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1.
Front Immunol ; 13: 1046631, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36569931

RESUMO

Regulatory T cells (Tregs) normally maintain self-tolerance. Tregs recognize "self" such that when they are not working properly, such as in autoimmunity, the immune system can attack and destroy one's own tissues. Current therapies for autoimmunity rely on relatively ineffective and too often toxic therapies to "treat" the destructive inflammation. Restoring defective endogenous immune regulation (self-tolerance) would represent a paradigm shift in the therapy of these diseases. One recent approach to restore self-tolerance is to use "low dose IL-2" as a therapy to increase the number of circulating Tregs. However, studies to-date have not demonstrated that low-dose IL-2 therapy can restore concomitant Treg function, and phase 2 studies in low dose IL-2 treated patients with autoimmune diseases have failed to demonstrate significant clinical benefit. We hypothesize that the defect in self-tolerance seen in autoimmunity is not due to an insufficient number of available Tregs, but rather, due to defects in second messengers downstream of the IL-2R that normally control Treg function and stability. Previous studies from our lab and others have demonstrated that GRAIL (a ubiquitin E3 ligase) is important in Treg function. GRAIL expression is markedly diminished in Tregs from patients with autoimmune diseases and allergic asthma and is also diminished in Tregs of mice that are considered autoimmune prone. In the relevant pathway in Tregs, GRAIL normally blocks cullin ring ligase activity, which inhibits IL-2R desensitization in Tregs and consequently promotes Treg function. As a result of this defect in GRAIL expression, the Tregs of patients with autoimmune diseases and allergic asthma degrade IL-2R-associated pJAK1 following activation with low dose IL-2, and thus cannot maintain pSTAT5 expression. pSTAT5 controls the transcription of genes required for Treg function. Additionally, the GRAIL-mediated defect may also allow the degradation of the mTOR inhibitor, DEP domain-containing mTOR interacting protein (Deptor). This can lead to IL-2R activation of mTOR and loss of Treg stability in autoimmune patients. Using a monoclonal antibody to the remnant di-glycine tag on ubiquitinated proteins after trypsin digestion, we identified a protein that was ubiquitinated by GRAIL that is important in Treg function, cullin5. Our data demonstrate that GRAIL acts a negative regulator of IL-2R desensitization by ubiquitinating a lysine on cullin5 that must be neddylated to allow cullin5 cullin ring ligase activity. We hypothesize that a neddylation inhibitor in combination with low dose IL-2 activation could be used to substitute for GRAIL and restore Treg function and stability in the Tregs of autoimmune and allergic asthma patients. However, the neddylation activating enzyme inhibitors (NAEi) are toxic when given systemically. By generating a protein drug conjugate (PDC) consisting of a NAEi bound, via cleavable linkers, to a fusion protein of murine IL-2 (to target the drug to Tregs), we were able to use 1000-fold less of the neddylation inhibitor drug than the amount required for therapeutically effective systemic delivery. The PDC was effective in blocking the onset or the progression of disease in several mouse models of autoimmunity (type 1 diabetes, systemic lupus erythematosus, and multiple sclerosis) and a mouse model of allergic asthma in the absence of detectable toxicity. This PDC strategy represents targeted drug delivery at its best where the defect causing the disease was identified, a drug was designed and developed to correct the defect, and the drug was targeted and delivered only to cells that needed it, maximizing safety and efficacy.


Assuntos
Doenças Autoimunes , Linfócitos T Reguladores , Camundongos , Animais , Interleucina-2/metabolismo , Proteínas Culina/metabolismo , Receptores de Interleucina-2 , Doenças Autoimunes/metabolismo , Serina-Treonina Quinases TOR/metabolismo
2.
Diabetes ; 71(7): 1490-1507, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35499603

RESUMO

Multiple pathways contribute to the pathophysiological development of type 1 diabetes (T1D); however, the exact mechanisms involved are unclear. We performed differential gene expression analysis in pancreatic islets of NOD mice versus age-matched congenic NOD.B10 controls to identify genes that may contribute to disease pathogenesis. Novel genes related to extracellular matrix development and glucagon and insulin signaling/secretion were changed in NOD mice during early inflammation. During "respective" insulitis, the expression of genes encoding multiple chemosensory olfactory receptors were upregulated, and during "destructive" insulitis, the expression of genes involved in antimicrobial defense and iron homeostasis were downregulated. Islet inflammation reduced the expression of Hamp that encodes hepcidin. Hepcidin is expressed in ß-cells and serves as the key regulator of iron homeostasis. We showed that Hamp and hepcidin levels were lower, while iron levels were higher in the pancreas of 12-week-old NOD versus NOD.B10 mice, suggesting that a loss of iron homeostasis may occur in the islets during the onset of "destructive" insulitis. Interestingly, we showed that the severity of NOD disease correlates with dietary iron intake. NOD mice maintained on low-iron diets had a lower incidence of hyperglycemia, while those maintained on high-iron diets had an earlier onset and higher incidence of disease, suggesting that high iron exposure combined with a loss of pancreatic iron homeostasis may exacerbate NOD disease. This mechanism may explain the link seen between high iron exposure and the increased risk for T1D in humans.


Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Animais , Diabetes Mellitus Tipo 1/metabolismo , Hepcidinas/genética , Hepcidinas/metabolismo , Homeostase/genética , Inflamação/metabolismo , Ferro/metabolismo , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Pâncreas/metabolismo
3.
Front Endocrinol (Lausanne) ; 11: 609271, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33424774

RESUMO

Type 1 Diabetes (T1D) occurs as a result of the autoimmune destruction of pancreatic ß-cells by self-reactive T cells. The etiology of this disease is complex and difficult to study due to a lack of disease-relevant tissues from pre-diabetic individuals. In this study, we performed gene expression analysis on human pancreas tissues obtained from the Network of Pancreatic Organ Donors with Diabetes (nPOD), and showed that 155 genes were differentially expressed by ≥2-fold in the pancreata of autoantibody-positive (AA+) at-risk individuals compared to healthy controls. Only 48 of these genes remained changed by ≥2-fold in the pancreata of established T1D patients. Pathway analysis of these genes showed a significant association with various immune pathways. We were able to validate the differential expression of eight disease-relevant genes by QPCR analysis: A significant upregulation of CADM2, and downregulation of TRPM5, CRH, PDK4, ANGPL4, CLEC4D, RSG16, and FCGR2B was confirmed in the pancreata of AA+ individuals versus controls. Studies have already implicated FCGR2B in the pathogenesis of disease in non-obese diabetic (NOD) mice. Here we showed that CADM2, TRPM5, PDK4, and ANGPL4 were similarly changed in the pancreata of pre-diabetic 12-week-old NOD mice compared to NOD.B10 controls, suggesting a possible role for these genes in the pathogenesis of both T1D and NOD disease. The loss of the leukocyte-specific gene, FCGR2B, in the pancreata of AA+ individuals, is particularly interesting, as it may serve as a potential whole blood biomarker of disease progression. To test this, we quantified FCGR2B expression in peripheral blood samples of T1D patients, and AA+ and AA- first-degree relatives of T1D patients enrolled in the TrialNet Pathway to Prevention study. We showed that FCGR2B was significantly reduced in the peripheral blood of AA+ individuals compared to AA- controls. Together, these findings demonstrate that gene expression analysis of pancreatic tissue and peripheral blood samples can be used to identify disease-relevant genes and pathways and potential biomarkers of disease progression in T1D.


Assuntos
Diabetes Mellitus Tipo 1/genética , Perfilação da Expressão Gênica/métodos , Pâncreas/química , Estado Pré-Diabético/genética , Adolescente , Adulto , Animais , Autoanticorpos/genética , Autoanticorpos/imunologia , Biomarcadores/análise , Criança , Diabetes Mellitus Tipo 1/patologia , Progressão da Doença , Feminino , Regulação da Expressão Gênica , Humanos , Lactente , Masculino , Camundongos , Camundongos Endogâmicos NOD , Análise em Microsséries , Pessoa de Meia-Idade , Prognóstico , RNA/genética , Receptores de IgG/genética , Transdução de Sinais/genética , Adulto Jovem
4.
Proc Natl Acad Sci U S A ; 115(27): 7081-7086, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29915045

RESUMO

Although certain dogma portrays amyloid fibrils as drivers of neurodegenerative disease and neuroinflammation, we have found, paradoxically, that amyloid fibrils and small heat shock proteins (sHsps) are therapeutic in experimental autoimmune encephalomyelitis (EAE). They reduce clinical paralysis and induce immunosuppressive pathways, diminishing inflammation. A key question was the identification of the target for these molecules. When sHsps and amyloid fibrils were chemically cross-linked to immune cells, a limited number of proteins were precipitated, including the α7 nicotinic acetylcholine receptor (α7 NAChR). The α7 NAChR is noteworthy among the over 20 known receptors for amyloid fibrils, because it plays a central role in a well-defined immune-suppressive pathway. Competitive binding between amyloid fibrils and α-bungarotoxin to peritoneal macrophages (MΦs) confirmed the involvement of α7 NAChR. The mechanism of immune suppression was explored, and, similar to nicotine, amyloid fibrils inhibited LPS induction of a common set of inflammatory cytokines while inducing Stat3 signaling and autophagy. Consistent with this, previous studies have established that nicotine, sHsps, and amyloid fibrils all were effective therapeutics in EAE. Interestingly, B lymphocytes were needed for the therapeutic effect. These results suggest that agonists of α7 NAChR might have therapeutic benefit for a variety of inflammatory diseases.


Assuntos
Amiloide/imunologia , Encefalomielite Autoimune Experimental/imunologia , Proteínas de Choque Térmico/imunologia , Macrófagos Peritoneais/imunologia , Nicotina/imunologia , Receptor Nicotínico de Acetilcolina alfa7/imunologia , Animais , Linfócitos B/imunologia , Linfócitos B/patologia , Encefalomielite Autoimune Experimental/patologia , Humanos , Tolerância Imunológica , Macrófagos Peritoneais/patologia , Camundongos
5.
BMC Genomics ; 18(1): 636, 2017 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-28821222

RESUMO

BACKGROUND: The natural history of type 1 diabetes (T1D) is challenging to investigate, especially as pre-diabetic individuals are difficult to identify. Numerous T1D consortia have been established to collect whole blood for gene expression analysis from individuals with or at risk to develop T1D. However, with no universally accepted protocol for their collection, differences in sample processing may lead to variances in the results. Here, we examined whether the choice of blood collection tube and RNA extraction kit leads to differences in the expression of genes that are changed during the progression of T1D, and if these differences could be minimized by measuring gene expression directly from the lysate of whole blood. RESULTS: Microarray analysis showed that the expression of 901 genes is highly influenced by sample processing using the PAXgene versus the Tempus system. These included a significant number of lymphocyte-specific genes and genes whose expression has been reported to differ in the peripheral blood of at-risk and T1D patients compared to controls. We showed that artificial changes in gene expression occur when control and T1D samples were processed differently. The sample processing-dependent differences in gene expression were largely due to loss of transcripts during the RNA extraction step using the PAXgene system. The majority of differences were not observed when gene expression was measured in whole blood lysates prepared from blood collected in PAXgene and Tempus tubes. CONCLUSION: We showed that the gene expression profile of samples processed using the Tempus system is more accurate than that of samples processed using the PAXgene system. Variation in sample processing can result in misleading changes in gene expression. However, these differences can be minimized by measuring gene expression directly in whole blood lysates.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/genética , Perfilação da Expressão Gênica/métodos , Leucócitos Mononucleares/metabolismo , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Adulto Jovem
6.
Diabetes ; 65(5): 1341-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26983959

RESUMO

Type 1 diabetes (T1D) is caused by autoreactive T cells that recognize pancreatic islet antigens and destroy insulin-producing ß-cells. This attack results from a breakdown in tolerance for self-antigens, which is controlled by ectopic antigen expression in the thymus and pancreatic lymph nodes (PLNs). The autoantigens known to be involved include a set of islet proteins, such as insulin, GAD65, IA-2, and ZnT8. In an attempt to identify additional antigenic proteins, we performed an expression-based genome-wide association study using microarray data from 118 arrays of the thymus and PLNs of T1D mice. We ranked all 16,089 protein-coding genes by the likelihood of finding repeated differential expression and the degree of tissue specificity for pancreatic islets. The top autoantigen candidate was vitamin D-binding protein (VDBP). T-cell proliferation assays showed stronger T-cell reactivity to VDBP compared with control stimulations. Higher levels and frequencies of serum anti-VDBP autoantibodies (VDBP-Abs) were identified in patients with T1D (n = 331) than in healthy control subjects (n = 77). Serum vitamin D levels were negatively correlated with VDBP-Ab levels in patients in whom T1D developed during the winter. Immunohistochemical localization revealed that VDBP was specifically expressed in α-cells of pancreatic islets. We propose that VDBP could be an autoantigen in T1D.


Assuntos
Autoantígenos/metabolismo , Doenças Autoimunes/metabolismo , Autoimunidade , Diabetes Mellitus Tipo 1/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Células Secretoras de Glucagon/metabolismo , Proteína de Ligação a Vitamina D/metabolismo , Adolescente , Animais , Autoantígenos/genética , Doenças Autoimunes/sangue , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Estudos de Casos e Controles , Células Cultivadas , Criança , Pré-Escolar , Colorado , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Feminino , Estudo de Associação Genômica Ampla , Células Secretoras de Glucagon/imunologia , Células Secretoras de Glucagon/patologia , Humanos , Masculino , Camundongos Endogâmicos NOD , Especificidade de Órgãos , Estações do Ano , Baço/citologia , Baço/imunologia , Baço/metabolismo , Baço/patologia , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/patologia , Vitamina D/análogos & derivados , Vitamina D/sangue , Proteína de Ligação a Vitamina D/genética
7.
Stem Cells ; 34(4): 809-19, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26840009

RESUMO

The evolution of Type 1 diabetes (T1D) therapy has been marked by consecutive shifts, from insulin replacement to immunosuppressive drugs and targeted biologics (following the understanding that T1D is an autoimmune disease), and to more disease-specific or patient-oriented approaches such as antigen-specific and cell-based therapies, with a goal to provide efficacy, safety, and long-term protection. At the same time, another important paradigm shift from treatment of new onset T1D patients to prevention in high-risk individuals has taken place, based on the hypothesis that therapeutic approaches deemed sufficiently safe may show better efficacy if applied early enough to maintain endogenous ß cell function, a concept supported by many preclinical studies. This new strategy has been made possible by capitalizing on a variety of biomarkers that can more reliably estimate the risk and rate of progression of the disease. More advanced ("omic"-based) biomarkers that also shed light on the underlying contributors of disease for each individual will be helpful to guide the choice of the most appropriate therapies, or combinations thereof. In this review, we present current efforts to stratify patients according to biomarkers and current alternatives to conventional drug-based therapies for T1D, with a special emphasis on cell-based therapies, their status in the clinic and potential for treatment and/or prevention.


Assuntos
Autoimunidade , Terapia Baseada em Transplante de Células e Tecidos , Diabetes Mellitus Tipo 1/terapia , Células Secretoras de Insulina/patologia , Biomarcadores/metabolismo , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/transplante , Transplante de Células-Tronco Mesenquimais , Linfócitos T/imunologia , Linfócitos T/metabolismo
8.
Proc Natl Acad Sci U S A ; 112(49): 15016-23, 2015 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-26621719

RESUMO

Amyloid fibrils composed of peptides as short as six amino acids are therapeutic in experimental autoimmune encephalomyelitis (EAE), reducing paralysis and inflammation, while inducing several pathways of immune suppression. Intraperitoneal injection of fibrils selectively activates B-1a lymphocytes and two populations of resident macrophages (MΦs), increasing IL-10 production, and triggering their exodus from the peritoneum. The importance of IL-10-producing B-1a cells in this effective therapy was established in loss-of-function experiments where neither B-cell-deficient (µMT) nor IL10(-/-) mice with EAE responded to the fibrils. In gain-of-function experiments, B-1a cells, adoptively transferred to µMT mice with EAE, restored their therapeutic efficacy when Amylin 28-33 was administered. Stimulation of adoptively transferred bioluminescent MΦs and B-1a cells by amyloid fibrils resulted in rapid (within 60 min of injection) trafficking of both cell types to draining lymph nodes. Analysis of gene expression indicated that the fibrils activated the CD40/B-cell receptor pathway in B-1a cells and induced a set of immune-suppressive cell-surface proteins, including BTLA, IRF4, and Siglec G. Collectively, these data indicate that the fibrils activate B-1a cells and F4/80(+) MΦs, resulting in their migration to the lymph nodes, where IL-10 and cell-surface receptors associated with immune-suppression limit antigen presentation and T-cell activation. These mechanisms culminate in reduction of paralytic signs of EAE.


Assuntos
Amiloide/farmacologia , Linfócitos B/imunologia , Encefalomielite Autoimune Experimental/tratamento farmacológico , Ativação Linfocitária/efeitos dos fármacos , Transferência Adotiva , Amiloide/metabolismo , Amiloide/uso terapêutico , Animais , Encefalomielite Autoimune Experimental/imunologia , Endocitose , Feminino , Interleucina-10/fisiologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/farmacologia , Camundongos , Camundongos Endogâmicos C57BL
9.
PLoS One ; 10(7): e0133627, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26197454

RESUMO

While many age-associated immune changes have been reported, a comprehensive set of metrics of immune aging is lacking. Here we report data from 243 healthy adults aged 40-97, for whom we measured clinical and functional parameters, serum cytokines, cytokines and gene expression in stimulated and unstimulated PBMC, PBMC phenotypes, and cytokine-stimulated pSTAT signaling in whole blood. Although highly heterogeneous across individuals, many of these assays revealed trends by age, sex, and CMV status, to greater or lesser degrees. Age, then sex and CMV status, showed the greatest impact on the immune system, as measured by the percentage of assay readouts with significant differences. An elastic net regression model could optimally predict age with 14 analytes from different assays. This reinforces the importance of multivariate analysis for defining a healthy immune system. These data provide a reference for others measuring immune parameters in older people.


Assuntos
Envelhecimento , Sistema Imunitário/fisiologia , Leucócitos Mononucleares/citologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , California , Quimiocina CCL7/metabolismo , Citocinas/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Nitrogênio/química , Fenótipo , Análise de Regressão , Transdução de Sinais , Inquéritos e Questionários , Ureia/química
10.
Arthritis Res Ther ; 17: 127, 2015 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-25981462

RESUMO

The development of biomarkers for autoimmune diseases has been hampered by a lack of understanding of disease etiopathogenesis and of the mechanisms underlying the induction and maintenance of inflammation, which involves complex activation dynamics of diverse cell types. The heterogeneous nature and suboptimal clinical response to treatment observed in many autoimmune syndromes highlight the need to develop improved strategies to predict patient outcome to therapy and personalize patient care. Mass cytometry, using CyTOF®, is an advanced technology that facilitates multiparametric, phenotypic analysis of immune cells at single-cell resolution. In this review, we outline the capabilities of mass cytometry and illustrate the potential of this technology to enhance the discovery of cellular biomarkers for rheumatoid arthritis, a prototypical autoimmune disease.


Assuntos
Artrite Reumatoide/imunologia , Espectrometria de Massas/métodos , Análise de Célula Única/métodos , Artrite Reumatoide/sangue , Biomarcadores/análise , Feminino , Humanos , Masculino , Sensibilidade e Especificidade , Índice de Gravidade de Doença
12.
Diabetes ; 64(2): 604-17, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25187368

RESUMO

Peripheral tolerance is partially controlled by the expression of peripheral tissue antigens (PTAs) in lymph node stromal cells (LNSCs). We previously identified a transcriptional regulator, deformed epidermal autoregulatory factor 1 (Deaf1), that can regulate PTA expression in LNSCs of the pancreatic lymph nodes (PLNs). During the pathogenesis of type 1 diabetes (T1D), Deaf1 is spliced to form the dominant-negative isoform Deaf1-Var1. Here we show that Deaf1-Var1 expression correlates with the severity of disease in NOD mice and is reduced in the PLNs of mice that do not develop hyperglycemia. Inflammation and hyperglycemia independently drive Deaf1 splicing through activation of the splicing factors Srsf10 and Ptbp2, respectively. Inflammation induced by injection of activated splenocytes increased Deaf1-Var1 and Srsf10, but not Ptbp2, in the PLNs of NOD.SCID mice. Hyperglycemia induced by treatment with the insulin receptor agonist S961 increased Deaf1-Var1 and Ptbp2, but not Srsf10, in the PLNs of NOD.B10 and NOD mice. Overexpression of PTBP2 and/or SRSF10 also increased human DEAF1-VAR1 and reduced PTA expression in HEK293T cells. These data suggest that during the progression of T1D, inflammation and hyperglycemia mediate the splicing of DEAF1 and loss of PTA expression in LNSCs by regulating the expression of SRSF10 and PTBP2.


Assuntos
Processamento Alternativo , Diabetes Mellitus Tipo 1/metabolismo , Hiperglicemia/metabolismo , Inflamação/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Envelhecimento , Animais , Glicemia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA , Diabetes Mellitus Tipo 1/genética , Feminino , Células HEK293 , Humanos , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Linfonodos/fisiologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/genética , Pâncreas/fisiologia , Elastase Pancreática/genética , Elastase Pancreática/metabolismo , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Processamento de Serina-Arginina , Baço/citologia , Fatores de Transcrição/genética
13.
J Exp Med ; 211(9): 1847-56, 2014 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-25073790

RESUMO

Amyloid fibrils composed of peptides as short as six amino acids are effective therapeutics for experimental autoimmune encephalomyelitis (EAE). Immunosuppression arises from at least two pathways: (1) expression of type 1 IFN by pDCs, which were induced by neutrophil extracellular traps arising from the endocytosis of the fibrils; and (2) the reduced expression of IFN-γ, TNF, and IL-6. The two independent pathways stimulated by the fibrils can act in concert to be immunosuppressive in Th1 indications, or in opposition, resulting in inflammation when Th17 T lymphocytes are predominant. The generation of type 1 IFN can be minimized by using polar, nonionizable, amyloidogenic peptides, which are effective in both Th1 and Th17 polarized EAE.


Assuntos
Amiloide/imunologia , Amiloide/uso terapêutico , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/terapia , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/uso terapêutico , Transferência Adotiva , Adulto , Animais , Encefalomielite Autoimune Experimental/genética , Feminino , Expressão Gênica , Humanos , Imunossupressores/uso terapêutico , Interferon Tipo I/metabolismo , Interferon gama/metabolismo , Interleucina-6/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Th1/imunologia , Células Th17/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Proteínas tau/imunologia , Proteínas tau/uso terapêutico
14.
Immunol Res ; 58(2-3): 340-50, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24682832

RESUMO

Type 1 diabetes (T1D) is a complex polygenic disease that is triggered by various environmental factors in genetically susceptible individuals. The emphasis placed on genome-wide association studies to explain the genetics of T1D has failed to advance our understanding of T1D pathogenesis or identify biomarkers of disease progression or therapeutic targets. Using the nonobese diabetic (NOD) mouse model of T1D and the non-disease prone congenic NOD.B10 mice, our laboratory demonstrated striking tissue-specific and age-dependent changes in gene expression during disease progression. We established a "roadmap" of differential gene expression and used this to identify candidate genes in mice (and human orthologs) that play a role in disease pathology. Here, we describe two genes, Deformed epidermal autoregulatory factor 1 (Deaf1) and Adenosine A1 receptor (Adora1), that are differentially expressed and alternatively spliced in the pancreatic lymph nodes or islets of NOD mice and T1D patients to form dominant-negative non-functional isoforms. Loss of Deaf1 function leads to reduced peripheral tissue antigen expression in lymph node stromal cells and may contribute to a breakdown in peripheral tolerance, while reduced Adora1 function results in an early intrinsic alpha cell defect that may explain the hyperglucagonemia and resulting beta cell stress observed prior to the onset of diabetes. Remarkably, both genes were also alternatively spliced in the same tissues of auto-antibody positive prediabetic patients, and these splicing events resulted in similar downstream effects as those seen in NOD mice. These findings demonstrate the value of gene expression profiling in studying disease pathogenesis in T1D.


Assuntos
Diabetes Mellitus Tipo 1/etiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Processamento Alternativo , Animais , Apresentação de Antígeno/imunologia , Antígenos/genética , Antígenos/imunologia , Proteínas de Ligação a DNA , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/terapia , Modelos Animais de Doenças , Humanos , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Proteínas Nucleares/genética , Especificidade de Órgãos/genética , Receptor A1 de Adenosina/metabolismo , Fatores de Transcrição , Pesquisa Translacional Biomédica
15.
Wilderness Environ Med ; 25(2): 160-5, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24631228

RESUMO

BACKGROUND: Frostbite injury occurs when exposure to cold results in frozen tissue. We recently reported a novel mouse model for frostbite injury to be used in screening potentially therapeutic drugs and other modalities. OBJECTIVE: We used the mouse skin frostbite model to evaluate the effect of poly-l-arginine contained in lotion (PAL) applied topically to involved skin. METHODS: Sixty mice were studied in a randomized, double-blind method. Standardized 2.9-cm-diameter circles were tattooed on the mouse dorsum. Magnets snap frozen in dry ice (-78.5°C) were used to create a frostbite injury on skin within the circle as a continuous 5-minute freeze. Mice were treated with prefreeze placebo, postthaw placebo, combined prefreeze and postthaw placebo, prefreeze with PAL, postthaw with PAL, or combined prefreeze and postthaw with PAL. Appearance, healing rate, tissue loss, and histology were recorded until the wounds were healed. RESULTS: Application of PAL before inducing frostbite injury resulted in decreased tissue loss as compared with other treatment conditions. CONCLUSIONS: Applying PAL topically to frostbitten mouse skin caused decreased tissue loss. Poly-l-arginine should be studied further to determine whether it is a beneficial therapeutic modality for frostbite injury.


Assuntos
Congelamento das Extremidades/tratamento farmacológico , Peptídeos/administração & dosagem , Animais , Modelos Animais de Doenças , Congelamento das Extremidades/patologia , Masculino , Camundongos Endogâmicos C57BL , Peptídeos/farmacologia , Cicatrização/efeitos dos fármacos
17.
Diabetes ; 62(12): 4208-19, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24264405

RESUMO

Prediabetic NOD mice exhibit hyperglucagonemia, possibly due to an intrinsic α-cell defect. Here, we show that the expression of a potential glucagon inhibitor, the adenosine A1 receptor (Adora1), is gradually diminished in α-cells of NOD mice, autoantibody-positive (AA(+)) and overtly type 1 diabetic (T1D) patients during the progression of disease. We demonstrated that islet inflammation was associated with loss of Adora1 expression through the alternative splicing of Adora1. Expression of the spliced variant (Adora1-Var) was upregulated in the pancreas of 12-week-old NOD versus age-matched NOD.B10 (non-diabetes-susceptible) control mice and was detected in the pancreas of AA(+) patients but not in control subjects or overtly diabetic patients, suggesting that inflammation drives the splicing of Adora1. We subsequently demonstrated that Adora1-Var expression was upregulated in the islets of NOD.B10 mice after exposure to inflammatory cytokines and in the pancreas of NOD.SCID mice after adoptive transfer of activated autologous splenocytes. Adora1-Var encodes a dominant-negative N-terminal truncated isoform of Adora1. The splicing of Adora1 and loss of Adora1 expression on α-cells may explain the hyperglucagonemia observed in prediabetic NOD mice and may contribute to the pathogenesis of human T1D and NOD disease.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Células Secretoras de Glucagon/metabolismo , Estado Pré-Diabético/metabolismo , Receptor A1 de Adenosina/metabolismo , Adolescente , Adulto , Animais , Criança , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Feminino , Humanos , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Pessoa de Meia-Idade , Estado Pré-Diabético/genética , Estado Pré-Diabético/patologia , Receptor A1 de Adenosina/genética , Baço/metabolismo , Baço/patologia
18.
J Mol Cell Biol ; 5(2): 99-110, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22923498

RESUMO

The transcriptional regulator deformed epidermal autoregulatory factor 1 (DEAF1) has been suggested to play a role in maintaining peripheral tolerance by controlling the transcription of peripheral tissue antigen genes in lymph node stromal cells (LNSCs). Here, we demonstrate that DEAF1 also regulates the translation of genes in LNSCs by controlling the transcription of the poorly characterized eukaryotic translation initiation factor 4 gamma 3 (Eif4g3) that encodes eIF4GII. Eif4g3 gene expression was reduced in the pancreatic lymph nodes of Deaf1-KO mice, non-obese diabetic mice, and type 1 diabetes patients, where functional Deaf1 is absent or diminished. Silencing of Deaf1 reduced Eif4g3 expression, but increased the expression of Caspase 3, a serine protease that degrades eIF4GII. Polysome profiling showed that reduced Eif4g3 expression in LNSCs resulted in the diminished translation of various genes, including Anpep, the gene for aminopeptidase N, an enzyme involved in fine-tuning antigen presentation on major histocompatibility complex (MHC) class II. Together these findings suggest that reduced DEAF1 function, and subsequent loss of Eif4g3 transcription may affect peripheral tissue antigen (PTA) expression in LNSCs and contribute to the pathology of T1D.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Fator de Iniciação Eucariótico 4G/biossíntese , Linfonodos/metabolismo , Pâncreas/metabolismo , Biossíntese de Proteínas , Fatores de Transcrição/metabolismo , Animais , Caspase 3/biossíntese , Caspase 3/genética , Caspase 3/imunologia , Proteínas de Ligação a DNA , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Fator de Iniciação Eucariótico 4G/genética , Fator de Iniciação Eucariótico 4G/imunologia , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Tolerância Imunológica/genética , Linfonodos/imunologia , Linfonodos/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos Knockout , Pâncreas/imunologia , Pâncreas/patologia , Células Estromais/imunologia , Células Estromais/metabolismo , Células Estromais/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/imunologia
19.
Nat Chem Biol ; 8(12): 990-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23103943

RESUMO

Cytokines dimerize their receptors, with the binding of the 'second chain' triggering signaling. In the interleukin (IL)-4 and IL-13 system, different cell types express varying numbers of alternative second receptor chains (γc or IL-13Rα1), forming functionally distinct type I or type II complexes. We manipulated the affinity and specificity of second chain recruitment by human IL-4. A type I receptor-selective IL-4 'superkine' with 3,700-fold higher affinity for γc was three- to ten-fold more potent than wild-type IL-4. Conversely, a variant with high affinity for IL-13Rα1 more potently activated cells expressing the type II receptor and induced differentiation of dendritic cells from monocytes, implicating the type II receptor in this process. Superkines showed signaling advantages on cells with lower second chain numbers. Comparative transcriptional analysis reveals that the superkines induce largely redundant gene expression profiles. Variable second chain numbers can be exploited to redirect cytokines toward distinct cell subsets and elicit new actions, potentially improving the selectivity of cytokine therapy.


Assuntos
Citocinas/fisiologia , Interleucina-4/análogos & derivados , Interleucina-4/farmacologia , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Células Dendríticas/efeitos dos fármacos , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Fatores Imunológicos/farmacologia , Interleucina-4/química , Mutação/fisiologia , Fenótipo , Fosforilação , Engenharia de Proteínas , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Interleucina-4/efeitos dos fármacos , Fator de Transcrição STAT6/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade
20.
Nat Rev Rheumatol ; 8(6): 317-28, 2012 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-22647780

RESUMO

Rheumatologists see patients with a range of autoimmune diseases. Phenotyping these diseases for diagnosis, prognosis and selection of therapies is an ever increasing problem. Advances in multiplexed assay technology at the gene, protein, and cellular level have enabled the identification of 'actionable biomarkers'; that is, biological metrics that can inform clinical practice. Not only will such biomarkers yield insight into the development, remission, and exacerbation of a disease, they will undoubtedly improve diagnostic sensitivity and accuracy of classification, and ultimately guide treatment. This Review provides an introduction to these powerful technologies that could promote the identification of actionable biomarkers, including mass cytometry, protein arrays, and immunoglobulin and T-cell receptor high-throughput sequencing. In our opinion, these technologies should become part of routine clinical practice for the management of autoimmune diseases. The use of analytical tools to deconvolve the data obtained from use of these technologies is also presented here. These analyses are revealing a more comprehensive and interconnected view of the immune system than ever before and should have an important role in directing future treatment approaches for autoimmune diseases.


Assuntos
Doenças Autoimunes/classificação , Biomarcadores/metabolismo , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/terapia , Citometria de Fluxo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunoensaio , Imunoglobulinas/genética , Imunofenotipagem , Espectrometria de Massas , Monitorização Fisiológica , Prognóstico , Análise Serial de Proteínas , Receptores de Antígenos de Linfócitos T/genética , Análise de Sequência de DNA
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