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1.
J Immunol ; 212(2): 258-270, 2024 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-38079221

RESUMO

Oxidants participate in lymphocyte activation and function. We previously demonstrated that eliminating the activity of NADPH oxidase 2 (NOX2) significantly impaired the effectiveness of autoreactive CD8+ CTLs. However, the molecular mechanisms impacting CD8+ T cell function remain unknown. In the present study, we examined the role of NOX2 in both NOD mouse and human CD8+ T cell function. Genetic ablation or chemical inhibition of NOX2 in CD8+ T cells significantly suppressed activation-induced expression of the transcription factor T-bet, the master transcription factor of the Tc1 cell lineage, and T-bet target effector genes such as IFN-γ and granzyme B. Inhibition of NOX2 in both human and mouse CD8+ T cells prevented target cell lysis. We identified that superoxide generated by NOX2 must be converted into hydrogen peroxide to transduce the redox signal in CD8+ T cells. Furthermore, we show that NOX2-generated oxidants deactivate the tumor suppressor complex leading to activation of RheB and subsequently mTOR complex 1. These results indicate that NOX2 plays a nonredundant role in TCR-mediated CD8+ T cell effector function.


Assuntos
Linfócitos T CD8-Positivos , NADPH Oxidase 2 , Espécies Reativas de Oxigênio , Animais , Humanos , Camundongos , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Citocinas/imunologia , Granzimas/metabolismo , Peróxido de Hidrogênio/metabolismo , Inflamação/imunologia , Interferon gama/metabolismo , Ativação Linfocitária , Camundongos Endogâmicos NOD , NADPH Oxidase 2/antagonistas & inibidores , NADPH Oxidase 2/metabolismo , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais , Proteínas com Domínio T/metabolismo , Masculino , Feminino , Adulto Jovem
2.
Am J Physiol Lung Cell Mol Physiol ; 323(6): L715-L729, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36255715

RESUMO

Human COPA mutations affecting retrograde Golgi-to-endoplasmic reticulum (ER) protein transport cause diffuse alveolar hemorrhage (DAH) and ER stress ("COPA syndrome"). Patients with SLE also can develop DAH. C57BL/6 (B6) mice with pristane-induced lupus develop monocyte-dependent DAH indistinguishable from human DAH, whereas BALB/c mice are resistant. We examined Copa and ER stress in pristane-induced lupus. Copa expression, ER stress, vascular injury, and apoptosis were assessed in mice and COPA was quantified in blood from patients with SLE. Copa mRNA and protein expression were impaired in B6 mice with pristane-induced DAH, but not in pristane-treated BALB/c mice. An ER stress response (increased Hsp5a/BiP, Ddit3/CHOP, Eif2a, and spliced Xbp1) was seen in lungs from pristane-treated B6, but not BALB/c, mice. Resistance of BALB/c mice to DAH was overcome by treating them with low-dose thapsigargin plus pristane. CB6F1 mice did not develop DAH or ER stress, suggesting that susceptibility was recessive. Increased pulmonary expression of von Willebrand factor (Vwf), a marker of endothelial injury, and the chemokine Ccl2 in DAH suggested that pristane promotes lung microvascular injury and monocyte recruitment. Consistent with that possibility, lung endothelial cells and infiltrating bone marrow-derived cells from pristane-treated B6 mice expressed BiP and showed evidence of apoptosis (annexin-V and activated caspase-3 staining). COPA expression also was low in patients with SLE with lung involvement. Pristane-induced DAH may be initiated by endothelial injury, resulting in ER stress, apoptosis of lung endothelial cells, and recruitment of myeloid cells that propagate lung injury. The pathogenesis of DAH in SLE and COPA syndrome may overlap.


Assuntos
Pneumopatias , Lesão Pulmonar , Lúpus Eritematoso Sistêmico , Vasculite , Humanos , Camundongos , Animais , Alvéolos Pulmonares/patologia , Lesão Pulmonar/patologia , Células Endoteliais/patologia , Camundongos Endogâmicos C57BL , Pulmão/patologia , Pneumopatias/patologia , Hemorragia , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/induzido quimicamente , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Vasculite/patologia , Estresse do Retículo Endoplasmático
3.
J Clin Immunol ; 42(6): 1270-1279, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35588029

RESUMO

PURPOSE: Common variable immunodeficiency (CVID) is the most prevalent symptomatic immunodeficiency in adults. Little is known about the manifestations of CVID presenting in older adults. Herein, we performed a phenotypic characterization of patients diagnosed older than age 40. METHODS: A retrospective chart review of 79 patients seen at UF Health between 2006 and 2020 with a verified diagnosis of CVID per the ICON 2016 criteria was conducted. Patients were classified according to four phenotypes: no-disease-related complications, autoimmune cytopenias, polyclonal lymphoproliferation, and unexplained enteropathy. Patients diagnosed with CVID from age 2 to 40 (n = 41, "younger cohort") were compared to patients diagnosed with CVID age 41 and older (n = 38, "older cohort"). RESULTS: Among the younger cohort, pathologic genetic variants, positive family history for immunodeficiency, autoimmunity (49% vs 24%, p = 0.03), and splenomegaly (46% vs 16%, p = 0.004) were more common, as was the "autoimmune cytopenias" phenotype (24% vs 3%, p = 0.007). Among the older cohort, lymphoma (11% vs 0%, p = 0.049) and the "no disease-related complications" phenotype (79% vs 57%, p = 0.03) were more commonly seen. Comorbidities such as bronchiectasis (27% vs 21%, p = 0.61), GI involvement (34% vs 24%, p = 0.33), and GLILD (5% vs 8%, p = 0.67) were equally present among both the younger and older cohorts, respectively. CONCLUSION: The lower incidence of autoimmunity and splenomegaly, as well as overlapping clinical features with immunosenescence, may make diagnosing CVID in older patients more challenging; however, the disease is not more indolent as the risks for lymphoma, bronchiectasis, and GLILD are similar to those of younger patients.


Assuntos
Bronquiectasia , Imunodeficiência de Variável Comum , Leucopenia , Bronquiectasia/diagnóstico , Bronquiectasia/epidemiologia , Bronquiectasia/etiologia , Imunodeficiência de Variável Comum/diagnóstico , Imunodeficiência de Variável Comum/epidemiologia , Imunodeficiência de Variável Comum/genética , Humanos , Fenótipo , Estudos Retrospectivos , Esplenomegalia/complicações , Esplenomegalia/etiologia
4.
Clin Immunol ; 229: 108764, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34089860

RESUMO

C57BL/6 mice with pristane-induced lupus develop macrophage-dependent diffuse alveolar hemorrhage (DAH), which is blocked by treatment with liver X receptor (LXR) agonists and is exacerbated by low IL-10 levels. Serp-1, a myxomavirus-encoded serpin that impairs macrophage activation and plasminogen activation, blocks DAH caused by MHV68 infection. We investigated whether Serp-1 also could block DAH in pristane-induced lupus. Pristane-induced DAH was prevented by treatment with recombinant Serp-1 and macrophages from Serp1-treated mice exhibited an anti-inflammatory M2-like phenotype. Therapy activated LXR, promoting M2 polarization and expression of Kruppel-like factor-4 (KLH4), which upregulates IL-10. In contrast, deficiency of tissue plasminogen activator or plasminogen activator inhibitor had little effect on DAH. We conclude that Serp-1 blocks pristane-induced lung hemorrhage by enhancing LXR-regulated M2 macrophage polarization and KLH4-regulated IL-10 production. In view of the similarities between DAH in pristane-treated mice and SLE patients, Serp-1 may represent a potential new therapy for this severe complication of SLE.


Assuntos
Lúpus Eritematoso Sistêmico/terapia , Macrófagos/efeitos dos fármacos , Serpinas/farmacologia , Proteínas Virais/farmacologia , Animais , Coagulação Sanguínea , Feminino , Hemorragia/sangue , Hemorragia/patologia , Hemorragia/prevenção & controle , Interleucina-10/biossíntese , Fator 4 Semelhante a Kruppel , Receptores X do Fígado/metabolismo , Pneumopatias/sangue , Pneumopatias/patologia , Pneumopatias/prevenção & controle , Lúpus Eritematoso Sistêmico/induzido quimicamente , Lúpus Eritematoso Sistêmico/imunologia , Macrófagos/classificação , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Myxoma virus/genética , Células RAW 264.7 , Serpinas/genética , Terpenos/toxicidade , Proteínas Virais/genética
5.
J Immunol ; 199(4): 1261-1274, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28696256

RESUMO

Dead cells accumulating in the tissues may contribute to chronic inflammation. We examined the cause of impaired apoptotic cell clearance in human and murine lupus. Dead cells accumulated in bone marrow from lupus patients but not from nonautoimmune patients undergoing myeloablation, where they were efficiently removed by macrophages (MΦ). Impaired apoptotic cell uptake by MΦ also was seen in mice treated i.p. with pristane (develop lupus) but not mineral oil (MO) (do not develop lupus). The inflammatory response to both pristane and MO rapidly depleted resident (Tim4+) large peritoneal MΦ. The peritoneal exudate of pristane-treated mice contained mainly Ly6Chi inflammatory monocytes; whereas in MO-treated mice, it consisted predominantly of a novel subset of highly phagocytic MΦ resembling small peritoneal MΦ (SPM) that expressed CD138+ and the scavenger receptor Marco. Treatment with anti-Marco-neutralizing Abs and the class A scavenger receptor antagonist polyinosinic acid inhibited phagocytosis of apoptotic cells by CD138+ MΦ. CD138+ MΦ expressed IL-10R, CD206, and CCR2 but little TNF-α or CX3CR1. They also expressed high levels of activated CREB, a transcription factor implicated in generating alternatively activated MΦ. Similar cells were identified in the spleen and lung of MO-treated mice and also were induced by LPS. We conclude that highly phagocytic, CD138+ SPM-like cells with an anti-inflammatory phenotype may promote the resolution of inflammation in lupus and infectious diseases. These SPM-like cells are not restricted to the peritoneum and may help clear apoptotic cells from tissues such as the lung, helping to prevent chronic inflammation.


Assuntos
Lúpus Eritematoso Sistêmico/imunologia , Macrófagos Peritoneais/imunologia , Fagocitose , Sindecana-1/imunologia , Animais , Antígenos Ly/análise , Apoptose , Células da Medula Óssea/imunologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Modelos Animais de Doenças , Humanos , Inflamação/imunologia , Subunidade alfa de Receptor de Interleucina-10/genética , Subunidade alfa de Receptor de Interleucina-10/imunologia , Pulmão/citologia , Pulmão/imunologia , Lúpus Eritematoso Sistêmico/induzido quimicamente , Lúpus Eritematoso Sistêmico/fisiopatologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/patologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Óleo Mineral/farmacologia , Poli I/farmacologia , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Baço/citologia , Baço/imunologia , Sindecana-1/genética , Terpenos/farmacologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
6.
Biochim Biophys Acta ; 1861(2): 130-137, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26569053

RESUMO

AIM: Atypical angiopoietin-like 8 (ANGPTL8), also known as betatrophin, is known to regulate lipid metabolism. However, its mechanism of action remains elusive. METHODS: HepG2, 3T3-L1, and NIT-1 cells were cultured in amino acid-complete MEM or histidine-free MEM to detect ANGPTL8 expression. The three cell types were treated with or without recombinant ANGPTL8 to investigate its role in lipid metabolism. Hydrodynamic tail vein gene delivery was also used to examine the role of ANGPTL8 in mice. RESULTS: ANGPTL8 is significantly up-regulated in amino acid-deprived cultured cells in vitro. The activation of ANGPTL8 gene transcription was mediated through the RAS/c-RAF/MAPK signaling pathway rather than the general GCN2/ATF4 pathways. ANGPTL8 activated the ERK signal transduction pathway in hepatocytes, adipocytes, and pancreatic ß-cells, up-regulating early growth response transcription factor (Egr1) and down-regulating adipose triglyceride lipase (ATGL). CONCLUSION: ANGPTL8 is a stress-response protein that regulates fat metabolism by suppressing ATGL expression, revealing a mechanistic connection between ANGPTL8 and lipid homeostasis in mammalian cells.


Assuntos
Adipócitos/metabolismo , Angiopoietinas/genética , Lipase/genética , Triglicerídeos/metabolismo , Células 3T3-L1 , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismo , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Proteína 8 Semelhante a Angiopoietina , Proteínas Semelhantes a Angiopoietina , Angiopoietinas/metabolismo , Angiopoietinas/farmacologia , Animais , Diferenciação Celular , Linhagem Celular , Fator de Crescimento do Tecido Conjuntivo/genética , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Meios de Cultura/química , Meios de Cultura/farmacologia , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Regulação da Expressão Gênica , Glicerol/metabolismo , Células Hep G2 , Humanos , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Lipase/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-raf/genética , Proteínas Proto-Oncogênicas c-raf/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Transdução de Sinais , Proteínas ras/genética , Proteínas ras/metabolismo
7.
J Immunol ; 194(3): 1169-77, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25548220

RESUMO

Current evidence suggests that neonatal immunity is functionally distinct from adults. Although TLR signaling through the adaptor protein, MyD88, has been shown to be critical for survival to sepsis in adults, little is known about the role of MyD88 or TRIF in neonatal sepsis. We demonstrate that TRIF(-/-) but not MyD88(-/-) neonates are highly susceptible to Escherichia coli peritonitis and bacteremia. This was associated with decreased innate immune recruitment and function. Importantly, we found that the reverse was true in adults that MyD88(-/-) but not TRIF(-/-) or wild-type adults are susceptible to E. coli peritonitis and bacteremia. In addition, we demonstrate that TRIF but not MyD88 signaling is critical for the TLR4 protective adjuvant effect we have previously demonstrated. These data suggest a differential requirement for the survival of neonates versus adults to Gram-negative infection, and that modulation of TRIF in neonates can be used to augment survival to neonatal sepsis.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/genética , Infecções por Bactérias Gram-Negativas/genética , Infecções por Bactérias Gram-Negativas/imunologia , Imunidade Inata , Sepse/genética , Sepse/imunologia , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Animais Recém-Nascidos , Quimiocina CXCL10/metabolismo , Quimiocinas/biossíntese , Citocinas/biossíntese , Modelos Animais de Doenças , Suscetibilidade a Doenças/imunologia , Escherichia coli/imunologia , Feminino , Predisposição Genética para Doença , Infecções por Bactérias Gram-Negativas/metabolismo , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/mortalidade , Granulócitos/imunologia , Granulócitos/metabolismo , Interferon Tipo I/metabolismo , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Camundongos Knockout , Neutrófilos/imunologia , Neutrófilos/metabolismo , Fagocitose/genética , Fagocitose/imunologia , Espécies Reativas de Oxigênio/metabolismo , Sepse/metabolismo , Sepse/microbiologia , Sepse/mortalidade , Receptores Toll-Like/metabolismo
8.
Am J Physiol Endocrinol Metab ; 311(2): E530-41, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27436609

RESUMO

To better understand the role of irisin in humans, we examined the effects of irisin in human primary adipocytes and fresh human subcutaneous white adipose tissue (scWAT). Human primary adipocytes derived from 28 female donors' fresh scWAT were used to examine the effects of irisin on browning and mitochondrial respiration, and preadipocytes were used to examine the effects of irisin on adipogenesis and osteogenesis. Cultured fragments of scWAT and perirenal brown fat were used for investigating signal transduction pathways that mediate irisin's browning effect by Western blotting to detect phosphorylated forms of p38, ERK, and STAT3 as well as uncoupling protein 1 (UCP1). Individual responses to irisin in scWAT were correlated with basal expression levels of brown/beige genes. Irisin upregulated the expression of browning-associated genes and UCP1 protein in both cultured primary mature adipocytes and fresh adipose tissues. It also significantly increased thermogenesis at 5 nmol/l by elevating cellular energy metabolism (OCR and ECAR). Treating human scWAT with irisin increased UCP1 expression by activating the ERK and p38 MAPK signaling. Blocking either pathway with specific inhibitors abolished irisin-induced UCP1 upregulation. However, our results showed that UCP1 in human perirenal adipose tissue was insensitive to irisin. Basal levels of brown/beige and FNDC5 genes correlated positively with the browning response of scWAT to irisin. In addition, irisin significantly inhibited adipogenic differentiation but promoted osteogenic differentiation. We conclude that irisin promotes "browning" of mature white adipocytes by increasing cellular thermogenesis, whereas it inhibits adipogenesis and promotes osteogenesis during lineage-specific differentiation. Our findings provide a rationale for further exploring the therapeutic use of irisin in obesity and exercise-associated bone formation.


Assuntos
Adipócitos Brancos/efeitos dos fármacos , Adipogenia/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Fibronectinas/farmacologia , Mitocôndrias/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , RNA Mensageiro/efeitos dos fármacos , Termogênese/efeitos dos fármacos , Adipócitos Marrons/efeitos dos fármacos , Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Adipogenia/genética , Adolescente , Adulto , Idoso , Western Blotting , Respiração Celular/efeitos dos fármacos , Células Cultivadas , Exercício Físico , MAP Quinases Reguladas por Sinal Extracelular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Obesidade/metabolismo , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteogênese/genética , Fosfoproteínas/efeitos dos fármacos , Fosfoproteínas/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fator de Transcrição STAT3/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Gordura Subcutânea/citologia , Termogênese/genética , Proteína Desacopladora 1/efeitos dos fármacos , Proteína Desacopladora 1/metabolismo , Regulação para Cima , Adulto Jovem , Proteínas Quinases p38 Ativadas por Mitógeno/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
9.
Clin Immunol ; 172: 65-71, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27430519

RESUMO

The unusual subset of patients with severe hepatitis, hypergammaglobulinemia, arthritis, and LE cells in the blood reported by Henry Kunkel and others suggested to these investigators that "lupoid" hepatitis might share pathogenic mechanisms with SLE. More than half a century later, the etiology of autoimmune hepatitis remains unclear. The occurrence of autoimmune hepatitis in a small fraction (about 3%) of SLE patients in our lupus cohort and in two mouse models of SLE supports their conclusion that lupoid hepatitis may be share pathogenic mechanisms with SLE. The development of autoimmune hepatitis in mice with pristane-induced lupus provides an opportunity to further explore the potential link between these two autoimmune disorders.


Assuntos
Hepatite Autoimune , Lúpus Eritematoso Sistêmico , Actinas/imunologia , Adulto , Idoso , Animais , Autoanticorpos/sangue , Modelos Animais de Doenças , Feminino , Hepatite Autoimune/sangue , Hepatite Autoimune/imunologia , Hepatite Autoimune/patologia , Humanos , Imunoglobulina G/sangue , Fígado/patologia , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/induzido quimicamente , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/patologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Músculo Liso/imunologia , Soroglobulinas/análise , Terpenos , Adulto Jovem
11.
J Cell Sci ; 126(Pt 16): 3638-48, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23750005

RESUMO

Induced pluripotent stem cells (iPSCs) hold great promise for cell therapy. However, their low efficiency of lineage-specific differentiation and tumorigenesis severely hinder clinical translation. We hypothesized that reprogramming of somatic cells into lineage-specific progenitor cells might allow for large-scale expansion, avoiding the tumorigenesis inherent with iPSCs and simultaneously facilitating lineage-specific differentiation. Here we aimed at reprogramming rat hepatic WB cells, using four Yamanaka factors, into pancreatic progenitor cells (PPCs) or intermediate (IM) cells that have characteristics of PPCs. IM clones were selected based on their specific morphology and alkaline phosphatase activity and stably passaged under defined culture conditions. IM cells did not have iPSC properties, could be stably expanded in large quantity, and expressed all 14 genes that are used to define the PPC developmental stage. Directed differentiation of IM and WB cells by Pdx1-Ngn3-MafA (PNM) into pancreatic beta-like cells revealed that the IM cells are more susceptible to directed beta cell differentiation because of their open chromatin configuration, as demonstrated by expression of key pancreatic beta cell genes, secretion of insulin in response to glucose stimulation, and easy access to exogenous PNM proteins at the rat insulin 1 and Pdx1 promoters. This notion that IM cells are superior to their parental cells is further supported by the epigenetic demonstration of accessibility of Pdx1 and insulin 1 promoters. In conclusion, we have developed a strategy to derive and expand PPC cells from hepatic WB cells using conventional cell reprogramming. This proof-of-principal study may offer a novel, safe and effective way to generate autologous pancreatic beta cells for cell therapy of diabetes.


Assuntos
Hepatócitos/citologia , Células Secretoras de Insulina/citologia , Animais , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Células Cultivadas , Metilação de DNA , Hepatócitos/metabolismo , Proteínas de Homeodomínio/genética , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Regiões Promotoras Genéticas , Ratos , Células-Tronco/citologia , Células-Tronco/metabolismo , Transativadores/genética
12.
J Immunol ; 190(8): 3916-27, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23509349

RESUMO

Although ectopic lymphoid tissue formation is associated with many autoimmune diseases, it is unclear whether it serves a functional role in autoimmune responses. 2,6,10,14-Tetramethylpentadecane causes chronic peritoneal inflammation and lupus-like disease with autoantibody production and ectopic lymphoid tissue (lipogranuloma) formation. A novel transplantation model was used to show that transplanted lipogranulomas retain their lymphoid structure over a prolonged period in the absence of chronic peritoneal inflammation. Recipients of transplanted lipogranulomas produced anti-U1A autoantibodies derived exclusively from the donor, despite nearly complete repopulation of the transplanted lipogranulomas by host lymphocytes. The presence of ectopic lymphoid tissue alone was insufficient, as an anti-U1A response was not generated by the host in the absence of ongoing peritoneal inflammation. Donor-derived anti-U1A autoantibodies were produced for up to 2 mo by plasma cells/plasmablasts recruited to the ectopic lymphoid tissue by CXCR4. Although CD4(+) T cells were not required for autoantibody production from the transplanted lipogranulomas, de novo generation of anti-U1A plasma cells/plasmablasts was reduced following T cell depletion. Significantly, a population of memory B cells was identified in the bone marrow and spleen that did not produce anti-U1A autoantibodies unless stimulated by LPS to undergo terminal differentiation. We conclude that 2,6,10,14-tetramethylpentadecane promotes the T cell-dependent development of class-switched, autoreactive memory B cells and plasma cells/plasmablasts. The latter home to ectopic lymphoid tissue and continue to produce autoantibodies after transplantation and in the absence of peritoneal inflammation. However, peritoneal inflammation appears necessary to generate autoreactive B cells de novo.


Assuntos
Autoanticorpos/biossíntese , Subpopulações de Linfócitos B/imunologia , Células da Medula Óssea/imunologia , Memória Imunológica , Tecido Linfoide/imunologia , Plasmócitos/imunologia , Ribonucleoproteínas Nucleares Pequenas/imunologia , Animais , Autoanticorpos/metabolismo , Subpopulações de Linfócitos B/citologia , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Coristoma/imunologia , Feminino , Granuloma/sangue , Granuloma/imunologia , Granuloma/patologia , Tecido Linfoide/citologia , Tecido Linfoide/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Plasmócitos/metabolismo
13.
Clin Immunol ; 154(1): 49-65, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24971701

RESUMO

The onset of autoantibodies in systemic autoimmunity can be the result of a breakdown in tolerance at multiple checkpoints. Genetic, hormonal, and immunological factors can combine with environmental influences to accelerate the onset of disease and aggravate disease outcome. Here, we describe a novel mechanism relating to the regulatory role of Neutrophil Gelatinase Associated Lipocalin (NGAL) in modulating the levels of autoantibodies in pristane induced lupus. Following a single injection of pristane intraperitoneally, NGAL expression was induced in both the serum and spleen. Furthermore, NGAL deficient mice were more susceptible to the induction of pristane stimulated autoimmunity, and displayed higher numbers of autoantibody secreting cells and increased expression of activation induced cytidine deaminase (AID) and other inflammatory mediators in the spleen. In contrast, kidney damage was milder in NGAL deficient mice, indicating that NGAL was detrimental in autoantibody mediated kidney disease. These studies indicate that NGAL plays differential roles in different tissues in the context of lupus, and suggest a previously unrecognized role for NGAL in adaptive immunity.


Assuntos
Proteínas de Fase Aguda/imunologia , Autoanticorpos/sangue , Lipocalinas/imunologia , Lúpus Eritematoso Sistêmico/induzido quimicamente , Proteínas Proto-Oncogênicas/imunologia , Terpenos , Animais , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Imuno-Histoquímica , Interleucina-12/sangue , Rim/patologia , Lipocalina-2 , Lipocalinas/sangue , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas/sangue , Baço/enzimologia , Baço/metabolismo
14.
J Clin Immunol ; 34(2): 171-80, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24292724

RESUMO

PURPOSE: Anemia is one of the most common hematological manifestations in SLE patients, occurring in about 50% of active cases. STAT1 is a critical signaling molecule required for the production of type-1 interferon (I-IFN), CCL2, and CXCL10, all of which are upregulated in SLE. Overexpression of STAT1 has been described to be involved in anemia in animal models. The aim of this study is to analyze how these components are involved in SLE-associated anemia. METHODS: Blood samples were collected from 39 healthy donors and 101 SLE patients fulfilling ACR criteria. Samples were collected from a total of 180 visits (58 patients had 2 or more visits) of which 52 visits included a diagnosis of anemia. Healthy donors had only single visit. Total RNA, isolated from leukocytes, was analyzed by Taqman qPCR. Relative expression levels of I-IFN signature genes, chemokines, and miR-146a were determined by the ΔΔCT method. Results were correlated with clinical data and analyzed by the Wilcoxon/Kruskal-Wallis test and Fisher's exact test. RESULTS: Significant increases in IFN score (p < 0.0001), STAT1 (p < 0.0001), miR-146a (p < 0.0005), CCL2 (p = 0.0047), and CXCL10 (p = 0.017), as well as a significant decrease in pri-miR-146a (p = 0.0002), were detected in the anemic SLE patient visits (n = 52) compared to non-anemic SLE visits (n = 128). Regardless of disease activity, lupus nephritis, or race, anemic SLE patients displayed significantly elevated levels of STAT1 and miR-146a compared to non-anemic SLE patients. CONCLUSIONS: STAT1 and miR-146a may be upregulated during inflammation and via proinflammatory cytokines and chemokines in SLE. Prolonged upregulation of STAT1 and miR-146a appears to play an important role in anemia in SLE patients.


Assuntos
Anemia/etiologia , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/genética , MicroRNAs/genética , Fator de Transcrição STAT1/genética , Adulto , Fatores Etários , Anemia/complicações , Anemia/diagnóstico , Biomarcadores , Quimiocina CCL2/genética , Quimiocina CXCL10/genética , Feminino , Humanos , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/terapia , Nefrite Lúpica/complicações , Masculino , Pessoa de Meia-Idade , Grupos Populacionais/genética , Índice de Gravidade de Doença , Adulto Jovem
15.
J Immunol ; 188(8): 4113-21, 2012 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-22422888

RESUMO

Genetic polymorphisms of IFN regulatory factor 5 (IRF5) are associated with an increased risk of lupus in humans. In this study, we examined the role of IRF5 in the pathogenesis of pristane-induced lupus in mice. The pathological response to pristane in IRF5(-/-) mice shared many features with type I IFN receptor (IFNAR)(-/-) and TLR7(-/-) mice: production of anti-Sm/RNP autoantibodies, glomerulonephritis, generation of Ly6C(hi) monocytes, and IFN-I production all were greatly attenuated. Lymphocyte activation following pristane injection was greatly diminished in IRF5(-/-) mice, and Th cell differentiation was deviated from Th1 in wild-type mice toward Th2 in IRF5(-/-) mice. Th cell development was skewed similarly in TLR7(-/-) or IFNAR(-/-) mice, suggesting that IRF5 alters T cell activation and differentiation by affecting cytokine production. Indeed, production of IFN-I, IL-12, and IL-23 in response to pristane was markedly decreased, whereas IL-4 increased. Unexpectedly, plasmacytoid dendritic cells (pDC) were not recruited to the site of inflammation in IRF5(-/-) or MyD88(-/-) mice, but were recruited normally in IFNAR(-/-) and TLR7(-/-) mice. In striking contrast to wild-type mice, pristane did not stimulate local expression of CCL19 and CCL21 in IRF5(-/-) mice, suggesting that IRF5 regulates chemokine-mediated pDC migration independently of its effects on IFN-I. Collectively, these data indicate that altered production of IFN-I and other cytokines in IRF5(-/-) mice prevents pristane from inducing lupus pathology by broadly affecting T and B lymphocyte activation/differentiation. Additionally, we uncovered a new, IFN-I-independent role of IRF5 in regulating chemokines involved in the homing of pDCs and certain lymphocyte subsets.


Assuntos
Fatores Reguladores de Interferon/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Subpopulações de Linfócitos T/imunologia , Animais , Autoanticorpos/biossíntese , Autoanticorpos/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos B/patologia , Carcinógenos , Diferenciação Celular/imunologia , Movimento Celular/imunologia , Citocinas/biossíntese , Citocinas/imunologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Modelos Animais de Doenças , Humanos , Fatores Reguladores de Interferon/deficiência , Fatores Reguladores de Interferon/genética , Lúpus Eritematoso Sistêmico/induzido quimicamente , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/patologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia , Terpenos , Equilíbrio Th1-Th2
16.
Arthritis Rheumatol ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38923837

RESUMO

OBJECTIVE: About 3% of patients with lupus develop severe diffuse alveolar hemorrhage (DAH) with pulmonary vasculitis. C57BL/6 (B6) mice with pristane-induced lupus also develop DAH, but BALB/c mice are resistant. DAH is independent of Toll-like receptor signaling and other inflammatory pathways. This study examined the role of the MEK1/2 pathway (MEK1/2-ERK1/2, JNK, p38). METHODS: B6 and BALB/c mice were treated with pristane with or without inhibitors of MEK1/2 (trametinib/GSK1120212 [GSK]), ERK1/2 (SCH772984 [SCH]), JNK, or p38. Effects on lung hemorrhage and hemostasis were determined. RESULTS: GSK and SCH abolished DAH, whereas JNK and p38 inhibitors were ineffective. Apoptotic cells were present in lung samples from pristane-treated mice but not in mice receiving pristane and GSK, and endothelial dysfunction was normalized. Expression of the ERK1/2-regulated transcription factor early growth response 1 increased in pristane-treated B6, but not BALB/c, mice and was normalized by GSK. Pristane also increased expression of the anticoagulant genes Tfpi and Thbd in B6 mice. The ratio of Tfpi to tissue factor (F3) to Tfpi increased in B6 (but not BALB/c) mice and was normalized by GSK. Circulating thrombomodulin protein levels increased in B6 mice and returned to normal after GSK treatment. Consistent with augmented endothelial anticoagulant activity, pristane treatment increased tail bleeding in B6 mice. CONCLUSION: Pristane treatment promotes lung endothelial injury and DAH in B6 mice by activating the MEK1/2-ERK1/2 pathway and impairing hemostasis. The hereditary factors determining susceptibility to lung injury and bleeding in pristane-induced lupus are relevant to the pathophysiology of life-threatening DAH in systemic lupus erythematosus and may help to optimize therapy.

17.
bioRxiv ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38766226

RESUMO

Objective: About 3% of lupus patients develop severe diffuse alveolar hemorrhage (DAH) with pulmonary vasculitis. B6 mice with pristane-induced lupus also develop DAH, but BALB/c mice are resistant. DAH is independent of TLR signaling and other inflammatory pathways. This study examined the role of the mitogen-activated protein kinase pathway (MEK1/2-ERK1/2, JNK, p38). Methods: B6 and BALB/c mice were treated with pristane ± inhibitors of MEK1/2 (trametinib/GSK1120212, "GSK"), ERK1/2 (SCH772984, "SCH"), JNK, or p38. Effects on lung hemorrhage and hemostasis were determined. Results: GSK and SCH abolished DAH, whereas JNK and p38 inhibitors were ineffective. Apoptotic cells were present in lung from pristane-treated mice, but not mice receiving pristane+GSK and endothelial dysfunction was normalized. Expression of the ERK1/2-regulated transcription factor Egr1 increased in pristane-treated B6, but not BALB/c, mice and was normalized by GSK. Pristane also increased expression of the anticoagulant genes Tfpi (tissue factor pathway inhibitor) and Thbd (thrombomodulin) in B6 mice. The ratio of tissue factor ( F3 ) to Tfpi increased in B6 (but not BALB/c) mice and was normalized by GSK. Circulating Thbd protein increased in B6 mice and returned to normal after GSK treatment. Consistent with augmented endothelial anticoagulant activity, pristane treatment increased tail bleeding in B6 mice. Conclusion: Pristane treatment promotes lung endothelial injury and DAH in B6 mice by activating the MEK1/2-ERK1/2 pathway and impairing hemostasis. The hereditary factors determining susceptibility to lung injury and bleeding in pristane-induced lupus are relevant to the pathophysiology of life-threatening DAH in SLE and may help to optimize therapy.

18.
J Immunol ; 186(3): 1747-54, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21191074

RESUMO

Exposure to naturally occurring hydrocarbon oils is associated with the development of chronic inflammation and a wide spectrum of pathological findings in humans and animal models. The mechanism underlying the unremitting inflammatory response to hydrocarbons remains largely unclear. The medium-length alkane 2,6,10,14 tetramethylpentadecane (also known as pristane) is a hydrocarbon that potently elicits chronic peritonitis characterized by persistent infiltration of neutrophils and monocytes. In this study, we reveal the essential role of IL-1α in sustaining the chronic recruitment of neutrophils following 2,6,10,14 tetramethylpentadecane treatment. IL-1α and IL-1R signaling promote the migration of neutrophils to the peritoneal cavity in a CXCR2-dependent manner. This mechanism is at least partially dependent on the production of the neutrophil chemoattractant CXCL5. Moreover, although chronic infiltration of inflammatory monocytes is dependent on a different pathway requiring TLR-7, type I IFN receptor, and CCR2, the adaptor molecules MyD88, IL-1R-associated kinase (IRAK)-4, IRAK-1, and IRAK-2 are shared in regulating the recruitment of both monocytes and neutrophils. Taken together, our findings uncover an IL-1α-dependent mechanism of neutrophil recruitment in hydrocarbon-induced peritonitis and illustrate the interactions of innate immune pathways in chronic inflammation.


Assuntos
Hidrocarbonetos/farmacologia , Mediadores da Inflamação/farmacologia , Interleucina-1alfa/fisiologia , Infiltração de Neutrófilos/imunologia , Óleos/farmacologia , Picolinas/farmacologia , Animais , Doença Crônica , Inflamação/induzido quimicamente , Inflamação/imunologia , Inflamação/patologia , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Knockout , Células NIH 3T3 , Infiltração de Neutrófilos/efeitos dos fármacos , Receptores de Interleucina-1/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia
19.
Eur J Immunol ; 41(7): 2029-39, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21469088

RESUMO

MicroRNAs (miRNAs), small non-coding RNA molecules that post-transcriptionally regulate gene expression, are known to play key roles in regulating immune responses and autoimmunity. We investigated miR-146a expression in Sjögren's syndrome (SjS) patients as well as in the SjS-prone C57BL/6.NOD-Aec1Aec2 mouse model, to elucidate its involvement in SjS pathogenesis. Expression of miR-146a was examined in the PBMCs of 25 SjS patients and ten healthy donors, as well as in PBMCs, salivary and lacrimal glands of SjS-prone mice and WT C57BL/6J mice. Functional assays using THP-1 human monocytes were conducted to determine the biological roles of miR-146a in innate immunity. Expression of miR-146a was significantly increased in SjS patients compared with healthy controls, and was upregulated in the salivary glands and PBMCs of the SjS-prone mouse at both 8 wk (prior to disease onset) and 20 wk (full-blown disease) of age. More importantly, functional analysis revealed roles for miR-146a in increasing phagocytic activity and suppressing inflammatory cytokine production while migration, nitric oxide production and expression of antigen-presenting/costimulatory molecules are not affected in human monocytic THP-1 cells. Taken together, our data suggest that abnormal expression/regulation of microRNAs in innate immunity may contribute to, or be indicative of, the initiation and progression of SjS.


Assuntos
Imunidade Inata , MicroRNAs/metabolismo , Síndrome de Sjogren/genética , Síndrome de Sjogren/imunologia , Adulto , Idoso , Animais , Apresentação de Antígeno , Quimiotaxia de Leucócito , Citocinas/biossíntese , Feminino , Expressão Gênica , Regulação da Expressão Gênica , Inativação Gênica , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , MicroRNAs/genética , Pessoa de Meia-Idade , Monócitos/imunologia , Óxido Nítrico/biossíntese , Fagocitose , Reação em Cadeia da Polimerase , Glândulas Salivares/citologia , Glândulas Salivares/metabolismo , Transdução de Sinais/genética , Síndrome de Sjogren/metabolismo , Adulto Jovem
20.
Trends Immunol ; 30(9): 455-64, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19699150

RESUMO

Tetramethylpentadecane (TMPD, or commonly known as pristane)-induced lupus is a murine model of systemic lupus erythematosus (SLE). Renal disease and autoantibody production strictly depend on signaling through the interferon (IFN)-I receptor. The major source of IFN-I is immature monocytes bearing high levels of the surface marker Ly6C. Interferon production is mediated exclusively by signaling through TLR7 and the adapter protein MyD88. It is likely that endogenous TLR7 ligands such as components of small nuclear ribonucleoprotein complexes are involved in triggering disease. Lupus autoantibodies are produced in ectopic lymphoid tissue developing in response to TMPD. This model is well suited for examining links between dysregulated IFN-I production and the pathogenesis of human SLE, which like TMPD-lupus, is associated with high levels of IFN-I.


Assuntos
Autoanticorpos/imunologia , Interferon Tipo I/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Terpenos/imunologia , Proteínas Centrais de snRNP/imunologia , Animais , Modelos Animais de Doenças , Humanos , Interferon Tipo I/metabolismo , Lúpus Eritematoso Sistêmico/induzido quimicamente , Camundongos , Transdução de Sinais/imunologia
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