD8+ T cells, expressed high levels of CD44 and Tbet, and were able to coproduce IFN-γ and IL-10 upon ex vivo stimulation. Furthermore, during M. tuberculosis infection, Il10 expression in CD4+ T cells was partially regulated by both IL-27 and type I IFN signaling. Together, our data reveal that, despite the multiple immune sources of IL-10 during M. tuberculosis infection, activated effector T cells are the major source accounting for IL-10-induced TB susceptibility.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Interleucina-10/imunologia , Tuberculose/imunologia , Animais , Antígenos Ly/imunologia , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/imunologia , Interferon Tipo I/imunologia , Interferon Tipo I/metabolismo , Interferon gama/biossíntese , Interferon gama/imunologia , Interleucina-10/biossíntese , Interleucina-10/deficiência , Interleucina-10/genética , Interleucinas/imunologia , Interleucinas/metabolismo , Camundongos , Monócitos/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose/microbiologiaRESUMO
Germinal centers (GC) give rise to high-affinity and long-lived Abs and are critical in immunity and autoimmunity. IL-27 supports GCs by promoting survival and function of T follicular helper cells. We demonstrate that IL-27 also directly enhances GC B cell function. Exposure of naive human B cells to rIL-27 during in vitro activation enhanced their differentiation into CD20+CD38+CD27lowCD95+CD10+ cells, consistent with the surface marker phenotype of GC B cells. This effect was inhibited by loss-of-function mutations in STAT1 but not STAT3 To extend these findings, we studied the in vivo effects of IL-27 signals to B cells in the GC-driven Roquinsan/san lupus mouse model. Il27ra-/-Roquinsan/san mice exhibited significantly reduced GCs, IgG2a(c)+ autoantibodies, and nephritis. Mixed bone marrow chimeras confirmed that IL-27 acts through B cell- and CD4+ T cell-intrinsic mechanisms to support GCs and alter the production of pathogenic Ig isotypes. To our knowledge, our data provide the first evidence that IL-27 signals directly to B cells promote GCs and support the role of IL-27 in lupus.
Assuntos
Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Centro Germinativo/imunologia , Interleucina-27/metabolismo , Nefrite Lúpica/imunologia , Animais , Diferenciação Celular , Células Cultivadas , Modelos Animais de Doenças , Humanos , Interleucina-27/imunologia , Nefrite Lúpica/genética , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Citocinas/genética , Receptores de Interleucina , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT3/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
Reestablishment of competent regulatory pathways has emerged as a strategy to reduce the severity of graft-versus-host disease (GVHD), and recalibrate the effector and regulatory arms of the immune system. However, clinically feasible, cost-effective strategies that do not require extensive ex vivo cellular manipulation have remained elusive. In the current study, we demonstrate that inhibition of the interleukin-27p28 (IL-27p28) signaling pathway through antibody blockade or genetic ablation prevented lethal GVHD in multiple murine transplant models. Moreover, protection from GVHD was attributable to augmented global reconstitution of CD4+ natural regulatory T cells (nTregs), CD4+ induced Tregs (iTregs), and CD8+ iTregs, and was more potent than temporally concordant blockade of IL-6 signaling. Inhibition of IL-27p28 also enhanced the suppressive capacity of adoptively transferred CD4+ nTregs by increasing the stability of Foxp3 expression. Notably, blockade of IL-27p28 signaling reduced T-cell-derived-IL-10 production in conventional T cells; however, there was no corresponding effect in CD4+ or CD8+ Tregs, indicating that IL-27 inhibition had differential effects on IL-10 production and preserved a mechanistic pathway by which Tregs are known to suppress GVHD. Targeting of IL-27 therefore represents a novel strategy for the in vivo expansion of Tregs and subsequent prevention of GVHD without the requirement for ex vivo cellular manipulation, and provides additional support for the critical proinflammatory role that members of the IL-6 and IL-12 cytokine families play in GVHD biology.
Assuntos
Fatores de Transcrição Forkhead/imunologia , Regulação da Expressão Gênica/imunologia , Doença Enxerto-Hospedeiro/prevenção & controle , Interleucinas/antagonistas & inibidores , Transdução de Sinais/imunologia , Linfócitos T Reguladores/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/genética , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/patologia , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-12/genética , Interleucina-12/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Interleucinas/genética , Interleucinas/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Transdução de Sinais/genética , Linfócitos T Reguladores/patologiaRESUMO
Bromo and extra terminal (BET) proteins (BRD2, BRD3, BRD4 and BRDT) are epigenetic transcriptional regulators required for efficient expression of growth promoting, cell cycle progression and antiapoptotic genes. Through their bromodomain, these proteins bind to acetylated lysine residues of histones and are recruited to transcriptionally active chromatin. Inhibition of the BET-histone interaction provides a tractable therapeutic strategy to treat diseases that may have epigenetic dysregulation. JQ1 is a small molecule that blocks BET interaction with histones. It has been shown to decrease proliferation of patient-derived multiple myeloma in vitro and to decrease tumor burden in vivo in xenograft mouse models. While targeting BET appears to be a viable and efficacious approach, the nonclinical safety profile of BET inhibition remains to be well-defined. We report that mice dosed with JQ1 at efficacious exposures demonstrate dose-dependent decreases in their lymphoid and immune cell compartments. At higher doses, JQ1 was not tolerated and due to induction of significant body weight loss led to early euthanasia. Flow cytometry analysis of lymphoid tissues showed a decrease in both B- and T-lymphocytes with a concomitant decrease in peripheral white blood cells that was confirmed by hematology. Further investigation with the inactive enantiomer of JQ1 showed that these in vivo effects were on-target mediated and not elicited through secondary pharmacology due to chemical structure.
Assuntos
Azepinas/farmacologia , Sistema Imunitário/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Triazóis/farmacologia , Animais , Azepinas/administração & dosagem , Relação Dose-Resposta a Droga , Epigenômica , Sistema Imunitário/patologia , Linfócitos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Reticulócitos/efeitos dos fármacos , Triazóis/administração & dosagemRESUMO
Interleukin-2 (IL-2)-inducible T cell kinase (ITK) mediates T cell receptor (TCR) signaling primarily to stimulate the production of cytokines, such as IL-4, IL-5, and IL-13, from T helper 2 (TH2) cells. Compared to wild-type mice, ITK knockout mice are resistant to asthma and exhibit reduced lung inflammation and decreased amounts of TH2-type cytokines in the bronchoalveolar lavage fluid. We found that a small-molecule selective inhibitor of ITK blocked TCR-mediated signaling in cultured TH2 cells, including the tyrosine phosphorylation of phospholipase C-γ1 (PLC-γ1) and the secretion of IL-2 and TH2-type cytokines. Unexpectedly, inhibition of the kinase activity of ITK during or after antigen rechallenge in an ovalbumin-induced mouse model of asthma failed to reduce airway hyperresponsiveness and inflammation. Rather, in mice, pharmacological inhibition of ITK resulted in T cell hyperplasia and the increased production of TH2-type cytokines. Thus, our studies predict that inhibition of the kinase activity of ITK may not be therapeutic in patients with asthma.
Assuntos
Asma/imunologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Células Th2/imunologia , Animais , Asma/genética , Asma/patologia , Morte Celular/efeitos dos fármacos , Citocinas/genética , Citocinas/imunologia , Modelos Animais de Doenças , Feminino , Humanos , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Fosfolipase C gama/genética , Fosfolipase C gama/imunologia , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/imunologia , Células Th2/patologiaRESUMO
CD4+ T cells mediate protection against Mycobacterium tuberculosis (Mtb); however, the phenotype of protective T cells is undefined, thereby confounding vaccination efforts. IL-27 is highly expressed during human tuberculosis (TB), and absence of IL-27R (Il27ra) specifically on T cells results in increased protection. IL-27R deficiency during chronic Mtb infection does not impact antigen-specific CD4+ T cell number but maintains programmed death-1 (PD-1), CD69, and CD127 expression while reducing T-bet and killer cell lectin-like receptor G1 (KLRG1) expression. Furthermore, T-bet haploinsufficiency results in failure to generate KLRG1+, antigen-specific CD4+ T cells, and in improved protection. T cells in Il27ra(-/-) mice accumulate preferentially in the lung parenchyma within close proximity to Mtb, and antigen-specific CD4+ T cells lacking IL-27R are intrinsically more fit than intact T cells and maintain IL-2 production. Improved fitness of IL-27R-deficient T cells is not associated with increased proliferation but with decreased expression of cell death-associated markers. Therefore, during Mtb infection, IL-27R acts intrinsically on T cells to limit protection and reduce fitness, whereas the IL-27R-deficient environment alters the phenotype and location of T cells. The significant expression of IL-27 in TB and the negative influence of IL-27R on T cell function demonstrate the pathway by which this cytokine/receptor pair is detrimental in TB.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Mycobacterium tuberculosis/imunologia , Receptores de Citocinas/imunologia , Receptores de Interleucina/imunologia , Tuberculose/imunologia , Adulto , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos T/genética , Antígenos de Diferenciação de Linfócitos T/imunologia , Linfócitos T CD4-Positivos/patologia , Feminino , Humanos , Subunidade alfa de Receptor de Interleucina-7/genética , Subunidade alfa de Receptor de Interleucina-7/imunologia , Interleucinas/genética , Interleucinas/imunologia , Lectinas Tipo C/genética , Lectinas Tipo C/imunologia , Masculino , Camundongos , Camundongos Knockout , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/imunologia , Receptores de Citocinas/genética , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia , Receptores de Interleucina/genética , Transativadores/genética , Transativadores/imunologia , Tuberculose/genética , Tuberculose/patologiaRESUMO
Mammalian hosts are colonized with commensal microbes in various mucosal and epithelial tissues, including the intestinal tract. In mice, the presence of segmented filamentous bacteria (SFB) promotes Th17 differentiation and the development of autoimmune disease. Here, we demonstrate that the IL-23 pathway dynamically regulates the abundance of SFB as well as mucosal barrier function in the adult animal. Genetic or pharmacological inactivation of the pathway selectively perturbs the abundance of a small group of commensals, including SFB, and results in an impaired mucosal barrier. Defective barrier function leads to systemic dissemination of microbial products, provoking induction of the IL-23 pathway with dual consequences: IL-23 drives IL-22 production to reinforce mucosal barrier function and elicit antimicrobial activities, and it also drives the differentiation of Th17 cells in an attempt to combat escaped microbes in the lamina propria and in distal tissues. Thus, barrier defects generate a systemic environment that facilitates Th17 development.
Assuntos
Interleucinas/imunologia , Mucosa Intestinal/imunologia , Microbiota/imunologia , Receptores de Interleucina/imunologia , Células Th17/imunologia , Animais , Diferenciação Celular/imunologia , Interleucinas/genética , Mucosa Intestinal/microbiologia , Camundongos , Camundongos Knockout , Receptores de Interleucina/genética , Interleucina 22RESUMO
Tuberculosis, caused by the intracellular bacterium Mycobacterium tuberculosis, currently causes â¼1.4 million deaths per year, and it therefore remains a leading global health problem. The immune response during tuberculosis remains incompletely understood, particularly regarding immune factors that are harmful rather than protective to the host. Overproduction of the type I IFN family of cytokines is associated with exacerbated tuberculosis in both mouse models and in humans, although the mechanisms by which type I IFN promotes disease are not well understood. We have investigated the effect of type I IFN on M. tuberculosis-infected macrophages and found that production of host-protective cytokines such as TNF-α, IL-12, and IL-1ß is inhibited by exogenous type I IFN, whereas production of immunosuppressive IL-10 is promoted in an IL-27-independent manner. Furthermore, much of the ability of type I IFN to inhibit cytokine production was mediated by IL-10. Additionally, type I IFN compromised macrophage activation by the lymphoid immune response through severely disrupting responsiveness to IFN-γ, including M. tuberculosis killing. These findings describe important mechanisms by which type I IFN inhibits the immune response during tuberculosis.