Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
PLoS One ; 15(7): e0236664, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32722684

RESUMO

BACKGROUND: Systemic lupus erythematosus (SLE) is a severe autoimmune disease in which immune tolerance defects drive production of pathogenic anti-nuclear autoantibodies. Anergic B cells are considered a potential source of these autoantibodies due to their autoreactivity and overrepresentation in SLE patients. Studies of lupus-prone mice have shown that genetic defects mediating autoimmunity can breach B cell anergy, but how this breach occurs with regards to endogenous nuclear antigen remains unclear. We investigated whether B and T cell defects in congenic mice (c1) derived from the lupus-prone New Zealand Black strain can breach tolerance to nuclear self-antigen in the presence of knock-in genes (Vκ8/3H9; dKI) that generate a ssDNA-reactive, anergic B cell population. METHODS: Flow cytometry was used to assess splenic B and T cells from 8-month-old c1 dKI mice and serum autoantibodies were measured by ELISA. dKI B cells stimulated in vitro with anti-IgM were assessed for proliferation and activation by examining CFSE decay and CD86. Cytokine-producing T cells were identified by flow cytometry following culture of dKI splenocytes with PMA and ionomycin. dKI B cells from 6-8-week-old mice were adoptively transferred into 4-month-old wild type recipients and assessed after 7 days via flow cytometry and immunofluorescence microscopy. RESULTS: c1 dKI mice exhibited B cell proliferation indicative of impaired anergy, but had attenuated autoantibodies and germinal centres compared to wild type littermates. This attenuation appeared to stem from a decrease in PD-1hi T helper cells in the dKI strains, as c1 dKI B cells were recruited to germinal centres when adoptively transferred into c1 wild type mice. CONCLUSION: Anergic, DNA-specific autoreactive B cells only seem to drive profound autoimmunity in the presence of concomitant defects in the T cell subsets that support high-affinity plasma cell production.


Assuntos
Anticorpos Antinucleares/genética , Anticorpos Antifosfolipídeos/genética , Antígenos/imunologia , Linfócitos B/imunologia , Anergia Clonal , Lúpus Eritematoso Sistêmico/imunologia , Animais , Linfócitos B/citologia , Proliferação de Células , DNA de Cadeia Simples/imunologia , Suscetibilidade a Doenças , Técnicas de Introdução de Genes , Lúpus Eritematoso Sistêmico/genética , Camundongos
2.
Arthritis Care Res (Hoboken) ; 72(12): 1809-1819, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31628718

RESUMO

OBJECTIVE: Screening for cognitive impairment in systemic lupus erythematosus (SLE) conventionally relies on the American College of Rheumatology (ACR) neuropsychologic battery (NB), which is not universally available. To develop a more accessible screening approach, we assessed validity of the Automated Neuropsychological Assessment Metrics (ANAM). Using the ACR NB as the gold standard for cognitive impairment classification, the objectives were 1) to measure overall discriminative validity of the ANAM for cognitive impairment versus no cognitive impairment, 2) to identify ANAM subtests and scores that best differentiate patients with cognitive impairment from those with no cognitive impairment, and 3) to derive ANAM composite indices and cutoffs. METHODS: A total of 211 consecutive adult patients, female and male, with SLE were administered the ANAM and ACR NB. 1) For overall discriminative validity of the ANAM, we compared patients with cognitive impairment versus those with no cognitive impairment on 4 scores. 2) Six ANAM models using different scores were developed, and the most discriminatory subtests were selected using logistic regression analyses. The area under the receiver operating characteristic curve (AUC) was calculated to establish ANAM validity against the ACR NB. 3) ANAM composite indices and cutoffs were derived for the best models, and sensitivities and specificities were calculated. RESULTS: Patients with no cognitive impairment performed better on most ANAM subtests, supporting ANAM's discriminative validity. Cognitive impairment could be accurately identified by selected ANAM subtests with top models, demonstrating excellent AUCs of 81% and 84%. Derived composite indices and cutoffs demonstrated sensitivity of 78-80% and specificity of 70%. CONCLUSION: This study provides support for ANAM's discriminative validity for cognitive impairment and utility for cognitive screening in adult SLE. Derived composite indices and cutoffs enhance clinical applicability.

3.
Semin Arthritis Rheum ; 50(1): 84-94, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31303437

RESUMO

OBJECTIVES: To systematically review and synthesize literature on 1) the overall prevalence of depression and anxiety in SLE patients in identified studies, and 2) the pooled prevalence per metrics of depression and anxiety in adult SLE patients. METHODS: This review used (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) PRISMA guidelines and in-depth searches in four databases (1954-2016; Ovid-based Medline, Embase, PsycINFO and CINAHL) to identify articles on the prevalence of depression and/or anxiety in adult SLE patients. Included studies were critically appraised and analyzed. The prevalence of depression and anxiety was studied for all included studies, and whenever possible, pooled prevalence (PP) was determined for more commonly used metrics. Statistical and publication bias was assessed using funnel plots. RESULT: A total of 3103 references were identified, 226 were selected for detailed review and 72 were included in the final analysis. OVERALL PREVALENCE: The depression PP, obtained from 69 studies representing 23,386 SLE patients, was 35.0% (95% CI: 29.9%-40.3%). The anxiety PP, obtained from 38 studies representing 4439 SLE patients, was 25.8% (95% CI: 19.2%-32.9%). PREVALENCE PER METRICS USED: The more commonly used instruments included the Centre for Epidemiological Studies - Depression (CES-D), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Hospital Anxiety and Depression Scales (HADS-A/D), and Hamilton Rating Scales for Depression/Anxiety (HAM-D/A)]. The CES-D was utilized in 13 studies including 1856 SLE patients; depression PP was 41.5% (95% CI: 35.1%-48.1%). The BDI was utilized in 14 studies including 1355 SLE patients and the BAI in 3 studies including 489 patients; depression PP was 39.9% (95% CI: 31.1%-49.1) and anxiety PP was 38.4% (95% CI: 34.2%-42.8%). The HADS-D was utilized in 14 studies including 1238 SLE patients and the HADS-A in 12 studies including 1099 patients respectively; its depression PP was 24.4% (95% CI: 19.1%-30.1%) and anxiety PP was 38.3% (95% CI: 29.1%-47.9%). The HAM-D was utilized in 4 studies including 267 SLE patients and the HAM-A in 4 studies including 213 patients respectively; its depression PP was 40.0% (95% CI: 23.0%-59.0%) and anxiety PP was 39.0% (95% CI: 32.0%-45.0%). CONCLUSION: There was high variability in the prevalence of depression and anxiety, ranging from 8.7%-78.6% and 1.1%-71.4%, respectively. This could be attributed to the lack of consistency in the metrics used and its definition for depression and anxiety in SLE. Studies that used a specific metric, such as the CES-D, BDI or HAM-D, yielded similar depression prevalence. The HADS-D had the lowest prevalence. All metrics of anxiety yielded similar anxiety prevalence.

4.
Rheumatology (Oxford) ; 59(1): 90-98, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31236574

RESUMO

OBJECTIVE: LN is one of the most common and severe manifestations of SLE. Our aim was to test the association of SLE risk loci with LN risk in childhood-onset SLE (cSLE) and adult-onset SLE (aSLE). METHODS: Two Toronto-based tertiary care SLE cohorts included cSLE (diagnosed <18 years) and aSLE patients (diagnosed ⩾18 years). Patients met ACR and/or SLICC SLE criteria and were genotyped on the Illumina Multi-Ethnic Global Array or Omni1-Quad arrays. We identified those with and without biopsy-confirmed LN. HLA and non-HLA additive SLE risk-weighted genetic risk scores (GRSs) were tested for association with LN risk in logistic models, stratified by cSLE/aSLE and ancestry. Stratified effect estimates were meta-analysed. RESULTS: Of 1237 participants, 572 had cSLE (41% with LN) and 665 had aSLE (30% with LN). Increasing non-HLA GRS was significantly associated with increased LN risk [odds ratio (OR) = 1.26; 95% CI 1.09, 1.46; P = 0.0006], as was increasing HLA GRS in Europeans (OR = 1.55; 95% CI 1.07, 2.25; P = 0.03). There was a trend for stronger associations between both GRSs and LN risk in Europeans with cSLE compared with aSLE. When restricting cases to proliferative LN, the magnitude of these associations increased for both the non-HLA (OR = 1.30; 95% CI 1.10, 1.52; P = 0.002) and HLA GRS (OR = 1.99; 95% CI 1.29, 3.08; P = 0.002). CONCLUSION: We observed an association between known SLE risk loci and LN risk in children and adults with SLE, with the strongest effect observed among Europeans with cSLE. Future studies will include SLE-risk single nucleotide polymorphisms specific to non-European ancestral groups and validate findings in an independent cohort.


Assuntos
Idade de Início , Loci Gênicos/genética , Predisposição Genética para Doença/genética , Lúpus Eritematoso Sistêmico/genética , Nefrite Lúpica/genética , Adolescente , Adulto , Criança , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Predisposição Genética para Doença/etnologia , Genótipo , Humanos , Modelos Logísticos , Lúpus Eritematoso Sistêmico/etnologia , Nefrite Lúpica/etnologia , Masculino , Razão de Chances , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , Adulto Jovem
5.
Sci Adv ; 4(11): eaar7653, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30417091

RESUMO

Memory B cells and plasma cells are antigen-experienced cells tasked with the maintenance of humoral protection. Despite these prominent functions, definitive cell surface markers have not been identified for these cells. We report here the isolation and characterization of the monoclonal variable lymphocyte receptor B (VLRB) N8 antibody from the evolutionarily distant sea lamprey that specifically recognizes memory B cells and plasma cells in humans. Unexpectedly, we determined that VLRB N8 recognizes the human leukocyte antigen-I (HLA-I) antigen in a tyrosine sulfation-dependent manner. Furthermore, we observed increased binding of VLRB N8 to memory B cells in individuals with autoimmune disorders multiple sclerosis and systemic lupus erythematosus. Our study indicates that lamprey VLR antibodies uniquely recognize a memory B cell- and plasma cell-specific posttranslational modification of HLA-I, the expression of which is up-regulated during B cell activation.


Assuntos
Anticorpos Monoclonais/imunologia , Linfócitos B/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Memória Imunológica/imunologia , Plasmócitos/imunologia , Receptores de Antígenos/imunologia , Tirosina/análogos & derivados , Animais , Anticorpos Monoclonais/sangue , Linfócitos B/metabolismo , Células Cultivadas , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Região Variável de Imunoglobulina/imunologia , Região Variável de Imunoglobulina/metabolismo , Lampreias/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/metabolismo , Esclerose Múltipla/imunologia , Esclerose Múltipla/metabolismo , Plasmócitos/metabolismo , Receptores de Antígenos/metabolismo , Tirosina/química
6.
PLoS One ; 13(5): e0196117, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29742110

RESUMO

Both a lack of biomarkers and relatively ineffective treatments constitute impediments to management of lupus nephritis (LN). Here we used gene expression microarrays to contrast the transcriptomic profiles of active SLE patients with and without LN to identify potential biomarkers for this condition. RNA isolated from whole peripheral blood of active SLE patients was used for transcriptomic profiling and the data analyzed by linear modeling, with corrections for multiple testing. Results were validated in a second cohort of SLE patients, using NanoString technology. The majority of genes demonstrating altered transcript abundance between patients with and without LN were neutrophil-related. Findings in the validation cohort confirmed this observation and showed that levels of RNA abundance in renal remission were similar to active patients without LN. In secondary analyses, RNA abundance correlated with disease activity, hematuria and proteinuria, but not renal biopsy changes. As abundance levels of the individual transcripts correlated strongly with each other, a composite neutrophil score was generated by summing all levels before examining additional correlations. There was a modest correlation between the neutrophil score and the blood neutrophil count, which was largely driven by the dose of glucocorticosteroids and not the proportion of low density and/or activated neutrophils. Analysis of longitudinal data revealed no correlation between baseline neutrophil score or changes over the first year of follow-up with subsequent renal flare or treatment outcomes, respectively. The findings argue that although the neutrophil score is associated with LN, its clinical utility as a biomarker may be limited.


Assuntos
Perfilação da Expressão Gênica , Nefrite Lúpica/genética , Nefrite Lúpica/imunologia , Neutrófilos/metabolismo , Adulto , Contagem de Células , Feminino , Humanos , Interferons/farmacologia , Nefrite Lúpica/etiologia , Masculino , Pessoa de Meia-Idade , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Adulto Jovem
7.
J Immunol Methods ; 457: 33-40, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29614266

RESUMO

Genome editing in human cells with targeted nucleases now enables diverse experimental and therapeutic genome engineering applications, but extension to primary human B cells remains limited. Here we report a method for targeted genetic engineering in primary human B cells, utilizing electroporation of CRISPR-Cas9 ribonucleoproteins (RNPs) to introduce gene knockout mutations at protein-coding loci with high efficiencies that in some cases exceeded 80%. Further, we demonstrate knock-in editing of targeted nucleotides with efficiency exceeding 10% through co-delivery of oligonucleotide templates for homology directed repair. We delivered Cas9 RNPs in two distinct in vitro culture systems to achieve editing in both undifferentiated B cells and activated B cells undergoing differentiation, reflecting utility in diverse experimental conditions. In summary, we demonstrate a powerful and scalable research tool for functional genetic studies of human B cell biology that may have further applications in engineered B cell therapeutics.


Assuntos
Linfócitos B/citologia , Sistemas CRISPR-Cas , Engenharia Genética , Ribonucleoproteínas/genética , Adolescente , Adulto , Linfócitos B/imunologia , Linhagem Celular , Técnicas de Inativação de Genes , Humanos , Mutação , Tonsila Palatina/citologia , Reparo de DNA por Recombinação , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Adulto Jovem
8.
PLoS One ; 12(6): e0179506, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28628673

RESUMO

Lupus is characterized by a loss of B cell tolerance leading to autoantibody production. In this study, we explored the mechanisms underlying this loss of tolerance using B6 congenic mice with an interval from New Zealand Black chromosome 1 (denoted c1(96-100)) sufficient for anti-nuclear antibody production. Transgenes for soluble hen egg white lysozyme (sHEL) and anti-HEL immunoglobulin were crossed onto this background and various tolerance mechanisms examined. We found that c1(96-100) mice produced increased levels of IgM and IgG anti-HEL antibodies compared to B6 mice and had higher proportions of germinal center B cells and long-lived plasma cells, suggesting a germinal center-dependent breach of B cell anergy. Consistent with impaired anergy induction, c1(96-100) double transgenic B cells showed enhanced survival and CD86 upregulation. Hematopoietic chimeric sHEL mice with a mixture of B6 and c1(96-100) HEL transgenic B cells recapitulated these results, suggesting the presence of a B cell autonomous defect. Surprisingly, however, there was equivalent recruitment of B6 and c1(96-100) B cells into germinal centers and differentiation to splenic plasmablasts in these mice. In contrast, there were increased proportions of c1(96-100) T follicular helper cells and long-lived plasma cells as compared to their B6 counterparts, suggesting that both B and T cell defects are required to breach germinal center tolerance in this model. This possibility was further supported by experiments showing an enhanced breach of anergy in double transgenic mice with a longer chromosome 1 interval with additional T cell defects.


Assuntos
Linfócitos B/metabolismo , Cromossomos/genética , Tolerância Imunológica , Animais , Apoptose , Linfócitos B/citologia , Linfócitos B/imunologia , Antígeno B7-2/metabolismo , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular , Galinhas , Cromossomos/metabolismo , Imunoglobulinas/genética , Imunoglobulinas/metabolismo , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia de Fluorescência , Muramidase/genética , Muramidase/metabolismo , Nova Zelândia , Fosfatidilinositol 3-Quinases/metabolismo , Baço/metabolismo , Baço/patologia , Regulação para Cima
9.
J Immunol ; 198(10): 3949-3962, 2017 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-28373584

RESUMO

Invariant NKT (iNKT) cells are innate lymphocytes that respond to glycolipids presented by the MHC class Ib molecule CD1d and are rapidly activated to produce large quantities of cytokines and chemokines. iNKT cell development uniquely depends on interactions between double-positive thymocytes that provide key homotypic interactions between signaling lymphocyte activation molecule (SLAM) family members. However, the role of SLAM receptors in the differentiation of iNKT cell effector subsets and activation has not been explored. In this article, we show that C57BL/6 mice containing the New Zealand Black Slam locus have profound alterations in Ly108, CD150, and Ly9 expression that is associated with iNKT cell hyporesponsiveness. This loss of function was only apparent when dendritic cells and iNKT cells had a loss of SLAM receptor expression. Using small interfering RNA knockdowns and peptide-blocking strategies, we demonstrated that trans-Ly108 interactions between dendritic cells and iNKT cells are critical for robust activation. LY108 costimulation similarly increased human iNKT cell activation. Thus, in addition to its established role in iNKT cell ontogeny, Ly108 regulates iNKT cell function in mice and humans.


Assuntos
Antígenos Ly/metabolismo , Células Dendríticas/metabolismo , Ativação Linfocitária , Células T Matadoras Naturais/imunologia , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Animais , Antígenos CD1d/imunologia , Antígenos Ly/genética , Antígenos Ly/imunologia , Diferenciação Celular , Citocinas/biossíntese , Citocinas/imunologia , Células Dendríticas/imunologia , Regulação da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Células T Matadoras Naturais/metabolismo , RNA Interferente Pequeno , Família de Moléculas de Sinalização da Ativação Linfocitária/deficiência , Família de Moléculas de Sinalização da Ativação Linfocitária/genética , Família de Moléculas de Sinalização da Ativação Linfocitária/imunologia , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária/genética , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária/imunologia
10.
J Rheumatol ; 44(1): 18-23, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27803141

RESUMO

OBJECTIVE: Case ascertainment through self-report is a convenient but often inaccurate method to collect information. The purposes of this study were to develop, assess the sensibility, and validate a tool to identify cases of systemic autoimmune rheumatic diseases (SARD) in the outpatient setting. METHODS: The SARD tool was administered to subjects sampled from specialty clinics. Determinants of sensibility - comprehensibility, feasibility, validity, and acceptability - were evaluated using a numeric rating scale from 1-7. Comprehensibility was evaluated using the Flesch Reading Ease and the Flesch-Kincaid Grade Level. Self-reported diagnoses were validated against medical records using Cohen's κ statistic. RESULTS: There were 141 participants [systemic lupus erythematosus (SLE), systemic sclerosis (SSc), rheumatoid arthritis, Sjögren syndrome (SS), inflammatory myositis (polymyositis/dermatomyositis; PM/DM), and controls] who completed the questionnaire. The Flesch Reading Ease score was 77.1 and the Flesch-Kincaid Grade Level was 4.4. Respondents endorsed (mean ± SD) comprehensibility (6.12 ± 0.92), feasibility (5.94 ± 0.81), validity (5.35 ± 1.10), and acceptability (3.10 ± 2.03). The SARD tool had a sensitivity of 0.91 (95% CI 0.88-0.94) and a specificity of 0.99 (95% CI 0.96-1.00). The agreement between the SARD tool and medical record was κ = 0.82 (95% CI 0.77-0.88). Subgroup analysis by SARD found κ coefficients for SLE to be κ = 0.88 (95% CI 0.79-0.97), SSc κ = 1.0 (95% CI 1.0-1.0), PM/DM κ = 0.72 (95% CI 0.49-0.95), and SS κ = 0.85 (95% CI 0.71-0.99). The screening questions had sensitivity ranging from 0.96 to 1.0 and specificity ranging from 0.88 to 1.0. CONCLUSION: This SARD case ascertainment tool has demonstrable sensibility and validity. The use of both screening and confirmatory questions confers added accuracy.


Assuntos
Doenças Autoimunes/diagnóstico , Doenças Reumáticas/diagnóstico , Inquéritos e Questionários , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
11.
PLoS One ; 11(3): e0150515, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26964093

RESUMO

The development and progression of systemic lupus erythematosus is mediated by the complex interaction of genetic and environmental factors. To decipher the genetics that contribute to pathogenesis and the production of pathogenic autoantibodies, our lab has focused on the generation of congenic lupus-prone mice derived from the New Zealand Black (NZB) strain. Previous work has shown that an NZB-derived chromosome 4 interval spanning 32 to 151 Mb led to expansion of CD5+ B and Natural Killer T (NKT) cells, and could suppress autoimmunity when crossed with a lupus-prone mouse strain. Subsequently, it was shown that CD5+ B cells but not NKT cells derived from these mice could suppress the development of pro-inflammatory T cells. In this paper, we aimed to further resolve the genetics that leads to expansion of these two innate-like populations through the creation of additional sub-congenic mice and to characterize the role of IL-10 in the suppression of autoimmunity through the generation of IL-10 knockout mice. We show that expansion of CD5+ B cells and NKT cells localizes to a chromosome 4 interval spanning 91 to 123 Mb, which is distinct from the region that mediates the majority of the suppressive phenotype. We also demonstrate that IL-10 is critical to restraining autoantibody production and surprisingly plays a vital role in supporting the expansion of innate-like populations.


Assuntos
Autoanticorpos/imunologia , Linfócitos B/imunologia , Antígenos CD5 , Interleucina-10 , Lúpus Eritematoso Sistêmico , Células T Matadoras Naturais/imunologia , Animais , Linfócitos B/patologia , Cromossomos de Mamíferos/genética , Cromossomos de Mamíferos/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/patologia , Camundongos Endogâmicos NZB , Camundongos Knockout , Células T Matadoras Naturais/patologia
12.
J Rheumatol ; 42(12): 2318-26, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26568589

RESUMO

OBJECTIVE: Serologically active clinically quiescent (SACQ) patients with systemic lupus erythematosus (SLE) remain clinically quiescent for prolonged periods despite anti-dsDNA antibodies and/or low complements, indicating the presence of immune complexes. The immune mechanisms leading to this quiescence are unknown. However, in addition to activating complement, immune complex uptake by various cells leads to the production of interferon (IFN)-α and other proinflammatory factors that are also involved in tissue damage. Here we investigate whether production of these factors is reduced in SACQ patients. METHODS: The levels of 5 IFN-induced genes and 19 cyto/chemokines were measured in SACQ patients and were compared with those in serologically and clinically active (SACA) and serologically and clinically quiescent (SQCQ) patients. SACQ and SQCQ were defined as ≥ 2 years without clinical activity, with/without persistent serologic activity, respectively, and off corticosteroids/immunosuppressives. SACA was defined as disease activity compelling immunosuppression. Levels of OAS1, IFIT1, MX1, LY6E, and ISG15 were measured by quantitative real-time polymerase chain reaction (PCR) and a composite score (IFN-5) derived from this. Plasma cyto/chemokines were measured by Luminex assay. Nonparametric univariate and logistic regression analyses were conducted. RESULTS: There were no differences in gene expression or cyto/chemokine levels between SACQ and SQCQ patients. The SACQ IFN-5 score was significantly lower than that of SACA (p = 0.003) and was driven by SACQ status, not by autoantibody profile or disease duration. Levels of granulocyte-macrophage colony-stimulating factor, interleukin (IL) 6, IL-10, IFN-γ-inducible protein 10, monocyte chemoattractant protein 1, and tumor necrosis factor-α were significantly lower in SACQ than SACA. CONCLUSION: The levels of proinflammatory factors in SACQ mirror those of SQCQ patients, indicating reduced production of these factors despite the presence of immune complexes.


Assuntos
Citocinas/sangue , Interferons/sangue , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/fisiopatologia , Adolescente , Adulto , Biomarcadores/sangue , Quimiocinas/sangue , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Modelos Logísticos , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Masculino , Monitorização Fisiológica , Análise Multivariada , Pacientes Ambulatoriais/estatística & dados numéricos , Prognóstico , Estudos Prospectivos , Medição de Risco , Testes Sorológicos , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Adulto Jovem
13.
Nat Genet ; 47(12): 1457-1464, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26502338

RESUMO

Systemic lupus erythematosus (SLE) is a genetically complex autoimmune disease characterized by loss of immune tolerance to nuclear and cell surface antigens. Previous genome-wide association studies (GWAS) had modest sample sizes, reducing their scope and reliability. Our study comprised 7,219 cases and 15,991 controls of European ancestry, constituting a new GWAS, a meta-analysis with a published GWAS and a replication study. We have mapped 43 susceptibility loci, including ten new associations. Assisted by dense genome coverage, imputation provided evidence for missense variants underpinning associations in eight genes. Other likely causal genes were established by examining associated alleles for cis-acting eQTL effects in a range of ex vivo immune cells. We found an over-representation (n = 16) of transcription factors among SLE susceptibility genes. This finding supports the view that aberrantly regulated gene expression networks in multiple cell types in both the innate and adaptive immune response contribute to the risk of developing SLE.


Assuntos
Imunidade Adaptativa/genética , Regulação da Expressão Gênica , Estudos de Associação Genética , Marcadores Genéticos/genética , Imunidade Inata/genética , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/patologia , Estudos de Casos e Controles , Loci Gênicos , Predisposição Genética para Doença , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Metanálise como Assunto , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco
14.
J Immunol ; 195(10): 4623-31, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26432891

RESUMO

We showed previously that C57BL/6 congenic mice with an introgressed homozygous 70 cM (125.6 Mb) to 100 cM (179.8 Mb) interval on c1 from the lupus-prone New Zealand Black (NZB) mouse develop high titers of antinuclear Abs and severe glomerulonephritis. Using subcongenic mice, we found that a genetic locus in the 88-96 cM region was associated with altered dendritic cell (DC) function and synergized with T cell functional defects to promote expansion of pathogenic proinflammatory T cell subsets. In this article, we show that the promoter region of the NZB gene encoding the SLAM signaling pathway adapter molecule EWS-activated transcript 2 (EAT-2) is polymorphic, which results in an ∼ 70% reduction in EAT-2 in DC. Silencing of the EAT-2 gene in DC that lacked this polymorphism led to increased production of IL-12 and enhanced differentiation of T cells to a Th1 phenotype in T cell-DC cocultures, reproducing the phenotype observed for DC from congenic mice with the NZB c1 70-100 cM interval. SLAM signaling was shown to inhibit production of IL-12 by CD40L-activated DCs. Consistent with a role for EAT-2 in this inhibition, knockdown of EAT-2 resulted in increased production of IL-12 by CD40-stimulated DC. Assessment of downstream signaling following CD40 cross-linking in the presence or absence of SLAM cross-linking revealed that SLAM coengagement blocked activation of p38 MAPK and JNK signaling pathways in DC, which was reversed in DC with the NZB EAT-2 allele. We conclude that EAT-2 negatively regulates cytokine production in DC downstream of SLAM engagement and that a genetic polymorphism that disturbs this process promotes the development of lupus.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Anticorpos Antinucleares/imunologia , Células Dendríticas/imunologia , Lúpus Eritematoso Sistêmico/genética , Células Th1/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Anticorpos Antinucleares/genética , Sequência de Bases , Ligante de CD40/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Cultivadas , Técnicas de Cocultura , Feminino , Subunidade p35 da Interleucina-12/biossíntese , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos NZB , Dados de Sequência Molecular , Interferência de RNA , RNA Interferente Pequeno , Transdução de Sinais/imunologia , Células Th1/citologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
15.
J Autoimmun ; 58: 100-10, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25678471

RESUMO

Previous studies suggest that the B cells of patients with Systemic Lupus Erythematosus (SLE) are hyper-responsive to BCR crosslinking; however, it has been unclear whether this is the result of altered B cell signaling or differences in various B cell subpopulations in SLE patients as compared to healthy controls. Here we have developed a novel Phosflow technique that permits examination of cell signaling in distinct B cell subpopulations stratified based upon developmental stage and cell surface IgM levels, which we use to show that the naïve B cells of SLE patients are hyper-responsive to IgM receptor crosslinking, resulting in increased SYK phosphorylation. We further demonstrate that this hyper-responsiveness is most marked in the transitional B cell subset and that it is associated with altered function, resulting in decreased apoptosis and increased proliferation of these cells. Examination of repeated samples from the same patients revealed that the hyper-responsiveness fluctuated over time, suggesting that it may be mediated by pro-inflammatory factors rather than genetic variations between patients. In support of this concept, incubation of healthy control B cells with IFN-α or SLE plasma induced the hyper-responsive phenotype, which was blocked by anti-IFN-α antibody. Furthermore, no obvious correlation was seen between genetic variants that are proposed to alter BCR signaling and the increased SYK phosphorylation. The findings suggest that pro-inflammatory factors, in particular Type I IFNs, modulate B cell function in SLE in a way that could contribute to the breach of tolerance in this condition.


Assuntos
Subpopulações de Linfócitos B/imunologia , Linfócitos B/imunologia , Imunoglobulina M/metabolismo , Interferon-alfa/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Adolescente , Adulto , Apoptose/efeitos dos fármacos , Diferenciação Celular , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Feminino , Humanos , Interferon-alfa/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Fosforilação , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Quinase Syk , Adulto Jovem
16.
J Rheumatol ; 41(12): 2421-4, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25320220

RESUMO

OBJECTIVE: The occurrence of monoclonal gammopathy of undetermined significance (MGUS) is common in chronic immune mediated disorders. This increased monoclonal antibody production could result from chronic stimulation of lymphocytes, with the immunoglobulin G (IgG) subtype accounting for the majority of cases in psoriatic arthritis (PsA). We aimed to identify IgG subclass profiles in patients with PsA and to determine association with specific disease characteristics. METHODS: Serum samples from 221 patients with PsA from a single cohort were analyzed for their serum IgG subclass levels. All patients fulfilled the ClASsification for Psoriatic ARthritis (CASPAR) criteria and were followed at 6-month to 12-month intervals according to a standard protocol. MGUS was defined as the occurrence of a discrete band in the gammaglobulin region on at least 2 separate serum protein electrophoresis tests performed 6 months apart. Patients with high abnormal IgG subclass levels were compared to patients with normal levels using descriptive tests. RESULTS: Elevations of IgG1-4 were common in PsA, with ∼20%-49% of patients having elevations of each subclass, IgG2 being the most common subclass abnormality. However, no clinical-serological correlation was found in the group with abnormal IgG2 levels. Of the 38 patients with MGUS, elevations in IgG1 were most common. Patients with an abnormal IgG1 subclass level were more likely to have a discrete band in the gammaglobulin region, higher prevalence of MGUS, and abnormal erythrocyte sedimentation rate or C-reactive protein levels. CONCLUSION: Determination of the IgG subclass concentration in PsA did not seem to add any significant value in identifying specific disease manifestations. However, this study provides insight into the pathological process leading to MGUS in PsA.


Assuntos
Artrite Psoriásica/epidemiologia , Artrite Psoriásica/imunologia , Progressão da Doença , Imunoglobulina G/sangue , Imunoglobulina G/classificação , Gamopatia Monoclonal de Significância Indeterminada/epidemiologia , Gamopatia Monoclonal de Significância Indeterminada/imunologia , Adulto , Idoso , Artrite Psoriásica/sangue , Biomarcadores/sangue , Sedimentação Sanguínea , Proteína C-Reativa/metabolismo , Estudos de Coortes , Comorbidade , Feminino , Humanos , Doenças Inflamatórias Intestinais/sangue , Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/imunologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/sangue , Prevalência , Doenças Reumáticas/sangue , Doenças Reumáticas/epidemiologia , Doenças Reumáticas/imunologia , Uveíte/sangue , Uveíte/epidemiologia , Uveíte/imunologia
17.
Hum Immunol ; 75(8): 873-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24979674

RESUMO

Autoimmune disease is a critical health concern, whose etiology remains enigmatic. We hypothesized that immune responses to somatically mutated self proteins could have a role in the development of autoimmune disease. IFN-γ secretion by T cells stimulated with mitochondrial peptides encoded by published mitochondrial DNA was monitored to test the hypothesis. Human peripheral blood mononuclear cells (PBMCs) of healthy controls and autoimmune patients were assessed for their responses to the self peptides and mutated-self peptides differing from self by one amino acid. None of the self peptides but some of the mutated-self peptides elicited an immune response in healthy controls. In some autoimmune patients, PBMCs responded not only to some of the mutated-self peptides, but also to some of the self peptides, suggesting that there is a breach of self-tolerance in these patients. Although PBMCs from healthy controls failed to respond to self peptides when stimulated with self, the mutated-self peptide could elicit a response to the self peptide upon re-stimulation in vitro, suggesting that priming with mutated-self peptides elicits a cross-reactive response with self. The data raise the possibility that DNA somatic mutations are one of the events that trigger and/or sustain T cell responses in autoimmune diseases.


Assuntos
Autoantígenos/imunologia , Autoimunidade/efeitos dos fármacos , DNA Mitocondrial/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Proteínas Mitocondriais/imunologia , Espondilite Anquilosante/imunologia , Adulto , Idoso , Autoantígenos/genética , Autoantígenos/farmacologia , Estudos de Casos e Controles , Células Cultivadas , Reações Cruzadas , DNA Mitocondrial/genética , Feminino , Humanos , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/patologia , Masculino , Pessoa de Meia-Idade , Mitocôndrias/genética , Mitocôndrias/imunologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/farmacologia , Mutação , Peptídeos/genética , Peptídeos/imunologia , Peptídeos/farmacologia , Tolerância a Antígenos Próprios , Espondilite Anquilosante/genética , Espondilite Anquilosante/patologia , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
18.
PLoS One ; 8(9): e75166, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24073245

RESUMO

We have previously shown that B6 congenic mice with a New Zealand Black chromosome 1 (c1) 96-100 cM interval produce anti-nuclear Abs and that at least two additional genetic loci are required to convert this subclinical disease to fatal glomerulonephritis in mice with a c1 70-100 cM interval (c1(70-100)). Here we show that the number of T follicular helper and IL-21-, IFN-γ-, and IL-17-secreting CD4(+) T cells parallels disease severity and the number of susceptibility loci in these mice. Immunization of pre-autoimmune mice with OVA recapitulated these differences. Differentiation of naïve T cells in-vitro under polarizing conditions and in-vivo following adoptive transfer of OVA-specific TCR transgenic cells into c1(70-100) or B6 recipient mice, revealed T cell functional defects leading to increased differentiation of IFN-γ- and IL-17-producing cells in the 96-100 cM and 88-96 cM intervals, respectively. However, in-vivo enhanced differentiation of pro-inflammatory T cell subsets was predominantly restricted to c1(70-100) recipient mice, which demonstrated altered dendritic cell function, with increased production of IL-6 and IL-12. The data provide support for the role of pro-inflammatory T cells in the conversion of subclinical disease to fatal autoimmunity and highlight the importance of synergistic interactions between individual susceptibility loci in this process.


Assuntos
Autoimunidade/imunologia , Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Mediadores da Inflamação/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Subpopulações de Linfócitos T/imunologia , Animais , Western Blotting , Citocinas/metabolismo , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Feminino , Citometria de Fluxo , Imunofluorescência , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/patologia , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NZB , Camundongos Transgênicos , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia
19.
PLoS One ; 7(5): e36761, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22574220

RESUMO

Genetic loci on New Zealand Black (NZB) chromosomes 1 and 13 play a significant role in the development of lupus-like autoimmune disease. We have previously shown that C57BL/6 (B6) congenic mice with homozygous NZB chromosome 1 (B6.NZBc1) or 13 (B6.NZBc13) intervals develop anti-nuclear antibodies and mild glomerulonephritis (GN), together with increased T and B cell activation. Here, we produced B6.NZBc1c13 bicongenic mice with both intervals, and demonstrate several novel phenotypes including: marked plasmacytoid and myeloid dendritic cell expansion, and elevated IgA production. Despite these changes, only minor increases in anti-nuclear antibody production were seen, and the severity of GN was reduced as compared to B6.NZBc1 mice. Although bicongenic mice had increased levels of baff and tnf-α mRNA in their spleens, the levels of IFN-α-induced gene expression were reduced. Splenocytes from bicongenic mice also demonstrated reduced secretion of IFN-α following TLR stimulation in vitro. This reduction was not due to inhibition by TNF-α and IL-10, or regulation by other cellular populations. Because pDC in bicongenic mice are chronically exposed to nuclear antigen-containing immune complexes in vivo, we examined whether repeated stimulation of mouse pDC with TLR ligands leads to impaired IFN-α production, a phenomenon termed TLR tolerance. Bone marrow pDC from both B6 and bicongenic mice demonstrated markedly inhibited secretion of IFN-α following repeated stimulation with a TLR9 ligand. Our findings suggest that the expansion of pDC and production of anti-nuclear antibodies need not be associated with increased IFN-α production and severe kidney disease, revealing additional complexity in the regulation of autoimmunity in systemic lupus erythematosus.


Assuntos
Anticorpos Antinucleares/imunologia , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Interferon-alfa/biossíntese , Receptores Toll-Like/metabolismo , Animais , Anticorpos Antinucleares/sangue , Células da Medula Óssea/citologia , Contagem de Células , Células Dendríticas/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Interferon-alfa/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Camundongos , Camundongos Congênicos , Baço/citologia
20.
J Immunol ; 186(10): 5845-53, 2011 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-21464090

RESUMO

Numerous mapping studies have implicated genetic intervals from lupus-prone New Zealand Black (NZB) chromosomes 1 and 4 as contributing to lupus pathogenesis. By introgressing NZB chromosomal intervals onto a non-lupus-prone B6 background, we determined that: NZB chromosome 1 congenic mice (denoted B6.NZBc1) developed fatal autoimmune-mediated kidney disease, and NZB chromosome 4 congenic mice (denoted B6.NZBc4) exhibited a marked expansion of B1a and NKT cells in the surprising absence of autoimmunity. In this study, we sought to examine whether epistatic interactions between these two loci would affect lupus autoimmunity by generating bicongenic mice that carry both NZB chromosomal intervals. Compared with B6.NZBc1 mice, bicongenic mice demonstrated significantly decreased mortality, kidney disease, Th1-biased IgG autoantibody isotypes, and differentiation of IFN-γ-producing T cells. Furthermore, a subset of bicongenic mice exhibited a paucity of CD21(+)CD1d(+) B cells and an altered NKT cell activation profile that correlated with greater disease inhibition. Thus, NZBc4 contains suppressive epistatic modifiers that appear to inhibit the development of fatal NZBc1 autoimmunity by promoting a shift away from a proinflammatory cytokine profile, which in some mice may involve NKT cells.


Assuntos
Autoimunidade , Epistasia Genética , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/imunologia , Nefrite Lúpica/genética , Nefrite Lúpica/imunologia , Células T Matadoras Naturais/imunologia , Animais , Antígenos CD1d/genética , Autoanticorpos/biossíntese , Autoanticorpos/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Células Cultivadas , Citometria de Fluxo , Imunofluorescência , Imunoglobulina G/biossíntese , Interferon gama/biossíntese , Lúpus Eritematoso Sistêmico/fisiopatologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos NZB , Polimorfismo Genético , Receptores de Complemento 3d/genética , Linfócitos T/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA