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1.
J Autoimmun ; 141: 103114, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37748979

RESUMO

The gastrointestinal tract is home to the largest microbial population in the human body. The gut microbiota plays significant roles in the development of the gut immune system and has a substantial impact on the maintenance of immune tolerance beginning in early life. These microbes interact with the immune system in a dynamic and interdependent manner. They generate immune signals by presenting a vast repertoire of antigenic determinants and microbial metabolites that influence the development, maturation and maintenance of immunological function and homeostasis. At the same time, both the innate and adaptive immune systems are involved in modulating a stable microbial ecosystem between the commensal and pathogenic microorganisms. Hence, the gut microbial population and the host immune system work together to maintain immune homeostasis synergistically. In susceptible hosts, disruption of such a harmonious state can greatly affect human health and lead to various auto-inflammatory and autoimmune disorders. In this review, we discuss our current understanding of the interactions between the gut microbiota and immunity with an emphasis on: a) important players of gut innate and adaptive immunity; b) the contribution of gut microbial metabolites; and c) the effect of disruption of innate and adaptive immunity as well as alteration of gut microbiome on the molecular mechanisms driving autoimmunity in various autoimmune diseases.


Assuntos
Doenças Autoimunes , Microbioma Gastrointestinal , Humanos , Ecossistema , Sistema Imunitário , Imunidade Adaptativa , Tolerância Imunológica , Disbiose
2.
Hepatology ; 75(2): 266-279, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34608663

RESUMO

BACKGROUND AND AIMS: The increased frequency of urinary tract infections in patients with primary biliary cholangitis (PBC) and the cross-reactivity between the lipoyl domains (LD) of human pyruvate dehydrogenase complex (hPDC-E2) and Escherichia coli PDC-E2 (ePDC-E2) have long suggested a role of E. coli in causality of PBC. This issue, however, has remained speculative. We hypothesized that by generating specific constructs of human and E. coli PDC-E2, we would be able to assess the specificity of autoantibody responses and define whether exposure to E. coli in susceptible hosts is the basis for the antimitochondrial antibody (AMA) response. APPROACH AND RESULTS: Importantly, the reactivity of hPDC-E2 LD (hPDC-E2LD) affinity-purified antibodies against hPDC-E2LD could only be removed by prior absorption with hPDC-E2LD and not ePDC-E2, suggesting the presence of unique human PDC-E2 epitopes distinct from E. coli PDC-E2. To identify the autoepitope(s) present in hPDC-E2LD, a more detailed study using a variety of PDC-E2 constructs was tested, including the effect of lipoic acid (LA) on ePDC-E2 conformation and AMA recognition. Individual recombinant ePDCE2 LD domains LD1, LD2 and LD3 did not react with either AMA or antibodies to LA (anti-LA), but in contrast, anti-LA was readily reactive against purified recombinant LD1, LD2, and LD3 expressed in tandem (LP); such reactivity increased when LP was precultured with LA. Moreover, when the three LD (LD1, LD2, LD3) domains were expressed in tandem in pET28a or when LD1 was expressed in another plasmid pGEX, they were lipoylated and reactive to PBC sera. CONCLUSIONS: In conclusion, our data are consistent with an exposure to E. coli that elicits specific antibody to ePDC-E2 resulting in determinant spreading and the classic autoantibody to hPDC-E2LD. We argue this is the first step to development of human PBC.


Assuntos
Autoantígenos/imunologia , Di-Hidrolipoil-Lisina-Resíduo Acetiltransferase/imunologia , Infecções por Escherichia coli/complicações , Escherichia coli/imunologia , Cirrose Hepática Biliar/microbiologia , Mitocôndrias/imunologia , Proteínas Mitocondriais/imunologia , Autoanticorpos/sangue , Estudos de Casos e Controles , Reações Cruzadas/imunologia , Epitopos/imunologia , Escherichia coli/enzimologia , Hepatite Autoimune/sangue , Humanos , Lipoilação , Conformação Molecular/efeitos dos fármacos , Ácido Tióctico/imunologia , Ácido Tióctico/farmacologia
3.
Clin Immunol ; 241: 109079, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35842211

RESUMO

OBJECTIVES: To investigate the differentiation of regulatory T cells (Tregs) induced by methylprednisolone (MP) pulse therapy in patients with Systemic Lupus Erythematosus (SLE). METHODS: We enrolled 30 patients with SLE and analyzed peripheral blood mononuclear cells (PBMCs) before and after MP pulse therapy. Peripheral Tregs, apoptosis of PBMCs subsets, and TGFß production by monocytes was quantified by flow cytometry. Proliferation and IFN-γ production of CD4+ T cells were measured. Furthermore, TGFß1 production by human monocyte-derived macrophages (HMDM) stimulated with MP-treated CD4+ T cells were quantified by ELISA. RESULTS: Peripheral Tregs was significantly increased after MP pulse therapy (6.76 ± 1.46% vs. 3.82 ± 1.02%, p < 0.01), with an expansion of Nrp1- induced Tregs (4.54 ± 0.46% vs. 1.75 ± 0.38%, p < 0.01). Proliferation and IFN-γ production of CD4+ T cells were significantly decreased after MP pulse therapy. MP pulse therapy induced CD4+ T cell apoptosis (early apoptosis, 26.34 ± 3.54% vs. 14.81 ± 2.89%, p < 0.01) and TGFß expression on monocytes (6.02% vs. 2.45%, p < 0.01). Furthermore, MP induced CD4+ T cell apoptosis in vitro, which stimulated HMDM to produce TGFß. Moreover, elevated TGFß level in supernatant from HMDM stimulated with MP-treated CD4+ T cells promoted Tregs differentiation. CONCLUSIONS: MP pulse therapy induces CD4+ T cell apoptosis, which promotes monocytes to produce TGFß and further facilitates Tregs differentiation. Newly-differentiated Tregs suppress proliferation and IFN-γ production of CD4+ T cells and contribute to immunoregulatory milieu after MP pulse therapy.


Assuntos
Lúpus Eritematoso Sistêmico , Linfócitos T Reguladores , Apoptose , Humanos , Leucócitos Mononucleares/metabolismo , Lúpus Eritematoso Sistêmico/metabolismo , Metilprednisolona/farmacologia , Metilprednisolona/uso terapêutico , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta/metabolismo
4.
J Autoimmun ; 132: 102897, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36029718

RESUMO

OBJECTIVE: The ability to regulate B cell development has long been recognized to have therapeutic potential in a variety of autoimmune diseases. However, despite the presence of a classic autoantibody in primary biliary cholangitis (PBC), B cell depleting therapy and indeed therapy with other biologic agents has been disappointing. Unsuccessful treatment using Rituximab is associated with elevation of B-cell activating factor (BAFF) level. Indeed, therapies for PBC remain directed at modulating bile salt biology, rather than targeting effector pathways. With these data in mind, we proposed that targeting two major stages of B cell development, namely long-lived memory B cells and short-lived peripheral autoreactive plasma cells would have therapeutic potential. METHODS: To address this thesis, we administrated anti-BAFF and anti-CD20 monoclonal antibody to ARE-Del mice, a well-characterized murine model of human PBC. We evaluated and compared the therapeutic efficacy of the two agents individually and the combination of anti-BAFF and anti-CD20 in female mice with well-established disease. RESULTS: Our data demonstrate that there was an increased level of B cell depletion that resulted in a significantly more effective clinical and serologic response using the combination of agents as compared with the use of the individual agents. The combination of anti-BAFF and anti-CD20 treatment was more effective in reducing serum levels of antimitochondrial antibody (AMA), total IgM and IgG compared to mice treated with the 2 individual agents. Combination treatment efficiently depleted B cells in the peripheral blood, peritoneal cavity and spleen. Importantly, we identified a unique IgM+ FCRL5+ B cell subset which was sensitive to dual B-cell targeting therapy and depletion of this unique population was associated with reduced portal infiltration and bile duct damage. Taken together, our data indicate that dual B cell targeting therapy with anti-BAFF and anti-CD20 not only led to the efficient depletion of B cells both in the peripheral blood and tissues, but also led to significant clinical improvement. These findings highlight the potential application of combination of anti-BAFF and anti-CD20 in treating patients with PBC. However, additional studies in other animal models of PBC should be undertaken before considering human trials in those PBC patients who have incomplete responses to conventional therapy.


Assuntos
Doenças Autoimunes , Colangite , Humanos , Feminino , Camundongos , Animais , Colangite/tratamento farmacológico , Doenças Autoimunes/tratamento farmacológico , Antígenos CD20 , Autoanticorpos , Imunoglobulina M
5.
Liver Int ; 42(10): 2204-2215, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35791754

RESUMO

BACKGROUND AND AIMS: Our previous studies demonstrated that 2-octynoic acid (2OA) might alter the conformational structure of the inner lipoic acid (LA) binding domain (ILD) in the E2 subunit of pyruvate dehydrogenase complex (PDC-E2), leading to the loss of immune tolerance in simple primary biliary cholangitis (S-PBC). Here, we further explore if this etiological mechanism also accounts for connective tissue disease-associated PBC (CTD-PBC). METHODS: Intein-mediated protein ligation was used to prepare ILD, LA-ILD and 2OA-ILD, and their reactivity with serum samples from 124 S-PBC and 132 CTD-PBC patients was examined. The antibodies to LA, 2OA, LA-ILD and 2OA-ILD, the isotypes of antibodies to LA, 2OA and ILD, were comparatively detected between the two patient groups by enzyme-linked immunosorbent assay and immunoblotting. RESULTS: Both the percentage and reactivity of antibody to 2OA in S-PBC were significantly higher than in CTD-PBC. Antibodies to 2OA and to LA between the two groups separately shared the same characteristics. Remarkably, coexistence of the antibodies to LA-ILD and to 2OA, and coexistence of the antibodies to LA and to 2OA in S-PBC were both significantly more frequent than in CTD-PBC, whereas the percentage of anti-LA antibody without anti-2OA antibody in S-PBC was markedly lower than in CTD-PBC. Moreover, the isotype of antibody to LA was predominantly IgG in CTD-PBC, whilst this isotype was mainly IgM in S-PBC. CONCLUSION: Xenobiotic 2OA might play less important pathogenic role in CTD-PBC than in S-PBC, suggesting that different underlying mechanisms are involved in their immune intolerance to PDC-E2.


Assuntos
Colangite , Doenças do Tecido Conjuntivo , Cirrose Hepática Biliar , Autoanticorpos , Colangite/complicações , Doenças do Tecido Conjuntivo/complicações , Humanos , Imunidade , Xenobióticos/metabolismo
6.
Dig Dis Sci ; 67(7): 2981-2993, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34392493

RESUMO

BACKGROUND: Primary biliary cholangitis (PBC) is an autoimmune disease. CD8 + T cell (CTLs) cytotoxicity played a crucial rule in of PBC with unclear detailed pathogenesis. AIMS: The role of the programmed death-1 (PD-1) pathway in CD8 + T cell cytotoxicity in patients with PBC was determined. METHODS: We recruited 69 patients with PBC and 57 healthy controls (HCs). PD-1 pathway in peripheral CD8 + T cells and related cytokines were detected, and gene expression levels were detected. Immunofluorescence staining of PD-1/PD-L1 was performed on liver tissue. PD-1 ± CTLs were cocultured with human intrahepatic biliary epithelial cells (HiBECs) to measure CTL cytotoxicity, proliferation and cytokine levels and HiBEC apoptosis. The upstream signaling pathway of PD-1 was detected. RESULTS: PBC patients exhibited Tbet gene upregulation and PD-1 downregulation in CTLs, with PD-1 expression reduced in CTLs and PD-L1 reduced in the liver portal region relative to HCs. Higher plasma IL-10, interferon-γ and transforming growth factor-ß concentrations were observed in the PBC group than the HC group. In CTL and HiBEC coculture experiment, compared with PD-1- CTLs, PD-1 + CTLs exhibited weaker cytotoxicity, less proliferation and lower cytokine production. When the system was blocked by anti-PD-1 antibodies, these effects were antagonized. CONCLUSIONS: PD-1 expression in CD8 + T cells decreased, and PD-1 pathway-related cytokines changed in patients with PBC. PD-1/PD-L1 pathway silencing increased CD8 + T cell proliferation, related cytokine production and CTL cytotoxic effects on HiBECs in coculture experiment. The PD-1/PD-L1 pathway might represent an important pathway in the immunological mechanism underlying PBC.


Assuntos
Antígeno B7-H1 , Cirrose Hepática Biliar , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Linfócitos T CD8-Positivos , Citocinas/metabolismo , Regulação para Baixo , Humanos , Cirrose Hepática Biliar/metabolismo , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/metabolismo
7.
Ann Rheum Dis ; 79(4): 518-524, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32114510

RESUMO

BACKGROUND: Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterised by aberrant B cell hyperactivation, whose mechanism is partially understood. METHODS: We performed whole transcriptome sequencing of B cells from three pSS patients and three matched healthy controls (HC). Differentially expression genes (DEGs) were confirmed with B cells from 40 pSS patients and 40 HC by quantitative PCR and western blot. We measured the proliferation potential and immunoglobulins production of siRNA-transfected or plasmid-transfected B cells stimulated with cytosine-phosphate-guanine (CpG) or anti-IgM. We also explored Toll-like receptor 9 (TLR9) signalling to reveal the potential mechanism of B cell hyperactivation in pSS. RESULTS: We identified 77 upregulated and 32 downregulated DEGs in pSS B cells. We confirmed that epithelial stromal interaction (EPST1) expression in pSS B cells was significantly higher than that from HCs. EPSTI1-silencing B cells stimulated with CpG were less proliferated and produced lower level of IgG and IgM comparing with control B cells. EPSTI1-silencing B cells expressed lower level of p-p65 and higher level of IκBα, and B cells with overexpressed EPSTI1 showed higher level of p-p65 and lower level of IκBα. Finally, IκBα degradation inhibitor Dehydrocostus Lactone treatment attenuated p65 phosphorylation promoted by EPSTI1. CONCLUSION: Elevated EPSTI1 expression in pSS B cells promoted TLR9 signalling activation and contributed to the abnormal B cell activation, which was promoted by facilitating p65 phosphorylation and activation of NF-κB signalling via promoting IκBα degradation. EPSTI1 might be implicated in pSS pathogenesis and was a potential therapeutic target of pSS.


Assuntos
Linfócitos B/imunologia , Ativação Linfocitária/imunologia , NF-kappa B/imunologia , Proteínas de Neoplasias/imunologia , Síndrome de Sjogren/imunologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Lactonas , Masculino , Pessoa de Meia-Idade , Inibidor de NF-kappaB alfa/imunologia , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/metabolismo , Proteínas de Neoplasias/metabolismo , Fosforilação , RNA Interferente Pequeno , Sesquiterpenos , Síndrome de Sjogren/metabolismo , Receptor Toll-Like 9/imunologia , Receptor Toll-Like 9/metabolismo , Fator de Transcrição RelA/imunologia , Fator de Transcrição RelA/metabolismo , Adulto Jovem
8.
Clin Rev Allergy Immunol ; 65(2): 101-120, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36757537

RESUMO

The human gastrointestinal tract houses an enormous microbial ecosystem. Recent studies have shown that the gut microbiota plays significant physiological roles and maintains immune homeostasis in the human body. Dysbiosis, an imbalanced gut microbiome, can be associated with various disease states, as observed in infectious diseases, inflammatory diseases, autoimmune diseases, and cancer. Modulation of the gut microbiome has become a therapeutic target in treating these disorders. Fecal microbiota transplantation (FMT) from a healthy donor restores the normal gut microbiota homeostasis in the diseased host. Ample evidence has demonstrated the efficacy of FMT in recurrent Clostridioides difficile infection (rCDI). The application of FMT in other human diseases is gaining attention. This review aims to increase our understanding of the mechanisms of FMT and its efficacies in human diseases. We discuss the application, route of administration, limitations, safety, efficacies, and suggested mechanisms of FMT in rCDI, autoimmune diseases, and cancer. Finally, we address the future perspectives of FMT in human medicine.


Assuntos
Clostridioides difficile , Infecções por Clostridium , Microbiota , Neoplasias , Humanos , Transplante de Microbiota Fecal , Fezes , Clostridioides difficile/fisiologia , Infecções por Clostridium/terapia , Resultado do Tratamento
9.
Cell Mol Immunol ; 19(10): 1130-1140, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36042351

RESUMO

The interferon (IFN) signaling pathways are major immunological checkpoints with clinical significance in the pathogenesis of autoimmunity. We have generated a unique murine model named ARE-Del, with chronic overexpression of IFNγ, by altering IFNγ metabolism. Importantly, these mice develop an immunologic and clinical profile similar to patients with primary biliary cholangitis, including high titers of autoantibodies and portal inflammation. We hypothesized that the downregulation of IFN signaling pathways with a JAK1/2 inhibitor would inhibit the development and progression of cholangitis. To study this hypothesis, ARE-Del+/- mice were treated with the JAK1/2 inhibitor ruxolitinib and serially studied. JAK inhibition resulted in a significant reduction in portal inflammation and bile duct damage, associated with a significant reduction in splenic and hepatic CD4+ T cells and CD8+ T cells. Functionally, ruxolitinib inhibited the secretion of the proinflammatory cytokines IFNγ and TNF from splenic CD4+ T cells. Additionally, ruxolitinib treatment also decreased the frequencies of germinal center B (GC B) cells and T follicular helper (Tfh) cells and led to lower serological AMA levels. Of note, liver and peritoneal macrophages were sharply decreased and polarized from M1 to M2 with a higher level of IRF4 expression after ruxolitinib treatment. Mechanistically, ruxolitinib inhibited the secretion of IL-6, TNF and MCP1 and the expression of STAT1 but promoted the expression of STAT6 in macrophages in vitro, indicating that M1 macrophage polarization to M2 occurred through activation of the STAT6-IRF4 pathway. Our data highlight the significance, both immunologically and clinically, of the JAK/STAT signaling pathway in autoimmune cholangitis.


Assuntos
Doenças Autoimunes , Colangite , Inibidores de Janus Quinases , Animais , Autoanticorpos , Doenças Autoimunes/tratamento farmacológico , Linfócitos T CD8-Positivos , Colangite/tratamento farmacológico , Inflamação , Interferon gama , Interleucina-6 , Inibidores de Janus Quinases/farmacologia , Inibidores de Janus Quinases/uso terapêutico , Camundongos , Nitrilas , Pirazóis , Pirimidinas
10.
Front Immunol ; 12: 684699, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34163483

RESUMO

Connective tissue disease (CTD) related interstitial lung disease (CTD-ILD) is one of the leading causes of morbidity and mortality of CTD. Clinically, CTD-ILD is highly heterogenous and involves rheumatic immunity and multiple manifestations of respiratory complications affecting the airways, vessels, lung parenchyma, pleura, and respiratory muscles. The major pathological features of CTD are chronic inflammation of blood vessels and connective tissues, which can affect any organ leading to multi-system damage. The human lung is particularly vulnerable to such damage because anatomically it is abundant with collagen and blood vessels. The complex etiology of CTD-ILD includes genetic risks, epigenetic changes, and dysregulated immunity, which interact leading to disease under various ill-defined environmental triggers. CTD-ILD exhibits a broad spectra of clinical manifestations: from asymptomatic to severe dyspnea; from single-organ respiratory system involvement to multi-organ involvement. The disease course is also featured by remissions and relapses. It can range from stability or slow progression over several years to rapid deterioration. It can also present clinically as highly progressive from the initial onset of disease. Currently, the diagnosis of CTD-ILD is primarily based on distinct pathology subtype(s), imaging, as well as related CTD and autoantibodies profiles. Meticulous comprehensive clinical and laboratory assessment to improve the diagnostic process and management strategies are much needed. In this review, we focus on examining the pathogenesis of CTD-ILD with respect to genetics, environmental factors, and immunological factors. We also discuss the current state of knowledge and elaborate on the clinical characteristics of CTD-ILD, distinct pathohistological subtypes, imaging features, and related autoantibodies. Furthermore, we comment on the identification of high-risk patients and address how to stratify patients for precision medicine management approaches.


Assuntos
Doenças do Tecido Conjuntivo/complicações , Doenças Pulmonares Intersticiais/etiologia , Autoanticorpos/sangue , Doenças do Tecido Conjuntivo/sangue , Doenças do Tecido Conjuntivo/diagnóstico , Exposição Ambiental , Epigênese Genética , Humanos , Doenças Pulmonares Intersticiais/sangue , Doenças Pulmonares Intersticiais/diagnóstico , Medição de Risco , Fatores de Risco
11.
PeerJ ; 8: e8370, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31988805

RESUMO

Systemic sclerosis is a chronic multisystem autoimmune disease that is associated with polyclonal B cell hyperreactivity. The CDR3 of BCRs is the major site of antigen recognition. Therefore, we analyzed the BCR repertoire of patients with SSc. The BCR repertoires in 12 subjects including eight SSc patients and four healthy controls were characterized by high-throughput sequencing, and bioinformatics analysis were studied. The average CDR3 length in the SSc group was significantly shorter. The SSc patient displayed more diverse BCR. Moreover, SSc patients with mild skin sclerosis, anti-Scl70, interstitial lung disease or female sex were more diversified. B cells from the SSc patients showed a differential V and J gene usage. SSc patients had distinct BCR repertoires.These findings reflected the differences of BCR repertoires between SSc patients and controls. The higher-usage genes for the BCR sequence might be potential biomarkers of B cell-targeted therapies or diagnosis for SSc.

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