RESUMEN
Monocytes play a key role in innate immunity by eliminating pathogens, releasing high levels of cytokines, and differentiating into several cell types, including macrophages and dendritic cells. Similar to other phagocytes, monocytes produce superoxide anions through the NADPH oxidase complex, which is composed of two membrane proteins (p22phox and gp91phox/NOX2) and four cytosolic proteins (p47phox, p67phox, p40phox and Rac1). The pathways involved in NADPH oxidase activation in monocytes are less known than those in neutrophils. Here, we show that p22phox is associated with Rho-associated coiled-coil kinase 2 (ROCK2) in human monocytes but not neutrophils. This interaction occurs between the cytosolic region of p22phox (amino acids 132 to 195) and the coiled-coil region of ROCK2 (amino acids 400 to 967). Interestingly, ROCK2 does not phosphorylate p22phox, p40phox, p67phox, or gp91phox in vitro but phosphorylates p47phox on Ser304, Ser315, Ser320 and Ser328. Furthermore, KD025, a selective inhibitor of ROCK2, inhibited reactive oxygen species (ROS) production and p47phox phosphorylation in monocytes. Specific inhibition of ROCK2 expression in THP1-monocytic cell line by siRNA inhibited ROS production. These data show that ROCK2 interacts with p22phox and phosphorylates p47phox, and suggest that p22phox could be a shuttle for ROCK2 to allow p47phox phosphorylation and NADPH oxidase activation in human monocytes.
Asunto(s)
Monocitos , NADPH Oxidasas , Quinasas Asociadas a rho , Humanos , Aminoácidos , Monocitos/metabolismo , NADPH Oxidasas/metabolismo , Fosfoproteínas/metabolismo , Especies Reactivas de Oxígeno , Quinasas Asociadas a rho/metabolismoRESUMEN
OBJECTIVES: To characterize lymphocytes dysregulation in patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). METHODS: Using flow cytometry, we analysed B- and T-cell subsets in peripheral blood from 37 untreated patients with active disease (29 GPA and 8 MPA) and 22 healthy controls (HCs). RESULTS: GPA patients had increased Th2 (1.8 vs 1.0%, P = 0.02), Th9 (1.1 vs 0.2%, P = 0.0007) and Th17 (1.4 vs 0.9%, P = 0.03) cells compared with HC. Patients with MPO-ANCAs had significantly more CD21- B cells than HC or PR3-ANCA patients (6.9 vs 3.3% and 4.4%, P = 0.01). CD69 expressing B cells were significantly higher in GPA and MPA (3.0 and 5.9 vs 1.4%, P = 0.02 and P = 0.03, respectively) compared with HC, whereas B-cell activating factor-receptor expression was decreased in GPA and MPA (median fluorescence intensity ratio 11.8 and 13.7 vs 45.1 in HC, P < 0.0001 and P = 0.003, respectively). Finally, IL-6-producing B cells were increased in GPA vs HC (25.8 vs 14.9%, P < 0.0001) and decreased in MPA vs HC (4.6 vs 14.9%, P = 0.005), whereas TNF-α-producing B cells were lower in both GPA and MPA patients compared with controls (15 and 8.4 vs 30%, P = 0.01 and P = 0.006, respectively). CONCLUSION: Skewed T-cell polarization towards Th2, Th9 and Th17 responses characterizes GPA, whereas B-cell populations are dysregulated in both GPA and MPA with an activated phenotype and a decreased B-cell activating factor-receptor expression. Finally, inflammatory B cells producing IL-6 are dramatically increased in GPA, providing an additional mechanism by which rituximab could be effective.
Asunto(s)
Linfocitos B/inmunología , Granulomatosis con Poliangitis/sangre , Poliangitis Microscópica/sangre , Linfocitos T/inmunología , Linfocitos B/metabolismo , Citocinas/metabolismo , Citometría de Flujo , Granulomatosis con Poliangitis/inmunología , Granulomatosis con Poliangitis/metabolismo , Humanos , Poliangitis Microscópica/inmunología , Poliangitis Microscópica/metabolismo , Linfocitos T/metabolismoRESUMEN
Human neutrophils have great capacity to cause tissue damage in inflammatory diseases via their inappropriate activation to release reactive oxygen species (ROS), proteases and other tissue-damaging molecules. Furthermore, activated neutrophils can release a wide variety of cytokines and chemokines that can regulate almost every element of the immune system. In addition to these important immuno-regulatory processes, activated neutrophils can also release, expose or generate neoepitopes that have the potential to break immune tolerance and result in the generation of autoantibodies, that characterise a number of human auto-immune diseases. For example, in vasculitis, anti-neutrophil cytoplasmic antibodies (ANCA) that are directed against proteinase 3 or myeloperoxidase are neutrophil-derived autoantigens and activated neutrophils are the main effector cells of vascular damage. In other auto-immune diseases, these neutrophil-derived neoepitopes may arise from a number of processes that include release of granule enzymes and ROS, changes in the properties of components of their plasma membrane as a result of activation or apoptosis, and via the release of Neutrophil Extracellular Traps (NETs). NETs are extracellular structures that contain chromatin that is decorated with granule enzymes (including citrullinated proteins) that can act as neo-epitopes to generate auto-immunity. This review therefore describes the processes that can result in neutrophil-mediated auto-immunity, and the role of neutrophils in the molecular pathologies of auto-immune diseases such as vasculitis, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We discuss the potential role of NETs in these processes and some of the debate in the literature regarding the role of this phenomenon in microbial killing, cell death and auto-immunity.
Asunto(s)
Autoinmunidad , Neutrófilos/inmunología , Neutrófilos/metabolismo , Inmunidad Adaptativa , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/etiología , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/metabolismo , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/patología , Apoptosis/inmunología , Artritis Reumatoide/etiología , Artritis Reumatoide/metabolismo , Artritis Reumatoide/patología , Autoantígenos/inmunología , Trampas Extracelulares/genética , Trampas Extracelulares/inmunología , Humanos , Inmunidad Innata , Lupus Eritematoso Sistémico/etiología , Lupus Eritematoso Sistémico/metabolismo , Lupus Eritematoso Sistémico/patología , Activación Neutrófila/inmunología , Fagocitosis/inmunologíaRESUMEN
Granulomatosis with polyangiitis (GPA) is an autoimmune vasculitis associated with anti-neutrophil-cytoplasmic antibodies (ANCA) against proteinase 3 leading to kidney damage. Neutrophils from those patients have increased expression of membrane proteinase 3 during apoptosis. Here we examined whether neutrophils from patients with GPA have dysregulated protein expressions associated with apoptosis. A global proteomic analysis was performed comparing neutrophils from patients with GPA, with healthy individuals under basal conditions and during apoptosis. At disease onset, the cytosolic proteome of neutrophils of patients with GPA before treatment was significantly different from healthy controls, and this dysregulation was more pronounced following ex vivo apoptosis. Proteins involved in cell death/survival were altered in neutrophils of patients with GPA. Several proteins identified were PR3-binding partners involved in the clearance of apoptotic cells, namely calreticulin, annexin-A1 and phospholipid scramblase 1. These proteins form a platform at the membrane of apoptotic neutrophils in patients with GPA but not healthy individuals and this was associated with the clinical presentation of GPA. Thus, our study shows that neutrophils from patients with GPA have an intrinsic dysregulation in proteins involved in apoptotic cell clearance, which could contribute to the unabated inflammation and autoimmunity in GPA. Hence, harnessing these dysregulated pathways could lead to novel biomarkers and targeted therapeutic opportunities to treat kidney disease.
Asunto(s)
Anexina A1/metabolismo , Apoptosis/inmunología , Autoinmunidad , Granulomatosis con Poliangitis/inmunología , Neutrófilos/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anexina A1/inmunología , Anticuerpos Anticitoplasma de Neutrófilos/inmunología , Biomarcadores/metabolismo , Calreticulina/inmunología , Calreticulina/metabolismo , Femenino , Granulomatosis con Poliangitis/sangre , Granulomatosis con Poliangitis/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Mieloblastina/inmunología , Mieloblastina/metabolismo , Neutrófilos/metabolismo , Proteínas de Transferencia de Fosfolípidos/inmunología , Proteínas de Transferencia de Fosfolípidos/metabolismo , Proteómica , Transducción de Señal/inmunología , Adulto JovenRESUMEN
Proteinase 3 (PR3) is a myeloid serine protease expressed in neutrophils, monocytes, and macrophages. PR3 has a number of well-characterized proinflammatory functions, including cleaving and activating chemokines and controlling cell survival and proliferation. When presented on the surface of apoptotic neutrophils, PR3 can disrupt the normal anti-inflammatory reprogramming of macrophages following the phagocytosis of apoptotic cells. To better understand the function of PR3 in vivo, we generated a human PR3 transgenic mouse (hPR3Tg). During zymosan-induced peritonitis, hPR3Tg displayed an increased accumulation of neutrophils within the peritoneal cavity compared with wild-type control mice, with no difference in the recruitment of macrophages or B or T lymphocytes. Mice were also subjected to cecum ligation and puncture, a model used to induce peritoneal inflammation through infection. hPR3Tg displayed decreased survival rates in acute sepsis, associated with increased neutrophil extravasation. The decreased survival and increased neutrophil accumulation were associated with the cleavage of annexin A1, a powerful anti-inflammatory protein known to facilitate the resolution of inflammation. Additionally, neutrophils from hPR3Tg displayed enhanced survival during apoptosis compared with controls, and this may also contribute to the increased accumulation observed during the later stages of inflammation. Taken together, our data suggest that human PR3 plays a proinflammatory role during acute inflammatory responses by affecting neutrophil accumulation, survival, and the resolution of inflammation.
Asunto(s)
Mieloblastina/metabolismo , Neutrófilos/inmunología , Cavidad Peritoneal/patología , Peritonitis/inmunología , Sepsis/inmunología , Animales , Anexina A1/metabolismo , Apoptosis , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mieloblastina/genética , Peritonitis/inducido químicamente , Fagocitosis , Sepsis/inducido químicamente , ZimosanRESUMEN
Neutrophils are critically involved in host defence and they also modulate the inflammatory process. Turning the inflammatory response towards a resolutive outcome requires a dialogue between apoptotic neutrophils and proresolving macrophages through complex key molecular interactions controlling efferocytosis, anti-inflammatory reprogramming and ultimately immune regulation. In this review, we will first focus on recent molecular analyses aiming at characterizing the role of proteins expressed on apoptotic neutrophils and their cognate partners expressed on macrophages in the resolution of inflammation. These will include chemokine receptors and their ligands and annexin A1 and its receptor FPR2. We will next depict how the structural and enzymatic properties of proteinase 3 (PR3), the autoantigen in vasculitis, allow its expression on apoptotic neutrophils, which in turn affects efferocytosis and immune response associated with the clearance of apoptotic cells. This example illustrates that the fate of apoptotic neutrophils directly influences the resolution of inflammation and immune responses thereby potentially contributing to systemic and nonresolving inflammation as well as autoimmunity.
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Autoinmunidad/fisiología , Activación de Macrófagos/inmunología , Mieloblastina/inmunología , Neutrófilos/fisiología , Animales , Apoptosis/inmunología , Enfermedades Autoinmunes/inmunología , Citocinas/inmunología , Humanos , Inflamación/inmunología , Macrófagos/inmunología , Ratones , Neutrófilos/enzimología , Neutrófilos/inmunología , Fagocitosis/inmunologíaRESUMEN
Neutrophil-associated inflammation during Pseudomonas aeruginosa lung infection is a determinant of morbidity in cystic fibrosis (CF). Neutrophil apoptosis is a key factor in inflammation resolution and is controlled by cytosolic proliferating cell nuclear antigen (PCNA). p21/Waf1, a cyclin-dependent kinase inhibitor, is a partner of PCNA, and its mRNA is up-regulated in human neutrophils during LPS challenge. We show here that, after 7 days of persistent infection with P. aeruginosa, neutrophilic inflammation was more prominent in p21(-/-) compared with wild-type (WT) mice. Notably, no intrinsic defect in the phagocytosis of apoptotic cells by macrophages was found in p21(-/-) compared with WT mice. Inflammatory cell analysis in peritoneal lavages after zymosan-induced peritonitis showed a significantly increased number of neutrophils at 48 hours in p21(-/-) compared with WT mice. In vitro analysis was consistent with delayed neutrophil apoptosis in p21(-/-) compared with WT mice. Ectopic expression of p21/waf1 in neutrophil-differentiated PLB985 cells potentiated apoptosis and reversed the prosurvival effect of PCNA. In human neutrophils, p21 messenger RNA was induced by TNF-α, granulocyte colony-stimulating factor, and LPS. Neutrophils isolated from patients with CF showed enhanced survival, which was reduced after treatment with a carboxy-peptide derived from the sequence of p21/waf1. Notably, p21/waf1 was detected by immunohistochemistry in neutrophils within lungs from patients with CF. Our data reveal a novel role for p21/waf1 in the resolution of inflammation via its ability to control neutrophil apoptosis. This mechanism may be relevant in the neutrophil-dominated inflammation observed in CF and other chronic inflammatory lung conditions.
Asunto(s)
Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Neutrófilos/metabolismo , Neumonía/metabolismo , Neumonía/microbiología , Infecciones por Pseudomonas/metabolismo , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/fisiología , Adolescente , Animales , Apoptosis/efectos de los fármacos , Recuento de Células , Diferenciación Celular/efectos de los fármacos , Línea Celular , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/deficiencia , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Fibrosis Quística/complicaciones , Fibrosis Quística/microbiología , Fibrosis Quística/patología , Femenino , Factor Estimulante de Colonias de Granulocitos/farmacología , Humanos , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/patología , Masculino , Ratones , Modelos Biológicos , Neutrófilos/efectos de los fármacos , Peritonitis/microbiología , Peritonitis/patología , Fagocitosis/efectos de los fármacos , Neumonía/complicaciones , Neumonía/patología , Antígeno Nuclear de Célula en Proliferación/metabolismo , Infecciones por Pseudomonas/complicaciones , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , ZimosanRESUMEN
The contribution of dysregulated innate immune responses to the pathogenesis of allergic disease remains largely unknown. Herein, we addressed the role of Toll-like receptor signaling in airway inflammation by studying mice rendered deficient for the myeloid differentiation factor 88 (MyD88-/-) which results in concurrent deficiencies in TLR and IL-1R1 signaling pathways. We show that the lack of MyD88 offers a partial protection from allergic disease evidenced by reduced airway eosinophilia and production of the Th17-associated effector cytokine IL-17A. By contrast, airway hyperreactivity and Th2 cytokine production, the cardinal features of allergic disease, remained unchanged. We found that the impaired IL-17A production in MyD88-/- mice was associated with defective CD4+ T cells, which failed to respond to IL-23 stimulation. The total number of Th17-associated effectors in lymph nodes was likewise decreased. Taken together, our results demonstrate that MyD88-dependent mechanisms are critical for orchestrating lung inflammatory responses, in terms of IL-17A production, as well as eosinophil and neutrophil recruitment.
Asunto(s)
Eosinófilos/inmunología , Hipersensibilidad/inmunología , Factor 88 de Diferenciación Mieloide/metabolismo , Neutrófilos/inmunología , Neumonía/inmunología , Células Th17/inmunología , Células Th2/inmunología , Animales , Movimiento Celular/genética , Células Cultivadas , Interleucina-17/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factor 88 de Diferenciación Mieloide/genéticaRESUMEN
Plasmacytoid dendritic cells (pDCs) are considered to be the principal type-I IFN (IFN-I) source in response to viruses, whereas the contribution of conventional DCs (cDCs) has been underestimated because, on a per-cell basis, they are not considered professional IFN-I-producing cells. We have investigated their respective roles in the IFN-I response required for CTL activation. Using a nonreplicative virus, baculovirus, we show that despite the high IFN-I-producing abilities of pDCs, in vivo cDCs but not pDCs are the pivotal IFN-I producers upon viral injection, as demonstrated by selective pDC or cDC depletion. The pathway involved in the virus-triggered IFN-I response is dependent on TLR9/MyD88 in pDCs and on stimulator of IFN genes (STING) in cDCs. Importantly, STING is the key molecule for the systemic baculovirus-induced IFN-I response required for CTL priming. The supremacy of cDCs over pDCs in fostering the IFN-I response required for CTL activation was also verified in the lymphocytic choriomeningitis virus model, in which IFN-ß promoter stimulator 1 plays the role of STING. However, when the TLR-independent virus-triggered IFN-I production is impaired, the pDC-induced IFNs-I have a primary impact on CTL activation, as shown by the detrimental effect of pDC depletion and IFN-I signaling blockade on the residual lymphocytic choriomeningitis virus-triggered CTL response detected in IFN-ß promoter stimulator 1(-/-) mice. Our findings reveal that cDCs play a major role in the TLR-independent virus-triggered IFN-I production required for CTL priming, whereas pDC-induced IFNs-I are dispensable but become relevant when the TLR-independent IFN-I response is impaired.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/virología , Citotoxicidad Inmunológica , Células Dendríticas/inmunología , Células Dendríticas/virología , Interferón Tipo I/biosíntesis , Nucleopoliedrovirus/inmunología , Animales , Linfocitos T CD8-positivos/metabolismo , Células Dendríticas/clasificación , Femenino , Virus de la Coriomeningitis Linfocítica/inmunología , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Factor 88 de Diferenciación Mieloide/fisiología , Transducción de Señal/inmunología , Receptor Toll-Like 9/fisiologíaRESUMEN
BACKGROUND: HIV-1 infection results in hyper-immune activation and immunological disorders as early as the asymptomatic stage. Here, we hypothesized that during early HIV-1 infection, HIV-1 Tat protein acts on monocytes/macrophages to induce anti-inflammatory and proinflammatory cytokines and participates in immune dysregulation. RESULTS: In this work we showed that Tat protein: i) by its N-terminal domain induces production of both IL-10 and TNF-α in a TLR4-MD2 dependent manner, ii) interacts specifically with TLR4-MD2 and MD2 with high affinity but not with CD14, iii) induces in vivo TNF-α and IL-10 in a TLR4 dependent manner. CONCLUSIONS: Collectively, our data showed for the first time that, HIV-1 Tat interacts physically with high affinity with TLR4-MD2 to promote proinflammatory cytokines (TNF-α) and the immunosuppressive cytokine IL-10 both involved in immune dysregulation during early HIV-1 infection and AIDS progression.
Asunto(s)
VIH-1/inmunología , Interacciones Huésped-Patógeno , Interleucina-10/biosíntesis , Antígeno 96 de los Linfocitos/metabolismo , Receptor Toll-Like 4/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/metabolismo , Células Cultivadas , Humanos , Interleucina-10/inmunología , Antígeno 96 de los Linfocitos/inmunología , Monocitos/inmunología , Receptor Toll-Like 4/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/inmunologíaRESUMEN
It has been documented that TLR7 stimulation triggers not only antiviral responses, but also alleviates experimental asthma. Considering the implication of invariant NKT (iNKT) cells in both situations, we postulated that they might contribute to the anti-inflammatory effect of TLR7 ligands. We show in this study that spleen cells activated by the TLR7 agonist resiquimod (R848) attenuate allergic inflammation upon adoptive transfer when they are recovered from wild-type, but not from iNKT cell-deficient Jα18(-/-) mice, which proves the specific involvement of this regulatory population. Furthermore, we provide evidence that IFN-γ is critical for the protective effect, which is lost when transferred iNKT cells are sorted from IFN-γ-deficient mice. In support of a direct activation of iNKT cells through TLR7 signaling in vivo, we observed a prompt increase of serum IFN-γ levels, associated with upregulation of CD69 expression on iNKT cells. Moreover, we demonstrate that iNKT cells effectively express TLR7 and respond to R848 in vitro by producing high levels of IFN-γ in the presence of IL-12, consistent with the conclusion that their contribution to the alleviation of allergic inflammation upon treatment with TLR7 ligands is mediated through IFN-γ.
Asunto(s)
Antialérgicos/uso terapéutico , Asma/tratamiento farmacológico , Sistemas de Liberación de Medicamentos/métodos , Imidazoles/uso terapéutico , Mediadores de Inflamación/uso terapéutico , Interferón gamma/biosíntesis , Glicoproteínas de Membrana/agonistas , Células T Asesinas Naturales/inmunología , Receptor Toll-Like 7/agonistas , Traslado Adoptivo , Animales , Asma/inmunología , Asma/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Células T Asesinas Naturales/efectos de los fármacos , Células T Asesinas Naturales/trasplante , Ovalbúmina/administración & dosificación , Ovalbúmina/inmunologíaRESUMEN
The evolution of allergic asthma is tightly controlled by effector and regulatory cells, as well as cytokines such as IL-10 and/or TGF-ß, and it is widely acknowledged that environmental exposure to allergens and infectious agents can influence these processes. In this context, the recognition of pathogen-associated motifs, which trigger TLR activation pathways, plays a critical role with important consequences for disease progression and outcome. We addressed the question whether the TLR7 ligand resiquimod (R848), which has been shown to be protective in several experimental allergic asthma protocols, can also suppress typical asthma symptoms once the disease is established. To this end, we used an OVA-induced experimental model of murine allergic asthma in which R848 was injected after a series of challenges with aerosolized OVA. We found that the treatment attenuated allergic symptoms through a mechanism that required Tregs, as assessed by the expansion of this population in the lungs of mice having received R848, and the loss of R848-mediated suppression of allergic responses after in vivo Treg depletion. IL-10 provided only a minor contribution to this suppressive effect that was largely mediated through a TGF-ß-dependent pathway, a finding that opens new therapeutic opportunities for the pharmacological targeting of Tregs.
Asunto(s)
Asma/tratamiento farmacológico , Asma/inmunología , Imidazoles/farmacología , Glicoproteínas de Membrana/agonistas , Linfocitos T Reguladores/inmunología , Receptor Toll-Like 7/agonistas , Animales , Modelos Animales de Enfermedad , Interleucina-10/inmunología , Pulmón/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ovalbúmina/inmunología , Linfocitos T Reguladores/metabolismo , Factor de Crecimiento Transformador beta/inmunologíaRESUMEN
Neutrophils produce high levels of reactive oxygen species (ROS) by NADPH oxidase that are crucial for host defense but can lead to tissue injury when produced in excess. We previously described that proliferating cell nuclear antigen (PCNA), a nuclear scaffolding protein pivotal in DNA synthesis, controls neutrophil survival through its cytosolic association with procaspases. We herein showed that PCNA associated with p47phox, a key subunit of NADPH oxidase, and that this association regulated ROS production. Surface plasmon resonance and crystallography techniques demonstrated that the interdomain-connecting loop of PCNA interacted directly with the phox homology (PX) domain of the p47phox. PCNA inhibition by competing peptides or by T2AA, a small-molecule PCNA inhibitor, decreased NADPH oxidase activation in vitro. Furthermore, T2AA provided a therapeutic benefit in mice during trinitro-benzene-sulfonic acid (TNBS)-induced colitis by decreasing oxidative stress, accelerating mucosal repair, and promoting the resolution of inflammation. Our data suggest that targeting PCNA in inflammatory neutrophils holds promise as a multifaceted antiinflammatory strategy.
Asunto(s)
Citosol/metabolismo , NADPH Oxidasa 2/metabolismo , NADPH Oxidasas/metabolismo , Neutrófilos/metabolismo , Antígeno Nuclear de Célula en Proliferación/metabolismo , Animales , Línea Celular Tumoral , Células Cultivadas , Colitis/inducido químicamente , Colitis/prevención & control , Activación Enzimática/efectos de los fármacos , Femenino , Humanos , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , NADPH Oxidasas/genética , Unión Proteica , Especies Reactivas de Oxígeno/metabolismo , Bibliotecas de Moléculas Pequeñas/farmacología , Ácido TrinitrobencenosulfónicoRESUMEN
This article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The Publisher apologizes for any inconvenience this may cause.
RESUMEN
It is well documented that compounds from rhizomes of Zingiber officinale, commonly called ginger, have anti-inflammatory properties. Here, we show that ginger can exert such functions in vivo, namely in a mouse model of Th2-mediated pulmonary inflammation. The preparation of ginger aqueous extract (Zo.Aq) was characterized by mass spectrometry as an enriched fraction of n-gingerols. Intraperitoneal injections of this extract before airway challenge of ovalbumin (OVA)-sensitized mice resulted in a marked decrease in the recruitment of eosinophils to the lungs as attested by cell counts in bronchoalveolar lavage (BAL) fluids and histological examination. Resolution of airway inflammation induced by Zo.Aq was accompanied by a suppression of the Th2 cell-driven response to allergen in vivo. Thus, IL-4, IL-5 and eotaxin levels in the lungs as well as specific IgE titres in serum were clearly diminished in ginger-treated mice relative to their controls after allergen sensitization and challenge. Finally, we found that [6]-gingerol, a major constituent of ginger, was sufficient to suppress eosinophilia in our model of inflammation. This is the first evidence that ginger can suppress Th2-mediated immune responses and might thus provide a possible therapeutic application in allergic asthma.
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Asma/tratamiento farmacológico , Eosinofilia/prevención & control , Fitoterapia , Extractos Vegetales/uso terapéutico , Células Th2/inmunología , Zingiber officinale , Animales , Asma/inmunología , Zingiber officinale/química , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ovalbúmina/inmunología , Células TH1/inmunologíaRESUMEN
Granulomatosis with polyangiitis (GPA, Wegener granulomatosis) is a systemic autoimmune vasculitis that affects small arteries, arterioles, and capillaries, most notably in the kidneys and lungs. In this disease, proteinase-3 (PR3), produced by neutrophils, is targeted by antineutrophil cytoplasmic antibodies (ANCA). Recent work by our group has shown how PR3 impairs the resolution of inflammation and deregulates the immune system. Normally, the clearance of activated neutrophils triggers an anti-inflammatory, pro-resolution process. In patients with GPA, however, macrophages phagocytose apoptotic neutrophils then release massive amounts of pro-inflammatory mediators, notably interleukin-1, thereby generating a pro-inflammatory microenvironment conducive to autoimmunity. This deregulation of immune processes is accompanied with activation of plasmacytoid dendritic cells and with polarization of T-helper-2 (Th2), Th9, and Th17 cells. These recent data highlight the dual role of PR3, both auto-antigenic and auto-inflammatory, thus potentially opening up new therapeutic avenues.
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Anticuerpos Anticitoplasma de Neutrófilos/inmunología , Autoinmunidad/inmunología , Granulomatosis con Poliangitis/tratamiento farmacológico , Granulomatosis con Poliangitis/inmunología , Factores Inmunológicos/uso terapéutico , Mieloblastina/inmunología , Apoptosis/inmunología , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Sistemas de Liberación de Medicamentos , Femenino , Granulomatosis con Poliangitis/fisiopatología , Humanos , Masculino , Mieloblastina/metabolismo , Sensibilidad y EspecificidadRESUMEN
Research into neutrophil biology in the last 10 years has uncovered a number of unexpected aspects of this still mysterious innate immune cell. Advances in technology have allowed visualisation of neutrophil trafficking to sites of inflammation, and, remarkably, neutrophils have been observed to depart from the scene in what has been termed reverse migration. There has also been increasing appreciation of the heterogeneity of neutrophils with ongoing categorisation of neutrophil subsets, including myeloid-derived suppressor cells and low-density granulocytes. Newly recognised neutrophil functions include the ability to release novel immune mediators such as extracellular DNA and microvesicles. Finally, studies of neutrophil cell death, both apoptotic and non-apoptotic, have revealed remarkable differences compared to other cell types. This review will highlight important discoveries in these facets of neutrophil biology and how the new findings will inform treatment of diseases where neutrophils are implicated.
Asunto(s)
Trampas Extracelulares/inmunología , Granulocitos/inmunología , Inflamación/inmunología , Células Supresoras de Origen Mieloide/inmunología , Neutrófilos/inmunología , Animales , Apoptosis , Movimiento Celular , Micropartículas Derivadas de Células/metabolismo , HumanosRESUMEN
Proteinase 3 (PR3) is the autoantigen in granulomatosis with polyangiitis, an autoimmune necrotizing vasculitis associated with anti-neutrophil cytoplasmic antibodies (ANCAs). Moreover, PR3 is a serine protease whose membrane expression can potentiate inflammatory diseases such as ANCA-associated vasculitis and rheumatoid arthritis. During apoptosis, PR3 is co-externalized with phosphatidylserine (PS) and is known to modulate the clearance of apoptotic cells through a calreticulin (CRT)-dependent mechanism. The complement protein C1q is one mediator of efferocytosis, the clearance of altered self-cells, particularly apoptotic cells. Since PR3 and C1q are both involved in the clearance of apoptotic cells and immune response modulation and share certain common ligands (i.e., CRT and PS), we examined their possible interaction. We demonstrated that C1q binding was increased on apoptotic rat basophilic leukemia (RBL) cells that expressed PR3, and we demonstrated the direct interaction between purified C1q and PR3 molecules as shown by surface plasmon resonance. To better understand the functional consequence of this partnership, we tested C1q-dependent phagocytosis of the RBL cell line expressing PR3 and showed that PR3 impaired C1q enhancement of apoptotic cell uptake. These findings shed new light on the respective roles of C1q and PR3 in the elimination of apoptotic cells and suggest a novel potential axis to explore in autoimmune diseases characterized by a defect in apoptotic cell clearance and in the resolution of inflammation.
Asunto(s)
Apoptosis , Complemento C1q/inmunología , Mieloblastina/inmunología , Animales , Línea Celular Tumoral , Membrana Celular/inmunología , Humanos , Inflamación , Leucemia Basofílica Aguda/inmunología , Mieloblastina/genética , Neutrófilos/inmunología , Fagocitosis , Unión Proteica , RatasRESUMEN
The onset of type 1 diabetes in NOD mice is delayed by oral administration of a bacterial extract (OM-85) and can be completely prevented by its intraperitoneal administration. Optimal prevention is observed when starting treatment at 3 or 6 weeks of age, and some effect is still observed with treatment at 10 weeks of age. Using genetically deficient mice and cytokine-neutralizing monoclonal antibodies, we demonstrate here that the therapeutic effect does not involve T-helper type 2 cytokines (interleukin [IL]-4 and -10) but is tightly dependent on transforming growth factor (TGF)-beta. Natural killer T-cells also participate in the therapeutic effect because CD1d(-/-) NOD mice are partially resistant to the protective effect of OM-85. The question remains of the specificity of the protective effect of OM-85, which may include proinflammatory components. It will thus be important to further characterize the molecular components that afford protection from type 1 diabetes. Lipopolysaccharide is excluded, but other Toll-like receptor (TLR) agonists could be involved because OM-85 stimulated dendritic cells and induced TGF-beta production by splenocytes in a TLR-2-, TLR-4-, and MyD88-dependent fashion.
Asunto(s)
Extractos Celulares/farmacología , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Células Asesinas Naturales/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Envejecimiento , Animales , Antígenos CD1/genética , Bacterias , Extractos Celulares/uso terapéutico , Diabetes Mellitus Tipo 1/patología , Relación Dosis-Respuesta a Droga , Femenino , Eliminación de Gen , Interleucina-4/genética , Células Asesinas Naturales/efectos de los fármacos , Ligandos , Ratones , Ratones Endogámicos NOD , Factor 88 de Diferenciación Mieloide , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo , Factor de Crecimiento Transformador beta/farmacologíaRESUMEN
Eosinophilic granulomatosis with polyangitis (EGPA) is a rare small- and medium-sized vessel vasculitis belonging to the group of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV). It is commonly divided into two phenotypes depending on the presence of ANCAs targeting myeloperoxidase (MPO). MPO-ANCAs are present in 31% to 38% of patients and are associated with a vasculitis phenotype of the disease, whereas patients without MPO-ANCA are at risk of cardiac involvement. Despite significant advances in understanding the overall pathogenesis of the disease, the explanation for this dichotomy is still unclear. In this review, we synthesize our knowledge of the pathogenesis of EGPA and attempt to i) distinguish EGPA from other diseases including other AAVs, asthma, allergy and hypereosinophilic-associated conditions and ii) speculate about the preponderant mechanisms, which could explain the two disease phenotypes.