Cryptococcus neoformans in Association with Dermatophagoides pteronyssinus has Pro- (IL-6/STAT3 Overproduction) and Anti-inflammatory (CCL2/ERK1/2 Downregulation) Effects on Human Bronchial Epithelial Cells.

Cryptococcosis (caused, for example, by Cryptococcus neoformans) and allergic asthma (caused, for example, by Dermatophagoides pteronyssinus) target the respiratory tract (the lung and bronchial epithelium). C. neoformans and D. pteronyssinus can coexist in the same indoor environment, and exposure to both can cause alterations in the local airway inflammatory milieu and exacerbation of airway inflammatory diseases. Here, we evaluated the effects of the association between C. neoformans and D. pteronyssinus in the modulation of airway inflammatory responses in an in vitro experimental model using human bronchial epithelial cells. BEAS-2B cells were cultivated and stimulated with D. pteronyssinus (10 µg/mL) and/or C. neoformans (MOI 100) for 24 h. No cytotoxic effect was observed in cells stimulated by C. neoformans and/or D. pteronyssinus. The production of IL-8, IL-6, and/or CCL2, but not IL-10, as well as the activation of NF-kB, STAT3, STAT6, and/or ERK1/2 were increased in cells stimulated by C. neoformans or D. pteronyssinus compared to controls. C. neoformans in association with D. pteronyssinus inhibited the CCL2­ERK1/2 signaling pathway in cells treated with both pathogens compared to cells stimulated by D. pteronyssinus alone. In addition, their association induced an additive effect on the IL-6/STAT3 signaling pathway in cells compared to cells stimulated with D. pteronyssinus or C. neoformans only. D. pteronyssinus increased the internalization and growth of C. neoformans in BEAS-2B cells. D. pteronyssinus in association with C. neoformans promoted pro- and anti-inflammatory responses, which can modulate cryptococcal infection and asthmaticus status.

Effects of cigarette smoke extract on bronchial epithelial cells stimulated with Cryptococcus neoformans.

In the airways, the adhesion of Cryptococcus neoformans with airway epithelial cells is crucial for the establishment of cryptococcosis. Tobacco smoke is considered a risk factor for cryptococcosis. Here, we evaluated the effects of cigarette smoke extract (CSE) on human bronchial epithelial cells (BEAS-2B) stimulated with C. neoformans. Multiplicities of infection (MOIs) of 1-100 of C. neoformans per cell led to increased IL-8 production and no cytotoxic effects when compared to those of controls. C. neoformans (MOI 100) also significantly increased the concentration of IL-6. In cells stimulated with CSE doses (1.0, 2.5 and 5.0%) from one or five cigarettes, increased IL-1ß production was observed only in doses from one (1.0%) and five (2.5%) cigarettes when compared to that of controls. However, only 1.0% CSE failed to show cytotoxic effects. In addition, CSE significantly increased the concentration of IL-8. Cells stimulated with both CSE and C. neoformans demonstrated a reduction in IL-6/STAT3 signalling compared to that in cells stimulated by C. neoformans. In addition, a significant increase in IL-10 production was also observed. No alterations in NF-kB or ICAM-1 expression were observed among the groups. The combination of CSE and C. neoformans favoured the increase of fungal numbers and extracellular adhering of C. neoformans on BEAS-2B cells. In addition, the internalization of C. neoformans on BEAS-2B cells was reduced after CSE stimulation. In conclusion, the association of CSE and C. neoformans induced an anti-inflammatory effect in bronchial epithelial cells, which might favour the development of C. neoformans infection in the airways.

IL-27 regulates IL-4-induced chemokine production in human bronchial epithelial cells.

IL-4 coordinates the Th2-type immune response in inflammatory diseases such as asthma. IL-27 can inhibit the development of both Th2 and Th1 cells. However, IL-27 can also drive naïve T cells to differentiate toward the Th1 phenotype. In this study, we investigated the effects of IL-27 on the activation of IL-4-induced human bronchial epithelial cells (BEAS-2B). Compared to controls, both IL-4 and IL-27 (25-100 ng/mL) increased the concentrations of CCL2 and IL-8 in a dose-dependent manner. However, compared to cells stimulated individually with IL-4 or IL-27, treatment with a combination of both cytokines reduced CCL2 and IL-8 concentrations in a dose- and time-dependent manner. IL-4 increased the activation of p38 MAPK, ERK1/2, STAT6 and NF-κB, while IL-27 increased the activation of p38 MAPK and ERK1/2 but not STAT6 and NF-κB. Compared to IL-4-stimulated cells, cells treated with both IL-27 and IL-4 displayed decreased activation of STAT6 and NF-κB but not ERK1/2 and p38 MAPK. Taken together, these results suggest that IL-27 plays a pro-inflammatory role when administered alone but downregulates bronchial epithelial cell activation when combined with IL-4. Therefore, IL-27 may be an interesting target for the treatment of Th2 inflammatory diseases.

Interferon-gamma signaling is downregulated in peripheral blood mononuclear cells from asthma patients / A sinalização de interferon-gama é diminuída em células mononucleares do sangue periférico de pacientes asmáticos

Introduction: Interferon-gamma (IFN-g) signaling is mediated by crosstalk of receptors, such as IFN-g receptor 1 (IFN-g R1), transcription factors, such as signal transducer and activator of transcription 1 (STAT1) and suppressors of cytokine signaling 1 (SOCS1). Here, we evaluated the role of IFN-g signaling in peripheral blood mononuclear cells (PBMCs) from asthma patients and control individuals. Methods: PBMCs from adult healthy nonasthmatic controls (n = 12; male and female, 18-60 years old) and patients diagnosed with asthma (n = 18; male and female, 18-60 years old) were stimulated with IFN-g (0.25, 0.5 and/or 1.0 ng/mL) and, after 24h, the production of CXC motif chemokine 10 (CXCL10) was evaluated (by enzyme linked immunosorbent assay) as well as the expression of IFN-g R1, STAT1 (both by flow cytometry assay) and SOCS1 (by real-time qPCR assay). Results: CXCL10 production was reduced in a dose-dependent manner in PBMCs from asthma patients stimulated with IFN-g when compared to control individuals. While IFN-g induced an increase in IFN-g R1 expression and phosphorylated STAT1 (pSTAT1) activation in PBMCs from the control group, a reduction in both IFN-g R1 and pSTAT1 was observed in PBMCs from asthma patients. IFN-g increased SOCS1 mRNA expression in PBMCs from asthma patients when compared to IFN-g-stimulated cells from control individuals. Conclusion: Taken together, our results demonstrated that IFN-g signaling is downregulated in asthma patients.

Introdução: A sinalização de interferon-gama (IFN-g) é mediada por receptores, como o receptor 1 de IFN-gama (IFN-gR1), fatores de transcrição, como o transdutor de sinal e o ativador de transcrição 1 (STAT1) e supressores de sinalização de citocina 1 (SOCS1). Neste trabalho, avaliamos o papel da sinalização de IFN-g em células mononucleares do sangue periférico (PBMCs) de indivíduos com asma e controle. Métodos: Células mononucleares do sangue periférico (PBMCs) de adultos saudáveis e não asmáticos (n = 12, homens e mulheres, 18-60 anos) e pacientes diagnosticados com asma (n = 18, homens e mulheres, 18-60 anos) foram estimuladas com IFN-g (0,25, 0,5 e/ou 1,0 ng/mL) e após 24 horas a produção de CXCL10 foi avaliada por ensaio de imunoabsorção enzimática (ELISA), bem como o receptor 1 de IFN-g (IFN-g R1). Também foram avaliadas as expressões do transdutor de sinal e ativador da transcrição 1 (STAT1) (por citometria de fluxo) e supressor de expressão de sinalização de citocinas 1 (SOCS1) (por ensaio qPCR em tempo real). Resultados: A produção de CXCL10, uma quimiocina induzida por IFNg, foi reduzida de maneira dependente da dose em PBMCs de pacientes com asma estimulados com IFN-g (0,25-1,0 ng/mL) quando comparado ao grupo controle. Enquanto IFN-g induziu um aumento da expressão de IFN-g R1 e ativação da fosforilação de STAT1 (pSTAT1) em PBMCs do grupo controle, uma redução de ambas (IFN-g R1 e pSTAT1) foi observada em PBMCs de pacientes com asma. O IFN-g aumentou as PBMCs de expressão do mRNA de SOCS1 de pacientes com asma quando comparado às células estimuladas por IFN-g do controle. Conclusão: Em conjunto, nossos resultados demonstraram que a sinalização de IFN-g é sub-regulada em pacientes com asma.

AT-RvD1 modulates the activation of bronchial epithelial cells induced by lipopolysaccharide and Dermatophagoides pteronyssinus.

Bronchial epithelial cells are essential to airways homeostasis; however, they are also involved in exacerbation of airway inflammatory responses of patients with conditions such as asthma. Dermatophagoides pteronyssinus (Dp), the most important allergen, and lipopolysaccharide (LPS), both of which are present in house dust mites (HDM), can activate immune and structural cells (such as bronchial epithelial cells) and modulate the airway inflammation in asthma patients. Resolvin D1 (RvD1) and its epimer aspirin-triggered-resolvin D1 (AT-RvD1) are lipid mediators that are produced during the resolution of inflammation and demonstrate anti-inflammatory and pro-resolution effects in several experimental models including experimental models of allergic airway inflammation. Here, we evaluated the effects of AT-RvD1 (10-12-10-10 M) on human bronchial epithelial cells (BEAS-2B) stimulated with LPS (2µg/ml) or Dp (10µg/ml). After 24h, the C-C motif chemokine ligand 2 (CCL-2) production was increased in cells that had been stimulated with LPS and Dp compared to the control. However, AT-RvD1 (10-11 and 10-10 M) significantly reduced the concentration of CCL-2 in a manner that was dependent on the N-formyl peptide receptor 2 (FPR2/ALX) and nuclear factor kappa B (NF-κB) pathways in cells stimulated with LPS or Dp compared to controls. In addition, AT-RvD1 reduced the phosphorylation of signal transducer and activator of transcription (STAT)6 and STAT1 in cells stimulated with Dp and LPS, respectively. In conclusion, AT-RvD1 demonstrated significant anti-inflammatory effects in bronchial epithelial cells that were stimulated with LPS or Dp, which provides new perspectives for therapeutic strategies to control inflammatory airway diseases.

The anti-inflammatory and pro-resolution effects of aspirin-triggered RvD1 (AT-RvD1) on peripheral blood mononuclear cells from patients with severe asthma.

Asthma is an inflammatory disease that is characterized by a predominance of eosinophils and/or neutrophils in the airways. In the resolution of inflammation, lipid mediators such as resolvin D1 (RvD1) and its epimer aspirin-triggered RvD1 (AT-RvD1) are produced and demonstrate anti-inflammatory and pro-resolution effects. In experimental models such as airway allergic inflammation induced by ovalbumin in mice, RvD1 and AT-RvD1 alleviate some of the most important phenotypes of asthma. Here, we demonstrated the effects of AT-RvD1 on peripheral blood mononuclear cells (PBMCs) from healthy individuals and patients with severe asthma stimulated with lipopolysaccharide (LPS) or Dermatophagoides pteronyssinus (DM). AT-RvD1 (100nM) reduced the concentration of TNF-α in PBMCs from healthy individuals and patients with severe asthma stimulated with LPS or DM. In addition, AT-RvD1 lowered the production of IL-10 only in PBMCs from patients with severe asthma stimulated with LPS. These effects were associated in part with decreasing NF-κB activation. Moreover, AT-RvD1 significantly increased phagocytosis of apoptotic neutrophils by monocytes from patients with severe asthma. In conclusion, AT-RvD1 demonstrated both anti-inflammatory and pro-resolution effects in PBMCs from patients with severe asthma and could become in the future an alternative treatment for asthma.

AT-RvD1 modulates CCL-2 and CXCL-8 production and NF-κB, STAT-6, SOCS1, and SOCS3 expression on bronchial epithelial cells stimulated with IL-4.

Bronchial epithelial cells represent the first line of defense against microorganisms and allergens in the airways and play an important role in chronic inflammatory processes such as asthma. In an experimental model, both RvD1 and AT-RvD1, lipid mediators of inflammation resolution, ameliorated some of the most important phenotypes of experimental asthma. Here, we extend these results and demonstrate the effect of AT-RvD1 on bronchial epithelial cells (BEAS-2B) stimulated with IL-4. AT-RvD1 (100 nM) decreased both CCL2 and CXCL-8 production, in part by decreasing STAT6 and NF-κB pathways. Furthermore, the effects of AT-RvD1 were ALX/FRP2 receptor dependent, as the antagonist of this receptor (BOC1) reversed the inhibition of these chemokines by AT-RvD1. In addition, AT-RvD1 decreased SOCS1 and increased SOCS3 expression, which play important roles in Th1 and Th17 modulation, respectively. In conclusion, AT-RvD1 demonstrated significant effects on the IL-4-induced activation of bronchial epithelial cells and consequently the potential to modulate neutrophilic and eosinophilic airway inflammation in asthma. Taken together, these findings identify AT-RvD1 as a potential proresolving therapeutic agent for allergic responses in the airways.

Potential effects of medicinal plants and secondary metabolites on acute lung injury.

Acute lung injury (ALI) is a life-threatening syndrome that causes high morbidity and mortality worldwide. ALI is characterized by increased permeability of the alveolar-capillary membrane, edema, uncontrolled neutrophils migration to the lung, and diffuse alveolar damage, leading to acute hypoxemic respiratory failure. Although corticosteroids remain the mainstay of ALI treatment, they cause significant side effects. Agents of natural origin, such as medicinal plants and their secondary metabolites, mainly those with very few side effects, could be excellent alternatives for ALI treatment. Several studies, including our own, have demonstrated that plant extracts and/or secondary metabolites isolated from them reduce most ALI phenotypes in experimental animal models, including neutrophil recruitment to the lung, the production of pro-inflammatory cytokines and chemokines, edema, and vascular permeability. In this review, we summarized these studies and described the anti-inflammatory activity of various plant extracts, such as Ginkgo biloba and Punica granatum, and such secondary metabolites as epigallocatechin-3-gallate and ellagic acid. In addition, we highlight the medical potential of these extracts and plant-derived compounds for treating of ALI.