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A balanced immune system is essential to maintain adequate host defense and effective self-tolerance. While an immune system that fails to generate appropriate response will permit infections to develop, uncontrolled activation may lead to autoinflammatory or autoimmune diseases. To identify drug candidates capable of modulating immune cell functions, we screened 1200 small molecules from the Prestwick Chemical Library for their property to inhibit innate or adaptive immune responses. Our studies focused specifically on drug interactions with T cells, B cells, and polymorphonuclear leukocytes (PMNs). Candidate drugs that were validated in vitro were examined in preclinical models to determine their immunomodulatory impact in chronic inflammatory diseases, here investigated in chronic inflammatory skin diseases. Using this approach, we identified several candidate drugs that were highly effective in preclinical models of chronic inflammatory disease. For example, we found that administration of pyrvinium pamoate, an FDA-approved over-the-counter anthelmintic drug, suppressed B cell activation in vitro and halted the progression of B cell-dependent experimental pemphigoid by reducing numbers of autoantigen-specific B cell responses. In addition, in studies performed in gene-deleted mouse strains provided additional insight into the mechanisms underlying these effects, for example, the receptor-dependent actions of tamoxifen that inhibit immune-complex-mediated activation of PMNs. Collectively, our methods and findings provide a vast resource that can be used to identify drugs that may be repurposed and used to promote or inhibit cellular immune responses.
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Food allergies are a growing public health concern worldwide, especially in children and young adults. Allergen-specific IgE plays a central role in the pathogenesis of food allergies, but their titers poorly correlate with allergy development. Host immune systems yield allergen-specific immunoglobulin (Ig)A, IgE and IgG subclasses with low or high affinities and differential Fc N-glycosylation patterns that can affect the allergic reaction to food in multiple ways. High-affinity IgE is required to induce strong mast cell activation eventually leading to allergic anaphylaxis, while low-affinity IgE can even inhibit the development of clinically relevant allergic symptoms. IgA and IgG antibodies can inhibit IgE-mediated mast cell activation through various mechanisms, thereby protecting IgE-positive individuals from allergy development. The production of IgE and IgG with differential allergenic potential seems to be affected by the signaling strength of individual B cell receptors, and by cytokines from T cells. This review provides an overview of the diversity of the B cell response and the diverse roles of antibodies in food allergy.
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B cells play a central role in humoral immunity but also have antibody-independent functions. Studies to date have focused on B cells in blood and secondary lymphoid organs but whether B cells reside in non-lymphoid organs (NLO) in homeostasis is unknown. Here we identify, using intravenous labeling and parabiosis, a bona-fide tissue-resident B cell population in lung, liver, kidney and urinary bladder, a substantial proportion of which are B-1a cells. Tissue-resident B cells are present in neonatal tissues and also in germ-free mice NLOs, albeit in lower numbers than in specific pathogen-free mice and following co-housing with 'pet-store' mice. They spatially co-localise with macrophages and regulate their polarization and function, promoting an anti-inflammatory phenotype, in-part via interleukin-10 production, with effects on bacterial clearance during urinary tract infection. Thus, our data reveal a critical role for tissue-resident B cells in determining the homeostatic 'inflammatory set-point' of myeloid cells, with important consequences for tissue immunity.
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Linfocitos B , Macrófagos , Ratones , Animales , Anticuerpos , Hígado , PulmónRESUMEN
Approximately 5% of the world-wide population is affected by autoimmune diseases. Overall, autoimmune diseases are still difficult to treat, impose a high burden on patients, and have a significant economic impact. Like other complex diseases, e.g., cancer, autoimmune diseases develop over several years. Decisive steps in the development of autoimmune diseases are (i) the development of autoantigen-specific lymphocytes and (often) autoantibodies and (ii) potentially clinical disease manifestation at a later stage. However, not all healthy individuals with autoantibodies develop disease manifestations. Identifying autoantibody-positive healthy individuals and monitoring and inhibiting their switch to inflammatory autoimmune disease conditions are currently in their infancy. The switch from harmless to inflammatory autoantigen-specific T and B-cell and autoantibody responses seems to be the hallmark for the decisive factor in inflammatory autoimmune disease conditions. Accordingly, biomarkers allowing us to predict this progression would have a significant impact. Several factors, such as genetics and the environment, especially diet, smoking, exposure to pollutants, infections, stress, and shift work, might influence the progression from harmless to inflammatory autoimmune conditions. To inspire research directed at defining and ultimately targeting autoimmune predisease, here, we review published evidence underlying the progression from health to autoimmune predisease and ultimately to clinically manifest inflammatory autoimmune disease, addressing the following 3 questions: (i) what is the current status, (ii) what is missing, (iii) and what are the future perspectives for defining and modulating autoimmune predisease.
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Enfermedades Autoinmunes , Autoinmunidad , Humanos , Enfermedades Autoinmunes/etiología , Autoanticuerpos , Autoantígenos , LinfocitosRESUMEN
Mutated and unmutated IgE and IgG play different and partly opposing roles in allergy development, but the mechanisms controlling their relative production are incompletely understood. Here, we analyzed the IgE-response in murine food allergy. Deep sequencing of the complementary-determining region (CDR) repertoires indicated that an ongoing unmutated extrafollicular IgE response coexists with a germinal center response, even after long-lasting allergen challenges. Despite overall IgG1-dominance, a significant proportion of clonotypes contained several-fold more IgE than IgG1. Clonotypes with differential bias to either IgE or IgG1 showed distinct hypermutation and clonal expansion. Hypermutation rates were associated with different physiochemical binding properties of individual B-cell receptors (BCR). Increasing BCR signaling strength inhibited class switching from IgG1 to IgE in vitro, preferentially constraining IgE formation. These data indicate that antigen-binding properties of individual BCRs determine differential IgE hypermutation and IgE versus IgG1 production on the level of single B-cell clones.
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Hipersensibilidad al Huevo , Ratones , Animales , Hipersensibilidad al Huevo/metabolismo , Inmunoglobulina G/metabolismo , Inmunoglobulina E/metabolismo , Receptores de Antígenos de Linfocitos B/genética , Linfocitos B , AlérgenosRESUMEN
As a key anti-inflammatory cytokine, IL-10 is crucial in preventing inflammatory and autoimmune diseases. However, in human and murine lupus, its role remains controversial. Our aim was to understand regulation and immunologic effects of IL-10 on different immune functions in the setting of lupus. This was explored in lupus-prone NZB/W F1 mice in vitro and vivo to understand IL-10 effects on individual immune cells as well as in the complex in vivo setting. We found pleiotropic IL-10 expression that largely increased with progressing lupus, while IL-10 receptor (IL-10R) levels remained relatively stable. In vitro experiments revealed pro- and anti-inflammatory IL-10 effects. Particularly, IL-10 decreased pro-inflammatory cytokines and slowed B cell proliferation, thereby triggering plasma cell differentiation. The frequent co-expression of ICOS, IL-21 and cMAF suggests that IL-10-producing CD4 T cells are important B cell helpers in this context. In vitro and in vivo effects of IL-10 were not fully concordant. In vivo IL-10R blockade slightly accelerated clinical lupus manifestations and immune dysregulation. Altogether, our side-by-side in vitro and in vivo comparison of the influence of IL-10 on different aspects of immunity shows that IL-10 has dual effects. Our results further reveal that the overall outcome may depend on the interplay of different factors such as target cell, inflammatory and stimulatory microenvironment, disease model and state. A comprehensive understanding of such influences is important to exploit IL-10 as a therapeutic target.
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Interleucina-10/inmunología , Lupus Eritematoso Sistémico/inmunología , Inmunidad Adaptativa , Animales , Autoinmunidad , Linfocitos B/inmunología , Linfocitos B/metabolismo , Linfocitos B/patología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Expresión Génica , Humanos , Inmunidad Innata , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Interleucina-10/genética , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/patología , Ratones Endogámicos NZB , Linfocitos T/inmunología , Linfocitos T/metabolismo , Linfocitos T/patologíaRESUMEN
Food allergies are common, costly and potentially life-threatening disorders. They are driven by Th2, but inhibited by Th1 reactions. There is also evidence indicating that IL-2 agonist treatment inhibits allergic sensitization through expansion of regulatory T cells. Here, we tested the impact of an IL-2 agonist in a novel model for food allergy to hen´s egg in mice sensitized without artificial adjuvants. Prophylactic IL-2 agonist treatment expanded Treg populations and inhibited allergen-specific sensitization. However, IL-2 agonist treatment of already sensitized mice increased mast cell responses and allergic anaphylaxis upon allergen re-challenge. These effects depended on allergen-specific IgE and were mediated through IFN-γ, as shown by IgE transfer and blockade of IFN-γ with monoclonal antibodies. These results suggest that although shifting the allergic reaction toward a Treg/Th1 response inhibits allergic sensitization, the prototypic Th1 cytokine IFN-γ promotes mast cell activation and allergen-induced anaphylaxis in individuals that are already IgE-sensitized. Hence, while a Th1 response can prevent the development of food allergy, IFN-γ has the ability to exacerbate already established food allergy.
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Alérgenos/inmunología , Anafilaxia/etiología , Anafilaxia/metabolismo , Alimentos/efectos adversos , Interferón gamma/metabolismo , Interleucina-2/agonistas , Animales , Pollos , Citocinas/metabolismo , Modelos Animales de Enfermedad , Clara de Huevo/efectos adversos , Femenino , Hipersensibilidad a los Alimentos/inmunología , Inmunización , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , RatonesRESUMEN
BACKGROUND: Effector functions of IgG Abs are regulated by their Fc N-glycosylation pattern. IgG Fc glycans that lack galactose and terminal sialic acid residues correlate with the severity of inflammatory (auto)immune disorders and have also been linked to protection against viral infection and discussed in the context of vaccine-induced protection. In contrast, sialylated IgG Abs have shown immunosuppressive effects. OBJECTIVE: We sought to investigate IgG glycosylation programming during the germinal center (GC) reaction following immunization of mice with a foreign protein antigen and different adjuvants. METHODS: Mice were analyzed for GC T-cell, B-cell, and plasma cell responses, as well as for antigen-specific serum IgG subclass titers and Fc glycosylation patterns. RESULTS: Different adjuvants induce distinct IgG+ GC B-cell responses with specific transcriptomes and expression levels of the α2,6-sialyltransferase responsible for IgG sialylation that correspond to distinct serum IgG Fc glycosylation patterns. Low IgG Fc sialylation programming in GC B cells was overall highly dependent on the Foxp3- follicular helper T (TFH) cell-inducing cytokine IL-6, here in particular induced by water-in-oil adjuvants and Mycobacterium tuberculosis. Furthermore, low IgG Fc sialylation programming was dependent on adjuvants that induced IL-27 receptor-dependent IFN-γ+ TFH1 cells, IL-6/IL-23-dependent IL-17A+ TFH17 cells, and high ratios of TFH cells to Foxp3+ follicular regulatory T cells. Here, the 2 latter were dependent on M tuberculosis and its cord factor. CONCLUSION: This study's findings regarding adjuvant-dependent GC responses and IgG glycosylation programming may aid in the development of novel vaccination strategies to induce IgG Abs with both high affinity and defined Fc glycosylation patterns in the GC.
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Adyuvantes Inmunológicos/administración & dosificación , Antígenos/administración & dosificación , Centro Germinal/inmunología , Inmunoglobulina G/inmunología , Compuestos de Alumbre/administración & dosificación , Animales , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Citocinas/inmunología , Femenino , Adyuvante de Freund/administración & dosificación , Glicosilación , Lipopolisacáridos/administración & dosificación , Ratones Endogámicos C57BL , Ratones Noqueados , Aceite Mineral/administración & dosificación , Mycobacterium tuberculosis/inmunología , Ovalbúmina/administración & dosificación , Polisorbatos/administración & dosificación , Escualeno/administración & dosificación , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , VacunaciónRESUMEN
Phenotypic variation of quantitative traits is orchestrated by a complex interplay between the environment (e.g. diet) and genetics. However, the impact of gene-environment interactions on phenotypic traits mostly remains elusive. To address this, we feed 1154 mice of an autoimmunity-prone intercross line (AIL) three different diets. We find that diet substantially contributes to the variability of complex traits and unmasks additional genetic susceptibility quantitative trait loci (QTL). By performing whole-genome sequencing of the AIL founder strains, we resolve these QTLs to few or single candidate genes. To address whether diet can also modulate genetic predisposition towards a given trait, we set NZM2410/J mice on similar dietary regimens as AIL mice. Our data suggest that diet modifies genetic susceptibility to lupus and shifts intestinal bacterial and fungal community composition, which precedes clinical disease manifestation. Collectively, our study underlines the importance of including environmental factors in genetic association studies.
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Cruzamientos Genéticos , Dieta , Genes , Estudios de Asociación Genética , Carácter Cuantitativo Heredable , Animales , Animales no Consanguíneos , Anticuerpos Antinucleares/genética , Bacterias/crecimiento & desarrollo , Biodiversidad , Femenino , Hongos/crecimiento & desarrollo , Predisposición Genética a la Enfermedad , Nefritis Lúpica/genética , Nefritis Lúpica/inmunología , Masculino , Ratones , Microbiota , Mapeo Físico de Cromosoma , Sitios de Carácter Cuantitativo/genética , Bazo/metabolismo , Transcriptoma/genética , Secuenciación Completa del GenomaRESUMEN
B-1 cells constitute a unique subpopulation of lymphocytes residing mainly in body cavities like the peritoneal cavity (PerC) but are also found in spleen and bone marrow (BM). As innate-like B cells, they mediate first line immune defense through low-affinity natural IgM (nIgM) antibodies. PerC B-1 cells can egress to the spleen and differentiate into nIgM antibody-secreting plasma cells that recognize conserved exogenous and endogenous cellular structures. Homing to and homeostasis within the PerC are regulated by the chemokine CXCL13 released by PerC macrophages and stroma cells. However, the exact mechanisms underlying the regulation of CXCL13 and B-1 homeostasis are not fully explored. B-1 cells play important roles in the inflammatory response to infection, autoimmunity, ischemia/reperfusion injury, obesity, and atherosclerosis. Remarkably, this list of inflammatory entities has a strong overlap with diseases that are regulated by complement suggesting a link between B-1 cells and the complement system. Interestingly, up to now, no data exist regarding the role of complement in B-1 cell biology. Here, we demonstrate for the first time that C5a regulates B-1 cell steady-state dynamics within the peritoneum, the spleen, and the BM. We found decreased B-1a cell numbers in the peritoneum and the spleen of C5aR1-/- mice associated with increased B1-a and B1-b numbers in the spleen and high serum titers of nIgM antibodies directed against phosphorylcholine and several pneumococcal polysaccharides. Similarly, peritoneal B-1a cells were decreased in the peritoneum and splenic B-1a and B-1b cells were increased in C5aR2-/- mice. The decrease in peritoneal B-1 cell numbers was associated with decreased peritoneal CXCL13 levels in C5aR1-/- and C5aR2-/- mice. In search for mechanisms, we found that combined TLR2 and IL-10 receptor activation in PerC macrophages induced strong CXCL13 production, which was significantly reduced in cells from C5aR1- and C5aR2-deficient mice and after combined C5aR-targeting. Such stimulation also induced marked local C5 production by PerC macrophages and C5a generation. Importantly, peritoneal in vivo administration of C5a increased CXCL13 production. Taken together, our findings suggest that local non-canonical C5 activation in PerC macrophages fuels CXCL13 production as a novel mechanism to control B-1 cell homeostasis.
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Subgrupos de Linfocitos B/inmunología , Linfocitos B/inmunología , Quimiocina CXCL13/metabolismo , Complemento C5a/metabolismo , Macrófagos/inmunología , Peritoneo/inmunología , Bazo/inmunología , Animales , Células Cultivadas , Citocinas/metabolismo , Homeostasis , Humanos , Inmunidad Innata , Inmunoglobulina M/sangre , Activación de Linfocitos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Receptor de Anafilatoxina C5a/genética , Receptores de Interleucina-10/metabolismo , Células TH1/inmunologíaRESUMEN
Autoantibodies are frequently observed in healthy individuals. In a minority of these individuals, they lead to manifestation of autoimmune diseases, such as rheumatoid arthritis or Graves' disease. Overall, more than 2.5% of the population is affected by autoantibody-driven autoimmune disease. Pathways leading to autoantibody-induced pathology greatly differ among different diseases, and autoantibodies directed against the same antigen, depending on the targeted epitope, can have diverse effects. To foster knowledge in autoantibody-induced pathology and to encourage development of urgently needed novel therapeutic strategies, we here categorized autoantibodies according to their effects. According to our algorithm, autoantibodies can be classified into the following categories: (1) mimic receptor stimulation, (2) blocking of neural transmission, (3) induction of altered signaling, triggering uncontrolled (4) microthrombosis, (5) cell lysis, (6) neutrophil activation, and (7) induction of inflammation. These mechanisms in relation to disease, as well as principles of autoantibody generation and detection, are reviewed herein.
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T cells are key players in autoimmune diseases by supporting the production of autoantibodies. However, their contribution to the effector phase of antibody-mediated autoimmune dermatoses, i.e., tissue injury and inflammation of the skin, has not been investigated. In this paper, we demonstrate that T cells amplify the development of autoantibody-induced tissue injury in a prototypical, organ-specific autoimmune disease, namely epidermolysis bullosa acquisita (EBA) - characterized and caused by autoantibodies targeting type VII collagen. Specifically, we show that immune complex (IC)-induced inflammation depends on the presence of T cells - a process facilitated by T cell receptor (TCR)γδ and NKT cells. Because tissue damage in IC-induced inflammation is neutrophil-dependent, we further analyze the interplay between T cells and neutrophils in an experimental model of EBA. We demonstrate that T cells not only enhance neutrophil recruitment into the site of inflammation but also interact with neutrophils in lymphatic organs. Collectively, this study shows that T cells amplify the effector phase of antibody-induced tissue inflammation.
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Autoanticuerpos/biosíntesis , Epidermólisis Ampollosa Adquirida/inmunología , Células T Asesinas Naturales/inmunología , Neutrófilos/inmunología , Piel/inmunología , Linfocitos T/inmunología , Animales , Anticuerpos Monoclonales/administración & dosificación , Complejo Antígeno-Anticuerpo/química , Complejo Antígeno-Anticuerpo/metabolismo , Comunicación Celular/inmunología , Colágeno Tipo VII/genética , Colágeno Tipo VII/inmunología , Cricetulus , Modelos Animales de Enfermedad , Epidermólisis Ampollosa Adquirida/inducido químicamente , Epidermólisis Ampollosa Adquirida/patología , Expresión Génica , Humanos , Inmunoglobulina G/biosíntesis , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Desnudos , Células T Asesinas Naturales/patología , Neutrófilos/patología , Conejos , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Transducción de Señal , Piel/patología , Bazo/inmunología , Bazo/patología , Linfocitos T/patologíaRESUMEN
Contact hypersensitivity (CHS) of murine skin serves as a model of allergic contact dermatitis. Hapten-specific CD8 T cells and neutrophils represent the major effector cells driving this inflammatory reaction whereas Foxp3(+) regulatory T cells (Tregs) control the severity of inflammation. However, whether in vivo expansion of endogenous Tregs can downregulate CHS-mediated inflammation remains to be elucidated. In this study, we addressed this issue by using injection of an IL-2/anti-IL-2 mAb JES6-1 complex (IL-2/JES6-1) as a means of Treg induction in 2,4,6-trinitrochlorobenzene-induced CHS. IL-2/JES6-1 injection before or after hapten sensitization led to a considerable reduction of skin inflammation, even when rechallenged up to 3 wk after the last treatment. Conversely, Treg depletion re-established the CHS response in IL-2/JES6-1-treated mice. IL-2/JES6-1 injection resulted in increased frequencies of natural and peripheral Tregs in spleen and draining lymph nodes (LNs), elevated IL-10 and TGF-ß production by CD4 T cells, reduced CD86 expression by dendritic cells, and led to lower numbers of hapten-specific IFN-γ-producing CD8 T effector cells in LNs. Neutrophil and CD8 T cell infiltration was reduced in inflamed ear tissue, whereas CTLA-4(+)Foxp3(+) Treg frequencies were augmented. Adoptive transfer of LN cells of sensitized mice into recipients treated with IL-2/JES6-1 showed impaired CHS. Our results show that in vivo Treg expansion results in a prolonged CHS suppression, a sustained reduction of hapten-specific CD8 T cells, and a decrease in effector cell influx in inflamed tissue.
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Linfocitos T CD8-positivos/inmunología , Dermatitis por Contacto/inmunología , Inflamación/inmunología , Activación de Linfocitos , Piel/inmunología , Linfocitos T Reguladores/inmunología , Traslado Adoptivo , Animales , Linfocitos T CD4-Positivos/inmunología , Haptenos/inmunología , Inflamación/tratamiento farmacológico , Interferón gamma/biosíntesis , Interferón gamma/inmunología , Interleucina-10/inmunología , Interleucina-2/administración & dosificación , Ratones , Ratones Endogámicos BALB C , Neutrófilos/inmunología , Piel/patologíaRESUMEN
OBJECTIVE: Explore aorta B-cell immunity in aged apolipoprotein E-deficient (ApoE(-/-)) mice. APPROACH AND RESULTS: Transcript maps, fluorescence-activated cell sorting, immunofluorescence analyses, cell transfers, and Ig-ELISPOT (enzyme-linked immunospot) assays showed multilayered atherosclerosis B-cell responses in artery tertiary lymphoid organs (ATLOs). Aging-associated aorta B-cell-related transcriptomes were identified, and transcript atlases revealed highly territorialized B-cell responses in ATLOs versus atherosclerotic lesions: ATLOs showed upregulation of bona fide B-cell genes, including Cd19, Ms4a1 (Cd20), Cd79a/b, and Ighm although intima plaques preferentially expressed molecules involved in non-B effector responses toward B-cell-derived mediators, that is, Fcgr3 (Cd16), Fcer1g (Cd23), and the C1q family. ATLOs promoted B-cell recruitment. ATLO B-2 B cells included naive, transitional, follicular, germinal center, switched IgG1(+), IgA(+), and IgE(+) memory cells, plasmablasts, and long-lived plasma cells. ATLOs recruited large numbers of B-1 cells whose subtypes were skewed toward interleukin-10(+) B-1b cells versus interleukin-10(-) B-1a cells. ATLO B-1 cells and plasma cells constitutively produced IgM and IgG and a fraction of plasma cells expressed interleukin-10. Moreover, ApoE(-/-) mice showed increased germinal center B cells in renal lymph nodes, IgM-producing plasma cells in the bone marrow, and higher IgM and anti-MDA-LDL (malondialdehyde-modified low-density lipoprotein) IgG serum titers. CONCLUSIONS: ATLOs orchestrate dichotomic, territorialized, and multilayered B-cell responses in the diseased aorta; germinal center reactions indicate generation of autoimmune B cells within the diseased arterial wall during aging.
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Envejecimiento/inmunología , Aorta/inmunología , Enfermedades de la Aorta/inmunología , Apolipoproteínas E/deficiencia , Aterosclerosis/inmunología , Linfocitos B/inmunología , Estructuras Linfoides Terciarias/inmunología , Envejecimiento/genética , Envejecimiento/metabolismo , Animales , Aorta/metabolismo , Aorta/patología , Enfermedades de la Aorta/genética , Enfermedades de la Aorta/metabolismo , Enfermedades de la Aorta/patología , Apolipoproteínas E/genética , Aterosclerosis/genética , Aterosclerosis/metabolismo , Aterosclerosis/patología , Autoanticuerpos/sangre , Autoinmunidad , Linfocitos B/metabolismo , Citocinas/metabolismo , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Predisposición Genética a la Enfermedad , Centro Germinal/inmunología , Centro Germinal/metabolismo , Inmunoglobulinas/sangre , Memoria Inmunológica , Lipoproteínas LDL/inmunología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Masculino , Malondialdehído/análogos & derivados , Malondialdehído/inmunología , Ratones Endogámicos C57BL , Ratones Noqueados , Fenotipo , Células Plasmáticas/inmunología , Células Plasmáticas/metabolismo , Transducción de Señal , Estructuras Linfoides Terciarias/metabolismo , Estructuras Linfoides Terciarias/patología , TranscriptomaRESUMEN
Epidermolysis bullosa acquisita (EBA) is a prototypic organ-specific autoimmune disease induced by autoantibodies to type VII collagen causing mucocutaneous blisters. In the inflammatory (bullous pemphigoid-like) EBA variant, autoantibody binding is followed by a lesional inflammatory cell infiltration, and the overall clinical picture may be indistinguishable from that of bullous pemphigoid, the latter being the most common autoimmune bullous disease. The last decade witnessed the development of several mouse models of inflammatory EBA that facilitated the elucidation of the pathogenesis of autoantibody-induced, cell-mediated subepidermal blistering diseases and identified new therapeutic targets for these and possibly other autoantibody-driven disorders.
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Autoanticuerpos/inmunología , Enfermedades Autoinmunes/patología , Epidermólisis Ampollosa Adquirida/inmunología , Inmunidad Celular/fisiología , Animales , Anticuerpos Monoclonales/uso terapéutico , Enfermedades Autoinmunes/tratamiento farmacológico , Modelos Animales de Enfermedad , Epidermólisis Ampollosa Adquirida/fisiopatología , Femenino , Humanos , Inmunoterapia/métodos , Masculino , Ratones , Pronóstico , Medición de Riesgo , Resultado del TratamientoRESUMEN
INTRODUCTION: Autoantibodies contribute significantly to the pathogenesis of systemic lupus erythematosus (SLE). Unfortunately, the long-lived plasma cells (LLPCs) secreting such autoantibodies are refractory to conventional immunosuppressive treatments. Although generated long before the disease becomes clinically apparent, it remains rather unclear whether LLPC generation continues in the established disease. Here, we analyzed the generation of LLPCs, including autoreactive LLPCs, in SLE-prone New Zealand Black/New Zealand White F1 (NZB/W F1) mice over their lifetime, and their regeneration after depletion. METHODS: Bromodeoxyuridine pulse-chase experiments in mice of different ages were performed in order to analyze the generation of LLPCs during the development of SLE. LLPCs were enumerated by flow cytometry and autoreactive anti-double-stranded DNA (anti-dsDNA) plasma cells by enzyme-linked immunospot (ELISPOT). For analyzing the regeneration of LLPCs after depletion, mice were treated with bortezomib alone or in combination with cyclophosphamide and plasma cells were enumerated 12 hours, 3, 7, 11 and 15 days after the end of the bortezomib cycle. RESULTS: Autoreactive LLPCs are established in the spleen and bone marrow of SLE-prone mice very early in ontogeny, before week 4 and before the onset of symptoms. The generation of LLPCs then continues throughout life. LLPC counts in the spleen plateau by week 10, but continue to increase in the bone marrow and inflamed kidney. When LLPCs are depleted by the proteasome inhibitor bortezomib, their numbers regenerate within two weeks. Persistent depletion of LLPCs was achieved only by combining a cycle of bortezomib with maintenance therapy, for example cyclophosphamide, depleting the precursors of LLPCs or preventing their differentiation into LLPCs. CONCLUSIONS: In SLE-prone NZB/W F1 mice, autoreactive LLPCs are generated throughout life. Their sustained therapeutic elimination requires both the depletion of LLPCs and the inhibition of their regeneration.
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Autoanticuerpos/metabolismo , Lupus Eritematoso Sistémico/metabolismo , Lupus Eritematoso Sistémico/patología , Células Plasmáticas/metabolismo , Células Plasmáticas/patología , Animales , Diferenciación Celular/fisiología , Senescencia Celular/fisiología , Progresión de la Enfermedad , Femenino , Lupus Eritematoso Sistémico/terapia , Ratones , Ratones Endogámicos NZBRESUMEN
Although well-designed prospective trials are generally lacking, intravenous immunoglobulins (IVIG) seem an effective adjuvant treatment for autoimmune bullous skin diseases. Here, efficacy of IVIG monotherapy was compared with corticosteroid treatment in mice with immunization-induced experimental epidermolysis bullosa acquisita (EBA), an autoimmune bullous skin disease characterized by autoantibodies against type VII collagen. We found that IVIG significantly ameliorated clinical disease severity and skin neutrophil infiltration compared with vehicle-treated mice, whereas methylprednisolone showed comparatively less pronounced effects. Efficacy of IVIG was accompanied by reduced levels of autoantibodies, a shift toward noncomplement-fixing autoantibodies, and lower complement deposition at the dermal-epidermal junction. In addition, peripheral Gr-1-positive cells of IVIG-treated animals showed reduced expression of the activating Fcγ receptor IV, which we recently described as a major mediator of tissue injury in experimental EBA. These data show that treatment with IVIG is superior to systemic corticosteroids in experimental EBA and that the effects of IVIG are pleiotropic involving modulation of both the adaptive and innate immune response, although the detailed mode of action of IVIG in this model remains in need of further elucidation.
Asunto(s)
Epidermólisis Ampollosa Adquirida/tratamiento farmacológico , Epidermólisis Ampollosa Adquirida/metabolismo , Inmunoglobulinas Intravenosas/uso terapéutico , Índice de Severidad de la Enfermedad , Corticoesteroides/uso terapéutico , Animales , Autoanticuerpos/metabolismo , Colágeno Tipo VII/inmunología , Modelos Animales de Enfermedad , Ratones , Ratones Mutantes , Receptores de Superficie Celular/metabolismo , Receptores de IgG/metabolismo , Resultado del TratamientoRESUMEN
Antigen-specific Abs are able to enhance or suppress immune responses depending on the receptors that they bind on immune cells. Recent studies have shown that pro- or antiinflammatory effector functions of IgG Abs are also regulated through their Fc N-linked glycosylation patterns. IgG Abs that are agalactosylated (non-galactosylated) and asialylated are proinflammatory and induced by the combination of T cell-dependent (TD) protein antigens and proinflammatory costimulation. Sialylated IgG Abs, which are immunosuppressive, and Tregs are produced in the presence of TD antigens under tolerance conditions. T cell-independent (TI) B cell activation via B cell receptor (BCR) crosslinking through polysaccharides or via BCR and TLR costimulation also induces IgG Abs, but the Fc glycosylation state of these Abs is unknown. We found in mouse experiments that TI immune responses induced suppressive sialylated IgGs, in contrast to TD proinflammatory Th1 and Th17 immune responses, which induced agalactosylated and asialylated IgGs. Transfer of low amounts of antigen-specific sialylated IgG Abs was sufficient to inhibit B cell activation and pathogenic immune reactions. These findings suggest an immune regulatory function for TI immune responses through the generation of immunosuppressive sialylated IgGs and may provide insight on the role of TI immune responses during infection, vaccination, and autoimmunity.
Asunto(s)
Linfocitos B/inmunología , Tolerancia Inmunológica , Inmunoglobulina G/metabolismo , Activación de Linfocitos , Ácidos Siálicos/metabolismo , Linfocitos T/inmunología , Animales , Conformación de Carbohidratos , Secuencia de Carbohidratos , Proliferación Celular , Células Cultivadas , Retroalimentación Fisiológica , Femenino , Glicosilación , Inmunoglobulina M/metabolismo , Lipopolisacáridos/farmacología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Datos de Secuencia Molecular , Procesamiento Proteico-PostraduccionalRESUMEN
Antibodies contribute to the pathogenesis of many chronic inflammatory diseases, including autoimmune disorders and allergies. They are secreted by proliferating plasmablasts, short-lived plasma cells and non-proliferating, long-lived memory plasma cells. Memory plasma cells refractory to immunosuppression are critical for the maintenance of both protective and pathogenic antibody titers. Here, we studied the response of plasma cells in spleen, bone marrow and inflamed kidneys of lupus-prone NZB/W mice to high-dose dexamethasone and/or cyclophosphamide. BrdU+, dividing plasmablasts and short-lived plasma cells in the spleen were depleted while BrdU- memory plasma cells survived. In contrast, all bone marrow plasma cells including anti-DNA secreting cells were refractory to both drugs. Unlike bone marrow and spleen, which showed a predominance of IgM-secreting plasma cells, inflamed kidneys mainly accommodated IgG-secreting plasma cells, including anti-DNA secreting cells, some of which survived the treatments. These results indicate that the bone marrow is the major site of memory plasma cells resistant to treatment with glucocorticoids and anti-proliferative drugs, and that inflamed tissues and secondary lymphoid organs can contribute to the autoreactive plasma cell memory. Therefore, new strategies targeting autoreactive plasma cell memory should be considered. This could be the key to finding a curative approach to the treatment of chronic inflammatory autoantibody-mediated diseases.