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2.
Sci Transl Med ; 11(519)2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31748230

RESUMO

Patients with rheumatoid arthritis (RA) may display atypical CD21-/lo B cells in their blood, but the implication of this observation remains unclear. We report here that the group of patients with RA and elevated frequencies of CD21-/lo B cells shows decreased ataxia telangiectasia-mutated (ATM) expression and activation in B cells compared with other patients with RA and healthy donor controls. In agreement with ATM involvement in the regulation of V(D)J recombination, patients with RA who show defective ATM function displayed a skewed B cell receptor (BCR) Igκ repertoire, which resembled that of patients with ataxia telangiectasia (AT). This repertoire was characterized by increased Jκ1 and decreased upstream Vκ gene segment usage, suggesting improper secondary recombination processes and selection. In addition, altered ATM function in B cells was associated with decreased osteoprotegerin and increased receptor activator of nuclear factor κB ligand (RANKL) production. These changes favor bone loss and correlated with a higher prevalence of erosive disease in patients with RA who show impaired ATM function. Using a humanized mouse model, we also show that ATM inhibition in vivo induces an altered Igκ repertoire and RANKL production by immature B cells in the bone marrow, leading to decreased bone density. We conclude that dysregulated ATM function in B cells promotes bone erosion and the emergence of circulating CD21-/lo B cells, thereby contributing to RA pathophysiology.

3.
Curr Opin Immunol ; 61: 92-99, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31733607

RESUMO

PURPOSE OF REVIEW: FDA-approved B cell-targeted therapy has expanded to a multitude of autoimmune diseases ranging from organ specific diseases, like pemphigus and multiple sclerosis, to systemic diseases such as ANCA-associated vasculitis, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). In this review, we discuss the variability in response to B cell-targeted therapies with a focus on the diversity of human B cells and plasma cells, and will discuss several of the promising new B cell-targeted therapies. RECENT FINDING: The pathogenic roles for B cells include autoantibody-dependent and autoantibody-independent functions whose importance may vary across diseases or even in subsets of patients with the same disease. Recent data have further demonstrated the diversity of human B cell subsets that contribute to disease as well as novel pathways of B cell activation in autoimmune disease. The importance of eliminating autoreactive B cells and plasma cells will be discussed, as well as new approaches to do so. SUMMARY: The past several years has witnessed significant advances in our knowledge of human B cell subsets and function. This has created a nuanced picture of the diverse ways B cells contribute to autoimmunity and an ever-expanding armamentarium of B cell-targeted therapies.

4.
JCI Insight ; 4(20)2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31536480

RESUMO

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by pathologic T cell-B cell interactions and autoantibody production. Defining the T cell populations that drive B cell responses in SLE may enable design of therapies that specifically target pathologic cell subsets. Here, we evaluated the phenotypes of CD4+ T cells in the circulation of 52 SLE patients drawn from multiple cohorts and identified a highly expanded PD-1hiCXCR5-CD4+ T cell population. Cytometric, transcriptomic, and functional assays demonstrated that PD-1hiCXCR5-CD4+ T cells from SLE patients are T peripheral helper (Tph) cells, a CXCR5- T cell population that stimulates B cell responses via IL-21. The frequency of Tph cells, but not T follicular helper (Tfh) cells, correlated with both clinical disease activity and the frequency of CD11c+ B cells in SLE patients. PD-1hiCD4+ T cells were found within lupus nephritis kidneys and correlated with B cell numbers in the kidney. Both IL-21 neutralization and CRISPR-mediated deletion of MAF abrogated the ability of Tph cells to induce memory B cell differentiation into plasmablasts in vitro. These findings identify Tph cells as a highly expanded T cell population in SLE and suggest a key role for Tph cells in stimulating pathologic B cell responses.

6.
Cytokine ; : 154725, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31153744

RESUMO

BACKGROUND: We have previously shown that SLE BMSC have decreased proliferation, increased ROS, increased DNA damage and repair (DDR), a senescence associated secretory phenotype, and increased senescence-associated ß-galactosidase. We have also shown SLE BMSC produce increased amounts of interferon beta (IFNß), have increased mRNA for several genes induced by IFNß, and have a pro-inflammatory feedback loop mediated by a MAVS. To better understand the phenotype of SLE BMSC we conducted mRNA sequencing. METHODS: Patients fulfilling SLE classification criteria and age and sex matched healthy controls were recruited under an Institutional Review Board approved protocol. Bone marrow aspirates and peripheral blood samples were obtained. BMSC were isolated and grown in tissue culture. Early passage BMSC were harvested and mRNA samples were sent for RNAseq. Serum samples were assayed for IFNß by ELISA. RESULTS: On the basis of top differentially expressed genes between SLE and healthy controls, SLE patients with high levels of serum IFNß clustered together while SLE patients with low levels of IFNß clustered with healthy controls. Those genes differentially expressed in SLE patients generally belonged to known IFN pathways, and showed a strong overlap with the set of genes differentially expressed in IFNß high subjects, per se. Moreover, gene expression changes induced by treating healthy BMSC with exogenous IFNß were remarkably similar to gene expression differences in SLE IFNß high vs low BMSC. CONCLUSIONS: BMSCs from SLE patients are heterogeneous. A subgroup of SLE BMSC is distinguished from other SLE BMSC and from controls by increased levels of mRNAs induced by type I interferons. This subgroup of SLE patients had increased levels of IFNß in vivo.

7.
Nat Immunol ; 20(7): 902-914, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31209404

RESUMO

Lupus nephritis is a potentially fatal autoimmune disease for which the current treatment is ineffective and often toxic. To develop mechanistic hypotheses of disease, we analyzed kidney samples from patients with lupus nephritis and from healthy control subjects using single-cell RNA sequencing. Our analysis revealed 21 subsets of leukocytes active in disease, including multiple populations of myeloid cells, T cells, natural killer cells and B cells that demonstrated both pro-inflammatory responses and inflammation-resolving responses. We found evidence of local activation of B cells correlated with an age-associated B-cell signature and evidence of progressive stages of monocyte differentiation within the kidney. A clear interferon response was observed in most cells. Two chemokine receptors, CXCR4 and CX3CR1, were broadly expressed, implying a potentially central role in cell trafficking. Gene expression of immune cells in urine and kidney was highly correlated, which would suggest that urine might serve as a surrogate for kidney biopsies.


Assuntos
Rim/imunologia , Nefrite Lúpica/imunologia , Biomarcadores , Biópsia , Análise por Conglomerados , Biologia Computacional/métodos , Células Epiteliais/metabolismo , Citometria de Fluxo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Imunofenotipagem , Interferons/metabolismo , Rim/metabolismo , Rim/patologia , Leucócitos/imunologia , Leucócitos/metabolismo , Nefrite Lúpica/genética , Nefrite Lúpica/metabolismo , Nefrite Lúpica/patologia , Linfócitos/imunologia , Linfócitos/metabolismo , Anotação de Sequência Molecular , Células Mieloides/imunologia , Células Mieloides/metabolismo , Análise de Célula Única , Transcriptoma
8.
Nat Immunol ; 20(7): 928-942, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31061532

RESUMO

To define the cell populations that drive joint inflammation in rheumatoid arthritis (RA), we applied single-cell RNA sequencing (scRNA-seq), mass cytometry, bulk RNA sequencing (RNA-seq) and flow cytometry to T cells, B cells, monocytes, and fibroblasts from 51 samples of synovial tissue from patients with RA or osteoarthritis (OA). Utilizing an integrated strategy based on canonical correlation analysis of 5,265 scRNA-seq profiles, we identified 18 unique cell populations. Combining mass cytometry and transcriptomics revealed cell states expanded in RA synovia: THY1(CD90)+HLA-DRAhi sublining fibroblasts, IL1B+ pro-inflammatory monocytes, ITGAX+TBX21+ autoimmune-associated B cells and PDCD1+ peripheral helper T (TPH) cells and follicular helper T (TFH) cells. We defined distinct subsets of CD8+ T cells characterized by GZMK+, GZMB+, and GNLY+ phenotypes. We mapped inflammatory mediators to their source cell populations; for example, we attributed IL6 expression to THY1+HLA-DRAhi fibroblasts and IL1B production to pro-inflammatory monocytes. These populations are potentially key mediators of RA pathogenesis.


Assuntos
Artrite Reumatoide/genética , Artrite Reumatoide/metabolismo , Perfilação da Expressão Gênica , Membrana Sinovial/metabolismo , Transcriptoma , Artrite Reumatoide/patologia , Autoimunidade/genética , Biomarcadores , Biologia Computacional/métodos , Estudos Transversais , Citocinas/metabolismo , Fibroblastos/metabolismo , Citometria de Fluxo , Expressão Gênica , Perfilação da Expressão Gênica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Leucócitos/imunologia , Leucócitos/metabolismo , Monócitos/imunologia , Monócitos/metabolismo , Transdução de Sinais , Análise de Célula Única/métodos , Membrana Sinovial/patologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Fluxo de Trabalho
9.
J Autoimmun ; 102: 150-158, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31085070

RESUMO

Systemic lupus (SLE) is characterized by a break of B cell tolerance that plays a central role in disease pathophysiology. An early checkpoint defect occurs at the transitional stage leading to the survival of autoreactive B cells and consequently the production of pathogenic autoantibodies. The main purpose of our work was to determine whether transitional B cells, as the most immature naïve B cell subset upstream of pathogenic B cells, display specific features compared to healthy non SLE subjects. Through extensive analysis of transitional B cells from untreated or low treated, mostly Caucasian, SLE patients, we demonstrated that transitional (T1 and T2) B cell frequencies were increased in SLE and positively correlated with disease activity. SLE transitional B cells displayed defects in two closely inter-related molecules (i.e. TLR9 defective responses and CD19 downregulation). RNA sequencing of sorted transitional B cells from untreated patients revealed a predominant overexpression of interferon stimulated genes (ISGs) even out of flares. In addition, early transitional B cells from the bone marrow displayed the highest interferon score, reflecting a B cell interferon burden of central origin. Hence, the IFN signature in transitional B cells is not confined to African American SLE patients and exists in quiescent disease since the medullary stage. These results suggest that in SLE these 3 factors (i.e. IFN imprintment, CD19 downregulation and TLR9 responses impairment) could take part at the early transitional B cell stage in B cell tolerance by-pass, ultimately leading in periphery to the expansion of autoantibodies-secreting cells.

10.
Front Immunol ; 10: 2881, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31921145

RESUMO

Common variable immunodeficiency (CVID) comprises a group of related disorders defined by defects in B cell function and antibody production. Concurrent autoimmune features are common, but the underlying pathogenic mechanisms of autoimmunity in CVID are poorly understood. Overlap in some clinical and laboratory features suggests a shared pathogenesis, at least in part, with systemic lupus erythematosus (SLE). One important part of SLE pathogenesis is loss of B cell tolerance, an aspect that warrants further study in CVID. The study of inherently autoreactive 9G4+ B cells has led to a greater understanding of B cell tolerance defects in lupus. Study of these B cells in CVID has yielded conflicting results, largely due to differences in methodological approaches. In this study, we take a comprehensive look at 9G4+ B cells throughout B cell development in CVID patients and compare patients both with and without autoimmune features. Using flow cytometry to examine B cell subpopulations in detail, we show that only those CVID patients with autoimmune features demonstrate significant expansion of 9G4+ B cells, both in naïve and multiple memory populations. Examination of two autoreactive B cell subsets recently characterized in SLE, the activated naïve (aNAV) and double negative 2 (DN2) B cells, reveals an expanded 9G4+ DN2 population to be common among CVID patients. These results reveal that both multiple central and peripheral B cell tolerance defects are related to autoimmunity in CVID. Furthermore, these data suggest that the autoreactive DN2 B cell population, which has not previously been examined in CVID, may play an important role in the development of autoimmunity in patients with CVID.

11.
Nat Commun ; 9(1): 5127, 2018 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-30510188

RESUMO

The function of B cells in osteoblast (OB) dysfunction in rheumatoid arthritis (RA) has not been well-studied. Here we show that B cells are enriched in the subchondral and endosteal bone marrow (BM) areas adjacent to osteocalcin+ OBs in two murine RA models: collagen-induced arthritis and the TNF-transgenic mice. Subchondral BM B cells in RA mice express high levels of OB inhibitors, CCL3 and TNF, and inhibit OB differentiation by activating ERK and NF-κB signaling pathways. The inhibitory effect of RA B cells on OB differentiation is blocked by CCL3 and TNF neutralization, and deletion of CCL3 and TNF in RA B cells completely rescues OB function in vivo, while B cell depletion attenuates bone erosion and OB inhibition in RA mice. Lastly, B cells from RA patients express CCL3 and TNF and inhibit OB differentiation, with these effects ameliorated by CCL3 and TNF neutralization. Thus, B cells inhibit bone formation in RA by producing multiple OB inhibitors.


Assuntos
Artrite Reumatoide/imunologia , Linfócitos B/imunologia , Diferenciação Celular/imunologia , Osteoblastos/imunologia , Osteogênese/imunologia , Animais , Artrite Experimental/imunologia , Artrite Experimental/metabolismo , Artrite Reumatoide/metabolismo , Linfócitos B/metabolismo , Medula Óssea/imunologia , Medula Óssea/metabolismo , Humanos , Masculino , Camundongos Endogâmicos DBA , Camundongos Knockout , Camundongos Transgênicos , Osteoblastos/metabolismo , Osteoblastos/patologia , Transdução de Sinais/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo
12.
Immunity ; 49(4): 725-739.e6, 2018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30314758

RESUMO

Systemic Lupus Erythematosus (SLE) is characterized by B cells lacking IgD and CD27 (double negative; DN). We show that DN cell expansions reflected a subset of CXCR5- CD11c+ cells (DN2) representing pre-plasma cells (PC). DN2 cells predominated in African-American patients with active disease and nephritis, anti-Smith and anti-RNA autoantibodies. They expressed a T-bet transcriptional network; increased Toll-like receptor-7 (TLR7); lacked the negative TLR regulator TRAF5; and were hyper-responsive to TLR7. DN2 cells shared with activated naive cells (aNAV), phenotypic and functional features, and similar transcriptomes. Their PC differentiation and autoantibody production was driven by TLR7 in an interleukin-21 (IL-21)-mediated fashion. An in vivo developmental link between aNAV, DN2 cells, and PC was demonstrated by clonal sharing. This study defines a distinct differentiation fate of autoreactive naive B cells into PC precursors with hyper-responsiveness to innate stimuli, as well as establishes prominence of extra-follicular B cell activation in SLE, and identifies therapeutic targets.


Assuntos
Subpopulações de Linfócitos B/imunologia , Linfócitos B/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Receptor 7 Toll-Like/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Subpopulações de Linfócitos B/metabolismo , Linfócitos B/metabolismo , Feminino , Redes Reguladoras de Genes/genética , Redes Reguladoras de Genes/imunologia , Humanos , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/metabolismo , Masculino , Pessoa de Meia-Idade , Plasmócitos/imunologia , Plasmócitos/metabolismo , Receptor 7 Toll-Like/genética , Receptor 7 Toll-Like/metabolismo , Transcriptoma/genética , Transcriptoma/imunologia , Adulto Jovem
13.
Arthritis Res Ther ; 20(1): 139, 2018 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-29996944

RESUMO

BACKGROUND: Detailed molecular analyses of cells from rheumatoid arthritis (RA) synovium hold promise in identifying cellular phenotypes that drive tissue pathology and joint damage. The Accelerating Medicines Partnership RA/SLE Network aims to deconstruct autoimmune pathology by examining cells within target tissues through multiple high-dimensional assays. Robust standardized protocols need to be developed before cellular phenotypes at a single cell level can be effectively compared across patient samples. METHODS: Multiple clinical sites collected cryopreserved synovial tissue fragments from arthroplasty and synovial biopsy in a 10% DMSO solution. Mechanical and enzymatic dissociation parameters were optimized for viable cell extraction and surface protein preservation for cell sorting and mass cytometry, as well as for reproducibility in RNA sequencing (RNA-seq). Cryopreserved synovial samples were collectively analyzed at a central processing site by a custom-designed and validated 35-marker mass cytometry panel. In parallel, each sample was flow sorted into fibroblast, T-cell, B-cell, and macrophage suspensions for bulk population RNA-seq and plate-based single-cell CEL-Seq2 RNA-seq. RESULTS: Upon dissociation, cryopreserved synovial tissue fragments yielded a high frequency of viable cells, comparable to samples undergoing immediate processing. Optimization of synovial tissue dissociation across six clinical collection sites with ~ 30 arthroplasty and ~ 20 biopsy samples yielded a consensus digestion protocol using 100 µg/ml of Liberase™ TL enzyme preparation. This protocol yielded immune and stromal cell lineages with preserved surface markers and minimized variability across replicate RNA-seq transcriptomes. Mass cytometry analysis of cells from cryopreserved synovium distinguished diverse fibroblast phenotypes, distinct populations of memory B cells and antibody-secreting cells, and multiple CD4+ and CD8+ T-cell activation states. Bulk RNA-seq of sorted cell populations demonstrated robust separation of synovial lymphocytes, fibroblasts, and macrophages. Single-cell RNA-seq produced transcriptomes of over 1000 genes/cell, including transcripts encoding characteristic lineage markers identified. CONCLUSIONS: We have established a robust protocol to acquire viable cells from cryopreserved synovial tissue with intact transcriptomes and cell surface phenotypes. A centralized pipeline to generate multiple high-dimensional analyses of synovial tissue samples collected across a collaborative network was developed. Integrated analysis of such datasets from large patient cohorts may help define molecular heterogeneity within RA pathology and identify new therapeutic targets and biomarkers.


Assuntos
Artrite Reumatoide/patologia , Citometria de Fluxo/métodos , Ensaios de Triagem em Larga Escala/métodos , Membrana Sinovial/patologia , Criopreservação , Humanos
14.
JCI Insight ; 3(5)2018 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-29515028

RESUMO

B cells play a central role in systemic lupus erythematosus (SLE) pathophysiology but dysregulated pathways leading to a break in B cell tolerance remain unclear. Since Toll-like receptor 9 (TLR9) favors the elimination of autoreactive B cells in the periphery, we assessed TLR9 function in SLE by analyzing the responses of B cells and plasmacytoid dendritic cells (pDCs) isolated from healthy donors and patients after stimulation with CpG, a TLR9 agonist. We found that SLE B cells from patients without hydroxychloroquine treatment displayed defective in vitro TLR9 responses, as illustrated by the impaired upregulation of B cell activation molecules and the diminished production of various cytokines including antiinflammatory IL-10. In agreement with CD19 controlling TLR9 responses in B cells, decreased expression of the CD19/CD21 complex on SLE B cells was detected as early as the transitional B cell stage. In contrast, TLR7 function was preserved in SLE B cells, whereas pDCs from SLE patients properly responded to TLR9 stimulation, thereby revealing that impaired TLR9 function in SLE was restricted to B cells. We conclude that abnormal CD19 expression and TLR9 tolerogenic function in SLE B cells may contribute to the break of B cell tolerance in these patients.


Assuntos
Antígenos CD19/imunologia , Linfócitos B/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Receptores de Complemento 3d/imunologia , Receptor Toll-Like 9/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD19/metabolismo , Autoimunidade , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Feminino , Humanos , Tolerância Imunológica , Lúpus Eritematoso Sistêmico/sangue , Masculino , Pessoa de Meia-Idade , Oligodesoxirribonucleotídeos/farmacologia , Cultura Primária de Células , Receptores de Complemento 3d/metabolismo , Receptor Toll-Like 9/agonistas , Receptor Toll-Like 9/metabolismo , Regulação para Cima , Adulto Jovem
15.
J Immunol ; 199(2): 458-466, 2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28584005

RESUMO

Neutrophils are well characterized as mediators of peripheral tissue damage in lupus, but it remains unclear whether they influence loss of self-tolerance in the adaptive immune compartment. Lupus neutrophils produce elevated levels of factors known to fuel autoantibody production, including IL-6 and B cell survival factors, but also reactive oxygen intermediates, which can suppress lymphocyte proliferation. To assess whether neutrophils directly influence the progression of autoreactivity in secondary lymphoid organs (SLOs), we characterized the localization and cell-cell contacts of splenic neutrophils at several stages in the progression of disease in the NZB/W murine model of lupus. Neutrophils accumulate in SLO over the course of lupus progression, preferentially localizing near T lymphocytes early in disease and B cells with advanced disease. RNA sequencing reveals that the splenic neutrophil transcriptional program changes significantly over the course of disease, with neutrophil expression of anti-inflammatory mediators peaking during early-stage and midstage disease, and evidence of neutrophil activation with advanced disease. To assess whether neutrophils exert predominantly protective or deleterious effects on loss of B cell self-tolerance in vivo, we depleted neutrophils at different stages of disease. Neutrophil depletion early in lupus resulted in a striking acceleration in the onset of renal disease, SLO germinal center formation, and autoreactive plasma cell production. In contrast, neutrophil depletion with more advanced disease did not alter systemic lupus erythematosus progression. These results demonstrate a surprising temporal and context-dependent role for neutrophils in restraining autoreactive B cell activation in lupus.


Assuntos
Autoimunidade , Progressão da Doença , Centro Germinativo/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Neutrófilos/imunologia , Animais , Autoanticorpos/biossíntese , Autoanticorpos/imunologia , Linfócitos B/imunologia , Modelos Animais de Doenças , Centro Germinativo/citologia , Lúpus Eritematoso Sistêmico/fisiopatologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos NZB , Neutrófilos/fisiologia , Análise de Sequência de RNA , Baço/citologia , Baço/imunologia , Linfócitos T/imunologia
16.
Arthritis Rheumatol ; 68(9): 2244-56, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26990948

RESUMO

OBJECTIVE: Despite considerable advances in the understanding of systemic lupus erythematosus (SLE), there is still an urgent need for new and more targeted treatment approaches. We previously demonstrated that small-molecule blockade of G protein ßγ subunit (Gßγ) signaling inhibits acute inflammation through inhibition of chemokine receptor signal transduction. We undertook this study to determine whether inhibition of Gßγ signaling ameliorates disease in a mouse model of SLE. METHODS: Lupus-prone (NZB × NZW)F1 female mice were prophylactically or therapeutically treated with the small-molecule Gßγ inhibitor gallein. Tissue samples were analyzed by flow cytometry and immunohistochemistry. The development and extent of nephritis were assessed by monitoring proteinuria and by immunohistochemical analysis. Serum immunoglobulin levels were measured by enzyme-linked immunosorbent assay, and total IgG and anti-double-stranded DNA (anti-dsDNA) antibody-secreting cells were measured by enzyme-linked immunospot assay. RESULTS: Gallein inhibited accumulation of T cells and germinal center (GC) B cells in the spleen. Both prophylactic and therapeutic treatment reduced GC size, decreased antibody-secreting cell production in the spleen, and markedly decreased accumulation of autoreactive anti-dsDNA antibody-secreting cells in kidneys. Gallein also reduced immune complex deposition in kidneys. Finally, gallein treatment dramatically inhibited kidney inflammation, prevented glomerular damage, and decreased proteinuria. Mechanistically, gallein inhibited immune cell migration and signaling in response to chemokines in vitro, which suggests that its mechanisms of action in vivo are inhibition of migration of immune cells to sites of inflammation and inhibition of immune cell maturation. CONCLUSION: Overall, these data demonstrate the potential use of gallein or novel inhibitors of Gßγ signaling in SLE treatment.


Assuntos
Subunidades beta da Proteína de Ligação ao GTP/antagonistas & inibidores , Subunidades gama da Proteína de Ligação ao GTP/antagonistas & inibidores , Lúpus Eritematoso Sistêmico/prevenção & controle , Nefrite/prevenção & controle , Xantenos/uso terapêutico , Animais , Feminino , Subunidades beta da Proteína de Ligação ao GTP/fisiologia , Subunidades gama da Proteína de Ligação ao GTP/fisiologia , Lúpus Eritematoso Sistêmico/imunologia , Camundongos , Camundongos Endogâmicos NZB , Nefrite/imunologia , Transdução de Sinais
17.
Arthritis Rheumatol ; 68(4): 805-16, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26554541

RESUMO

OBJECTIVE: Rheumatoid arthritis (RA) is a systemic autoimmune disease that often leads to joint damage. The mechanisms of bone damage in RA are complex, involving activation of bone-resorbing osteoclasts (OCs) by synoviocytes and Th17 cells. This study was undertaken to investigate whether B cells play a direct role in osteoclastogenesis through the production of RANKL, the essential cytokine for OC development. METHODS: RANKL production by total B cells or sorted B cell subpopulations in the peripheral blood and synovial tissue from healthy donors or anti-cyclic citrullinated peptide-positive patients with RA was examined by flow cytometry, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemical analysis. To define direct effects on osteoclastogenesis, B cells were cocultured with CD14+ monocytes, and OCs were enumerated by tartrate-resistant acid phosphatase staining. RESULTS: Healthy donor peripheral blood B cells were capable of expressing RANKL upon stimulation, with switched memory B cells (CD27+IgD-) having the highest propensity for RANKL production. Notably, switched memory B cells in the peripheral blood from RA patients expressed significantly more RANKL compared to healthy controls. In RA synovial fluid and tissue, memory B cells were enriched and spontaneously expressed RANKL, with some of these cells visualized adjacent to RANK+ OC precursors. Critically, B cells supported OC differentiation in vitro in a RANKL-dependent manner, and the number of OCs was higher in cultures with RA B cells than in those derived from healthy controls. CONCLUSION: These findings reveal the critical importance of B cells in bone homeostasis and their likely contribution to joint destruction in RA.


Assuntos
Artrite Reumatoide/metabolismo , Linfócitos B/metabolismo , Reabsorção Óssea/metabolismo , Diferenciação Celular/imunologia , Osteoclastos/metabolismo , Ligante RANK/metabolismo , RNA Mensageiro/metabolismo , Fosfatase Ácida/metabolismo , Artrite Reumatoide/imunologia , Linfócitos B/imunologia , Reabsorção Óssea/imunologia , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Isoenzimas/metabolismo , Monócitos , Osteoclastos/imunologia , Ligante RANK/imunologia , Reação em Cadeia da Polimerase em Tempo Real , Líquido Sinovial , Membrana Sinovial/citologia , Membrana Sinovial/imunologia , Membrana Sinovial/metabolismo , Fosfatase Ácida Resistente a Tartarato
18.
Curr Opin Rheumatol ; 27(5): 461-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26164595

RESUMO

PURPOSE OF REVIEW: Our understanding of the physiological and pathogenic functions of B cells in systemic lupus erythematosus (SLE) and Primary Sjögren's syndrome (pSS) continues to expand. In this review, we discuss novel insights published in the last 18 months into the roles of B cells in systemic autoimmunity. RECENT FINDINGS: Data have continued to expand regarding the diverse mechanisms by which innate immune signals including Toll-like receptors (TLRs) regulate the B cell compartment. Localized B cells and long-lived plasma cells have been identified as playing an important role in target tissue including the development of ectopic lymphoid structures in kidney and salivary gland. In addition to pathogenic roles for B cells, there is mounting evidence for regulatory B cell subsets that play a protective role and new insights into the signals that regulate their development. SUMMARY: The past few years have provided insights into the multiple paths by which innate immune signals can lead to B cell activation in SLE and pSS and the increasingly diverse ways in which B cells contribute to disease expression. Further understanding the imbalance between protective and pathogenic functions for B cells in disease including in understudied target tissue should yield new treatment approaches.


Assuntos
Linfócitos B/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Síndrome de Sjogren/imunologia , Imunidade Adaptativa , Autoimunidade , Humanos , Imunidade Inata , Imunoterapia
19.
PLoS One ; 10(6): e0128269, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26047509

RESUMO

Although B cell depletion therapy (BCDT) is effective in a subset of rheumatoid arthritis (RA) patients, both mechanisms and biomarkers of response are poorly defined. Here we characterized abnormalities in B cell populations in RA and the impact of BCDT in order to elucidate B cell roles in the disease and response biomarkers. In active RA patients both CD27+IgD- switched memory (SM) and CD27-IgD- double negative memory (DN) peripheral blood B cells contained significantly higher fractions of CD95+ and CD21- activated cells compared to healthy controls. After BCD the predominant B cell populations were memory, and residual memory B cells displayed a high fraction of CD21- and CD95+ compared to pre-depletion indicating some resistance of these activated populations to anti-CD20. The residual memory populations also expressed more Ki-67 compared to pre-treatment, suggesting homeostatic proliferation in the B cell depleted state. Biomarkers of clinical response included lower CD95+ activated memory B cells at depletion time points and a higher ratio of transitional B cells to memory at reconstitution. B cell function in terms of cytokine secretion was dependent on B cell subset and changed with BCD. Thus, SM B cells produced pro-inflammatory (TNF) over regulatory (IL10) cytokines as compared to naïve/transitional. Notably, B cell TNF production decreased after BCDT and reconstitution compared to untreated RA. Our results support the hypothesis that the clinical and immunological outcome of BCDT depends on the relative balance of protective and pathogenic B cell subsets established after B cell depletion and repopulation.


Assuntos
Artrite Reumatoide/imunologia , Artrite Reumatoide/terapia , Linfócitos B/imunologia , Linfócitos B/patologia , Depleção Linfocítica/métodos , Idoso , Antirreumáticos/uso terapêutico , Artrite Reumatoide/patologia , Linfócitos B/efeitos dos fármacos , Biomarcadores/análise , Feminino , Humanos , Imunoglobulina D/análise , Imunoglobulina D/imunologia , Interleucina-10/análise , Interleucina-10/imunologia , Antígeno Ki-67/análise , Antígeno Ki-67/imunologia , Masculino , Pessoa de Meia-Idade , Receptores de Complemento 3d/análise , Receptores de Complemento 3d/imunologia , Rituximab/uso terapêutico , Fator de Necrose Tumoral alfa/análise , Fator de Necrose Tumoral alfa/imunologia , Receptor fas/análise , Receptor fas/imunologia
20.
J Clin Invest ; 124(7): 3200-14, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24892805

RESUMO

NOTCH-dependent signaling pathways are critical for normal bone remodeling; however, it is unclear if dysfunctional NOTCH activation contributes to inflammation-mediated bone loss, as observed in rheumatoid arthritis (RA) patients. We performed RNA sequencing and pathway analyses in mesenchymal stem cells (MSCs) isolated from transgenic TNF-expressing mice, a model of RA, to identify pathways responsible for decreased osteoblast differentiation. 53 pathways were dysregulated in MSCs from RA mice, among which expression of genes encoding NOTCH pathway members and members of the noncanonical NF-κB pathway were markedly elevated. Administration of NOTCH inhibitors to RA mice prevented bone loss and osteoblast inhibition, and CFU-fibroblasts from RA mice treated with NOTCH inhibitors formed more new bone in recipient mice with tibial defects. Overexpression of the noncanonical NF-κB subunit p52 and RELB in a murine pluripotent stem cell line increased NOTCH intracellular domain-dependent (NICD-dependent) activation of an RBPjκ reporter and levels of the transcription factor HES1. TNF promoted p52/RELB binding to NICD, which enhanced binding at the RBPjκ site within the Hes1 promoter. Furthermore, MSC-enriched cells from RA patients exhibited elevated levels of HES1, p52, and RELB. Together, these data indicate that persistent NOTCH activation in MSCs contributes to decreased osteoblast differentiation associated with RA and suggest that NOTCH inhibitors could prevent inflammation-mediated bone loss.


Assuntos
Artrite Reumatoide/metabolismo , NF-kappa B/metabolismo , Osteoblastos/metabolismo , Receptores Notch/metabolismo , Animais , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/patologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Reabsorção Óssea/metabolismo , Reabsorção Óssea/patologia , Reabsorção Óssea/prevenção & controle , Diferenciação Celular , Dipeptídeos/farmacologia , Modelos Animais de Doenças , Expressão Gênica , Proteínas de Homeodomínio/genética , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , NF-kappa B/genética , Subunidade p52 de NF-kappa B/genética , Subunidade p52 de NF-kappa B/metabolismo , Osteoblastos/efeitos dos fármacos , Osteoblastos/patologia , Regiões Promotoras Genéticas , Receptores Notch/antagonistas & inibidores , Receptores Notch/genética , Transdução de Sinais , Fatores de Transcrição HES-1 , Fator de Transcrição RelB/genética , Fator de Transcrição RelB/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
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