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1.
Artigo em Inglês | MEDLINE | ID: mdl-39292604

RESUMO

OBJECTIVES: Gut and joint disease commonly co-occur in spondyloarthritis (SpA). Up to 50% of SpA-patients show signs of subclinical gut inflammation and 10% evolves into inflammatory bowel disease (IBD). However, the mechanisms underlying this gut-joint axis are still unclear. Here we tested the hypothesis whether restricted expression of a pro-inflammatory cytokine in the intestine may trigger onset of combined gut and joint inflammation. METHODS: Intestinal expression of human TNF (hTNF) was achieved by driving hTNF gene expression under control of the rat FAPB2 promoter, creating a new animal model, the TNFgut mice, which expresses hTNF in the proximal intestinal tract. Intestinal-specific TNFgut mice were examined for pathological changes in the intestine and extra-intestinal tissues by means of histology, qPCR and flow cytometry, along with 16S sequencing on stools. RESULTS: Local expression of hTNF in the epithelium of the small intestine induces a pro-inflammatory state of the proximal intestinal tract with epithelial alterations and induction of members of the S100 family, as well as local upregulation of T helper 17 and regulatory T cells, but no obvious signs of dysbiosis. Curiously, TNFgut mice develop sacroiliitis (p< 0.05) in addition to small bowel inflammation (p< 0.05). However, no signs of peripheral arthritis nor enthesitis could be documented. CONCLUSION: Intestinal expression of hTNF is sufficient to initiate a pro-inflammatory cascade culminating in small bowel inflammation and sacroiliitis. Thus, gut-derived cytokines are sufficient to induce spondyloarthritis.

2.
EMBO Rep ; 21(6): e48927, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32363653

RESUMO

CD1d-restricted invariant natural killer T (iNKT) cells constitute a common glycolipid-reactive innate-like T-cell subset with a broad impact on innate and adaptive immunity. While several microbial glycolipids are known to activate iNKT cells, the cellular mechanisms leading to endogenous CD1d-dependent glycolipid responses remain largely unclear. Here, we show that endoplasmic reticulum (ER) stress in APCs is a potent inducer of CD1d-dependent iNKT cell autoreactivity. This pathway relies on the presence of two transducers of the unfolded protein response: inositol-requiring enzyme-1a (IRE1α) and protein kinase R-like ER kinase (PERK). Surprisingly, the neutral but not the polar lipids generated within APCs undergoing ER stress are capable of activating iNKT cells. These data reveal that ER stress is an important mechanism to elicit endogenous CD1d-restricted iNKT cell responses through induction of distinct classes of neutral lipids.


Assuntos
Células T Matadoras Naturais , Células Apresentadoras de Antígenos , Antígenos CD1d/genética , Endorribonucleases , Lipídeos , Ativação Linfocitária , Proteínas Serina-Treonina Quinases
3.
Nature ; 512(7512): 69-73, 2014 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-25043000

RESUMO

Rheumatoid arthritis is a chronic autoinflammatory disease that affects 1-2% of the world's population and is characterized by widespread joint inflammation. Interleukin-1 is an important mediator of cartilage destruction in rheumatic diseases, but our understanding of the upstream mechanisms leading to production of interleukin-1ß in rheumatoid arthritis is limited by the absence of suitable mouse models of the disease in which inflammasomes contribute to pathology. Myeloid-cell-specific deletion of the rheumatoid arthritis susceptibility gene A20/Tnfaip3 in mice (A20(myel-KO) mice) triggers a spontaneous erosive polyarthritis that resembles rheumatoid arthritis in patients. Rheumatoid arthritis in A20(myel-KO) mice is not rescued by deletion of tumour necrosis factor receptor 1 (ref. 2). Here we show, however, that it crucially relies on the Nlrp3 inflammasome and interleukin-1 receptor signalling. Macrophages lacking A20 have increased basal and lipopolysaccharide-induced expression levels of the inflammasome adaptor Nlrp3 and proIL-1ß. As a result, A20-deficiency in macrophages significantly enhances Nlrp3 inflammasome-mediated caspase-1 activation, pyroptosis and interleukin-1ß secretion by soluble and crystalline Nlrp3 stimuli. In contrast, activation of the Nlrc4 and AIM2 inflammasomes is not altered. Importantly, increased Nlrp3 inflammasome activation contributes to the pathology of rheumatoid arthritis in vivo, because deletion of Nlrp3, caspase-1 and the interleukin-1 receptor markedly protects against rheumatoid-arthritis-associated inflammation and cartilage destruction in A20(myel-KO) mice. These results reveal A20 as a novel negative regulator of Nlrp3 inflammasome activation, and describe A20(myel-KO) mice as the first experimental model to study the role of inflammasomes in the pathology of rheumatoid arthritis.


Assuntos
Artrite Reumatoide/metabolismo , Proteínas de Transporte/metabolismo , Cisteína Endopeptidases/metabolismo , Inflamassomos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Artrite Reumatoide/imunologia , Artrite Reumatoide/patologia , Artrite Reumatoide/prevenção & controle , Proteínas de Ligação ao Cálcio/metabolismo , Caspase 1/deficiência , Caspase 1/metabolismo , Cisteína Endopeptidases/deficiência , Proteínas de Ligação a DNA , Modelos Animais de Doenças , Feminino , Interleucina-1/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR , Proteínas Nucleares/metabolismo , Fenótipo , Receptores de Interleucina-1/deficiência , Receptores de Interleucina-1/metabolismo , Transdução de Sinais , Proteína 3 Induzida por Fator de Necrose Tumoral alfa
4.
Ann Rheum Dis ; 76(3): 585-592, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27551052

RESUMO

OBJECTIVES: A20 is an important endogenous regulator of inflammation. Single nucleotide polymorphisms in A20 have been associated with various immune-mediated inflammatory diseases, and cell-specific deletion of A20 results in diverse inflammatory phenotypes. Our goal was to delineate the underlying mechanisms of joint inflammation in myeloid-specific A20-deficient mice (A20myelKO mice). METHODS: Inflammation in A20myelKO mice was assessed in a time-dependent manner. Western blot analysis and quantitative PCR analysis were performed on bone marrow-derived macrophages from A20myelKO and littermate control mice to study the effect of A20 on STAT1/STAT3 expression and STAT1/STAT3-dependent gene transcription in myeloid cells. The in vivo role of Janus kinase-Signal Transducer and Activator of Transcription (JAK-STAT) signalling in the development of enthesitis in A20myelKO mice was assessed following administration of a JAK inhibitor versus placebo control. RESULTS: Enthesitis was found to be an early inflammatory lesion in A20myelKO mice. A20 negatively modulated STAT1-dependent, but generally not STAT3-dependent gene transcription in myeloid cells by suppressing STAT1 but not STAT3 expression, both in unstimulated conditions and after interferon-γ or interleukin-6 stimulation. The increase in STAT1 gene transcription in the absence of A20 was shown to be JAK-STAT-dependent. Moreover, JAK inhibition in vivo resulted in significant reduction of enthesitis, both clinically and histopathologically. CONCLUSIONS: Our data reveal an important and novel interplay between myeloid cells and tissue resident cells at entheseal sites that is regulated by A20. In the absence of A20, STAT1 but not STAT3 expression is enhanced leading to STAT1-dependent inflammation. Therefore, A20 acts as a novel endogenous regulator of STAT1 that prevents onset of enthesitis.


Assuntos
Entesopatia/genética , Entesopatia/metabolismo , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo , Animais , Células Cultivadas , Entesopatia/etiologia , Entesopatia/patologia , Inflamação/complicações , Inflamação/genética , Inflamação/metabolismo , Interferon gama/farmacologia , Interleucina-6/farmacologia , Janus Quinases/metabolismo , Macrófagos , Camundongos , Camundongos Knockout , Piperidinas/farmacologia , Pirimidinas/farmacologia , Pirróis/farmacologia , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/genética
5.
J Hepatol ; 60(1): 175-82, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23973929

RESUMO

BACKGROUND & AIMS: Immunometabolism is an emerging field of clinical investigation due to the obesity epidemic worldwide. A reciprocal involvement of immune mediators in the body energy metabolism has been recognized for years, but is only partially understood. We hypothesized that the adipokine leptin could provide an important modulator of iNKT cells. METHODS: The expression of leptin receptor (LR) on resting and activated iNKT cells was measured by flow cytometry. FACS-sorted hepatic iNKT cells were stimulated with anti-CD3/CD28Ab coated beads in the absence or presence of a neutralizing anti-leptin Ab. Furthermore, we evaluated the outcome of LR blocking nanobody treatment in ConA induced hepatitis and towards metabolic parameters in WT and iNKT cell deficient mice. RESULTS: The LR is expressed on iNKT cells and leptin suppresses iNKT cell proliferation and cytokine production in vitro. LR deficient iNKT cells are hyper-responsive further enforcing the role of leptin as an important inhibitor of iNKT cell function. Consistently, in vivo blockade of LR signaling exacerbated ConA hepatitis in wild-type but not in iNKT cell deficient mice, through both Janus kinase (JAK)2 and mitogen-activated protein kinase (MAPK) dependent mechanisms. Moreover, LR inhibition altered fat pad features and was accompanied by insulin resistance, only in wild-type mice. Curiously, this interaction was strictly dependent on MAPK mediated LR signaling in iNKT cells and uncoupled from the more central effects of leptin. CONCLUSIONS: Our data support a new concept of immune regulation by which leptin protects towards T cell mediated hepatitis via modulation of iNKT cells.


Assuntos
Adipócitos/fisiologia , Comunicação Celular , Hepatite/etiologia , Leptina/fisiologia , Células T Matadoras Naturais/fisiologia , Linfócitos T/imunologia , Tecido Adiposo/metabolismo , Animais , Suscetibilidade a Doenças , Ativação Linfocitária , Sistema de Sinalização das MAP Quinases , Camundongos , Receptores de Antígenos de Linfócitos T/fisiologia , Receptores para Leptina/fisiologia , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/fisiologia
6.
Ann Rheum Dis ; 73(2): 437-45, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23921997

RESUMO

OBJECTIVES: Spondyloarthritides (SpA) are characterised by both peripheral and axial arthritis. The hallmarks of peripheral SpA are the development of enthesitis, most typically of the Achilles tendon and plantar fascia, and new bone formation. This study was undertaken to unravel the mechanisms leading towards enthesitis and new bone formation in preclinical models of SpA. RESULTS: First, we demonstrated that TNF(ΔARE) mice show typical inflammatory features highly reminiscent of SpA. The first signs of inflammation were found at the entheses. Importantly, enthesitis occurred equally in the presence or absence of mature T and B cells, underscoring the importance of stromal cells. Hind limb unloading in TNF(ΔARE) mice significantly suppressed inflammation of the Achilles tendon compared with weight bearing controls. Erk1/2 signalling plays a crucial role in mechanotransduction-associated inflammation. Furthermore, new bone formation is strongly promoted at entheseal sites by biomechanical stress and correlates with the degree of inflammation. CONCLUSIONS: These findings provide a formal proof of the concept that mechanical strain drives both entheseal inflammation and new bone formation in SpA.


Assuntos
Tendão do Calcâneo/patologia , Artrite Experimental/complicações , Osteogênese/fisiologia , Espondilartrite/complicações , Tendinopatia/etiologia , Tendão do Calcâneo/fisiopatologia , Animais , Artrite Experimental/imunologia , Artrite Experimental/patologia , Artrite Experimental/fisiopatologia , Linfócitos B/imunologia , Sistema de Sinalização das MAP Quinases/fisiologia , Imageamento por Ressonância Magnética , Mecanotransdução Celular/fisiologia , Camundongos , Sacroileíte/etiologia , Sacroileíte/patologia , Espondilartrite/imunologia , Espondilartrite/patologia , Espondilartrite/fisiopatologia , Estresse Mecânico , Células Estromais/fisiologia , Linfócitos T/imunologia , Tendinopatia/imunologia , Tendinopatia/patologia , Tendinopatia/fisiopatologia , Fator de Necrose Tumoral alfa/imunologia , Suporte de Carga/fisiologia , Microtomografia por Raio-X
7.
Arthritis Rheumatol ; 75(11): 1969-1982, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37293832

RESUMO

OBJECTIVE: Patients with spondyloarthritis (SpA) often present with microscopic signs of gut inflammation, a risk factor for progressive disease. We investigated whether mucosal innate-like T cells are involved in dysregulated interleukin-23 (IL-23)/IL-17 responses in the gut-joint axis in SpA. METHODS: Ileal and colonic intraepithelial lymphocytes (IELs), lamina propria lymphocytes (LPLs), and paired peripheral blood mononuclear cells (PBMCs) were isolated from treatment-naive patients with nonradiographic axial SpA with (n = 11) and without (n = 14) microscopic gut inflammation and healthy controls (n = 15) undergoing ileocolonoscopy. The presence of gut inflammation was assessed histopathologically. Immunophenotyping of innate-like T cells and conventional T cells was performed using intracellular flow cytometry. Unsupervised clustering analysis was done by FlowSOM technology. Serum IL-17A levels were measured via Luminex. RESULTS: Microscopic gut inflammation in nonradiographic axial SpA was characterized by increased ileal intraepithelial γδ-hi T cells, a γδ-T cell subset with elevated γδ-T cell receptor expression. γδ-hi T cells were also increased in PBMCs of patients with nonradiographic axial SpA versus healthy controls and were strongly associated with Ankylosing Spondylitis Disease Activity Score. The abundance of mucosal-associated invariant T cells and invariant natural killer T cells was unaltered. Innate-like T cells in the inflamed gut showed increased RORγt, IL-17A, and IL-22 levels with loss of T-bet, a signature that was less pronounced in conventional T cells. Presence of gut inflammation was associated with higher serum IL-17A levels. In patients treated with tumor necrosis factor blockade, the proportion of γδ-hi cells and RORγt expression in blood was completely restored. CONCLUSION: Intestinal innate-like T cells display marked type 17 skewing in the inflamed gut mucosa of patients with nonradiographic axial SpA. γδ-hi T cells are linked to intestinal inflammation and disease activity in SpA.


Assuntos
Espondilartrite , Espondilite Anquilosante , Humanos , Interleucina-17/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares , Leucócitos Mononucleares/metabolismo , Inflamação/metabolismo , Espondilartrite/metabolismo , Mucosa/metabolismo
8.
Nat Commun ; 10(1): 9, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30602780

RESUMO

Dysregulated IL-23/IL-17 responses have been linked to psoriatic arthritis and other forms of spondyloarthritides (SpA). RORγt, the key Thelper17 (Th17) cell transcriptional regulator, is also expressed by subsets of innate-like T cells, including invariant natural killer T (iNKT) and γδ-T cells, but their contribution to SpA is still unclear. Here we describe the presence of particular RORγt+T-betloPLZF- iNKT and γδ-hi T cell subsets in healthy peripheral blood. RORγt+ iNKT and γδ-hi T cells show IL-23 mediated Th17-like immune responses and were clearly enriched within inflamed joints of SpA patients where they act as major IL-17 secretors. SpA derived iNKT and γδ-T cells showed unique and Th17-skewed phenotype and gene expression profiles. Strikingly, RORγt inhibition blocked γδ17 and iNKT17 cell function while selectively sparing IL-22+ subsets. Overall, our findings highlight a unique diversity of human RORγt+ T cells and underscore the potential of RORγt antagonism to modulate aberrant type 17 responses.


Assuntos
Células T Matadoras Naturais/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Espondilartrite/imunologia , Subpopulações de Linfócitos T/metabolismo , Estudos de Casos e Controles , Humanos , Interleucina-17/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/antagonistas & inibidores , Receptores de Interleucina/metabolismo
9.
Nat Commun ; 9(1): 5340, 2018 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-30559399

RESUMO

Activated invariant natural killer T (iNKT) cells rapidly produce large amounts of cytokines, but how cytokine mRNAs are induced, stabilized and mobilized following iNKT activation is still unclear. Here we show that an endoplasmic reticulum stress sensor, inositol-requiring enzyme 1α (IRE1α), links key cellular processes required for iNKT cell effector functions in specific iNKT subsets, in which TCR-dependent activation of IRE1α is associated with downstream activation of p38 MAPK and the stabilization of preformed cytokine mRNAs. Importantly, genetic deletion of IRE1α in iNKT cells reduces cytokine production and protects mice from oxazolone colitis. We therefore propose that an IRE1α-dependent signaling cascade couples constitutive cytokine mRNA expression to the rapid induction of cytokine secretion and effector functions in activated iNKT cells.


Assuntos
Citocinas/genética , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/genética , Ativação Linfocitária/imunologia , Células T Matadoras Naturais/imunologia , Proteínas Serina-Treonina Quinases/genética , Animais , Células Cultivadas , Colite/genética , Deleção de Genes , Camundongos , Camundongos Knockout , Oxazolona/toxicidade , RNA Mensageiro/genética , Transdução de Sinais , Resposta a Proteínas não Dobradas/genética , Resposta a Proteínas não Dobradas/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
10.
J Exp Med ; 213(10): 1973-81, 2016 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-27551157

RESUMO

Natural killer T (NKT) cells are innate lymphocytes that differentiate into NKT1, NKT2, and NKT17 sublineages during development. However, the signaling events that control NKT sublineage specification and differentiation remain poorly understood. Here, we demonstrate that the ubiquitin-modifying enzyme TNFAIP3/A20, an upstream regulator of T cell receptor (TCR) signaling in T cells, is an essential cell-intrinsic regulator of NKT differentiation. A20 is differentially expressed during NKT cell development, regulates NKT cell maturation, and specifically controls the differentiation and survival of NKT1 and NKT2, but not NKT17, sublineages. Remaining A20-deficient NKT1 and NKT2 thymocytes are hyperactivated in vivo and secrete elevated levels of Th1 and Th2 cytokines after TCR ligation in vitro. Defective NKT development was restored by compound deficiency of MALT1, a key downstream component of TCR signaling in T cells. These findings therefore show that negative regulation of TCR signaling during NKT development controls the differentiation and survival of NKT1 and NKT2 cells.


Assuntos
Linhagem da Célula , Células T Matadoras Naturais/citologia , Células T Matadoras Naturais/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo , Ubiquitina/metabolismo , Animais , Antígenos CD4/metabolismo , Caspases/deficiência , Caspases/metabolismo , Sobrevivência Celular , Integrases/metabolismo , Ativação Linfocitária/imunologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa , Proteínas de Neoplasias/deficiência , Proteínas de Neoplasias/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Regulação para Cima/genética
11.
Nat Genet ; 43(9): 908-12, 2011 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-21841782

RESUMO

A20 (TNFAIP3) is a protein that is involved in the negative feedback regulation of NF-κB signaling in response to specific proinflammatory stimuli in different cell types and has been suggested as a susceptibility gene for rheumatoid arthritis. To define the contribution of A20 to rheumatoid arthritis pathology, we generated myeloid-specific A20-deficient mice and show that specific ablation of Tnfaip3 in myeloid cells results in spontaneous development of a severe destructive polyarthritis with many features of rheumatoid arthritis. Myeloid-A20-deficient mice have high levels of inflammatory cytokines in their serum, consistent with a sustained NF-κB activation and higher TNF production by macrophages. Destructive polyarthritis in myeloid A20 knockout mice was TLR4-MyD88 and IL-6 dependent but was TNF independent. Myeloid A20 deficiency also promoted osteoclastogenesis in mice. Together, these observations indicate a critical and cell-specific function for A20 in the etiology of rheumatoid arthritis, supporting the idea of developing A20 modulatory drugs as cell-targeted therapies.


Assuntos
Artrite Reumatoide/genética , Artrite Reumatoide/patologia , Cisteína Endopeptidases/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Células Mieloides/enzimologia , Animais , Artrite Reumatoide/sangue , Citocinas/sangue , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , NF-kappa B/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Fator de Necrose Tumoral alfa/metabolismo
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