Lung Inflammation In Patients Research Articles

Inflammatory Activity of Epithelial Stem Cell Variants from Cystic Fibrosis Lungs Is Not Resolved by CFTR Modulators.

Rationale: CFTR (cystic fibrosis transmembrane conductance regulator) modulator drugs restore function to mutant channels in patients with cystic fibrosis (CF) and lead to improvements in body mass index and lung function. Although it is anticipated that early childhood treatment with CFTR modulators will significantly delay or even prevent the onset of advanced lung disease, lung neutrophils and inflammatory cytokines remain high in patients with CF with established lung disease despite modulator therapy, underscoring the need to identify and ultimately target the sources of this inflammation in CF lungs. Objectives: To determine whether CF lungs, like chronic obstructive pulmonary disease (COPD) lungs, harbor potentially pathogenic stem cell "variants" distinct from the normal p63/Krt5 lung stem cells devoted to alveolar fates, to identify specific variants that might contribute to the inflammatory state of CF lungs, and to assess the impact of CFTR genetic complementation or CFTR modulators on the inflammatory variants identified herein. Methods: Stem cell cloning technology developed to resolve pathogenic stem cell heterogeneity in COPD and idiopathic pulmonary fibrosis lungs was applied to end-stage lungs of patients with CF (three homozygous CFTR:F508D, one CFTR F508D/L1254X; FEV1, 14-30%) undergoing therapeutic lung transplantation. Single-cell-derived clones corresponding to the six stem cell clusters resolved by single-cell RNA sequencing of these libraries were assessed by RNA sequencing and xenografting to monitor inflammation, fibrosis, and mucin secretion. The impact of CFTR activity on these variants after CFTR gene complementation or exposure to CFTR modulators was assessed by molecular and functional studies. Measurements and Main Results: End-stage CF lungs display a stem cell heterogeneity marked by five predominant variants in addition to the normal lung stem cell, of which three are proinflammatory both at the level of gene expression and their ability to drive neutrophilic inflammation in xenografts in immunodeficient mice. The proinflammatory functions of these three variants were unallayed by genetic or pharmacological restoration of CFTR activity. Conclusions: The emergence of three proinflammatory stem cell variants in CF lungs may contribute to the persistence of lung inflammation in patients with CF with advanced disease undergoing CFTR modulator therapy.

Deficient Radiation Transcription Response in COVID-19 Patients

The ongoing SARS-CoV-2 pandemic has resulted in over 6.3 million deaths and 560 million COVID-19 cases worldwide. Clinical management of hospitalized patients is complex due to the heterogeneous course of COVID-19. Low-dose radiation therapy is known to dampen localized chronic inflammation and has been suggested to be used to reduce lung inflammation in patients with COVID-19. However, it is unknown whether SARS-CoV-2 alters the radiation response and associated radiation exposure related risk. We generated gene expression profiles from circulating leukocytes of hospitalized patients with COVID-19 and healthy donors. The p53 signaling pathway was found to be dysregulated, with mRNA levels of p53, ATM, and CHK2 being lower in patients with COVID-19. Several key p53 target genes involved in cell cycle arrest, apoptosis, and p53 feedback inhibition were upregulated in patients with COVID-19 while other p53 target genes were downregulated. This dysregulation has functional consequences as the transcription of p53-dependant genes (CCNG1, GADD45A, DDB2, SESN1, FDXR, APOBEC) was reduced 24 hours after x-ray exposure ex vivo to both low (100 mGy) or high (2 Gy) doses. SARS-CoV-2 infection affects a DNA damage response that may modify radiation-induced health risks in exposed patients with COVID-19.

Treatment of Alzheimer’s disease by modulation of microglial neuroinflammation by nasal anti‐CD3 mAb

AbstractBackgroundNeuroinflammation and microglial activation play a role in AD as shown pathologically and by microglial PET imaging (Zhou et al, Front Immunol 2021). We found that nasal anti‐CD3 mAb induced IL‐10‐secreting T cells in the cervical lymph node that migrate to the brain, suppress microglial inflammation and ameliorate disease in a model of progressive MS (Mayo et a,l Brain 2016). In humans we found that nasal anti‐CD3 (Foralumab) decreased inflammation and accelerated resolution of lung inflammation in patients with mild COVID‐19 (Moreira et al, Front Immunol 2021) and modulated microglial activation in progressive MS as measured by microglial PET imaging (Chitnis et al, unpublished). We thus tested nasal anti‐CD3 in animal models of AD.MethodWe treated AD mice (3xTg and APP/PS1) with nasal anti‐CD3, isotype control antibody or PBS 3x/week for 6 months (3xTg) or 3x/week for 2 months (APP/PS1) and investigated cognitive behavior (Morris water maze and Y‐maze), microglia gene profile using a Nanostring myeloid codeset and T cell infiltration in the brain by immunofluorescence.ResultWe found that microglia lose their homeostatic (M0) signature and acquire a neurodegenerative (MGnD) signature in animal models of AD. In 3xTg mice, we found that nasal anti‐CD3 restored the M0 signature by increasing the expression of Cx3cr1, Mafb, and Jun, and lessened the MGnD signature by decreasing the expression of Trem2, Nos2 and Ccl5. Nasal anti‐CD3 improved cognition in 3xTg mice as measured by the Y‐maze and Morris water maze tests and in APP/PS1 mice as measured by the Y‐maze test. Nasal anti‐CD3 induced migration of T cells to the brain which interacted with microglia.ConclusionNasal anti‐CD3 restores the microglial M0 signature and improves behavior in animal models of AD. Based on these results and the successful administration of nasal anti‐CD3 to subjects with progressive MS and COVID‐19, phase 1 trials of nasal Foralumab are planned in subjects with mild AD to assess safety, clinical effects and microglial activation as measured by microglial PET imaging. Nasal anti‐CD3 is a novel approach to treat AD by targeting microglial inflammation.

D-dimers-"Normal" Levels versus Elevated Levels Due to a Range of Conditions, Including "D-dimeritis," Inflammation, Thromboembolism, Disseminated Intravascular Coagulation, and COVID-19.

D-dimers reflect a breakdown product of fibrin. The current narrative review outlines how D-dimers can arise in normal individuals, as well as in patients suffering from a wide range of disease states. D-dimers in normal individuals without evident thrombosis can arise from background fibrinolytic activity in various tissues, including kidney, mammary and salivary glands, which ensures smooth flow of arising fluids where any blood contamination could be immediately lysed. In addition, healthy individuals can also regularly sustain minor injuries, often unbeknown to them, and wound healing follows clot formation in these situations. D-dimers can also arise in anxiety and following exercise, and are also markers of inflammation. Lung inflammation (triggered by microbes or foreign particles) is perhaps also particularly relevant, since the hemostasis system and fibrinolysis help to trap and remove such debris. Lung inflammation in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may contribute to D-dimer levels additive to thrombosis in patients with COVID-19 (coronavirus disease 2019). Indeed, severe COVID-19 can lead to multiple activation events, including inflammation, primary and secondary hemostasis, and fibrinolysis, all of which may contribute to cumulative D-dimer development. Finally, D-dimer testing has also found a role in the diagnosis and triaging of the so-called (COVID-19) vaccine-induced thrombotic thrombocytopenia.

Radioresistant cells in STING gain-of-function mice initiate lymphocyte dependent lung inflammation and IFNγ dependent mortality

Abstract Pediatric patients with gain-of-function (GOF) mutations in the cytosolic dsDNA sensing adaptor STING develop an autoinflammatory syndrome known as STING Associated Vasculopathy with onset in Infancy (SAVI). SAVI patients show elevated interferon signature genes and suffer from interstitial lung disease (ILD) with lymphocyte predominate bronchus associated lymphoid tissue (BALT). We genetically engineered SAVI mice (STING V154M or VM) that recapitulates human disease, including lymphocyte rich ILD, and found by genetic ablation that lymphocytes are required for lung pathology. However, while ablation of either T or B lymphocytes prolongs survival, lung immune aggregates persist, indicating either can independently be recruited as BALT. Using radiation chimeras, we found that hematopoietic stem cell (HSC) derived STING GOF was neither sufficient nor required for VM lung disease, suggesting a role for lung radioresistant parenchymal and stromal cell STING GOF in SAVI. We identified lung endothelia as putative radioresistant cells which express STING and confirmed expression by IF microscopy and FACS. FACS analysis also revealed SAVI lung endothelia upregulate MHCII, but only when sufficient for IFNgR. VM T cells produce IFNg, and IFNgR deficiency was sufficient to prevent endothelial MHCII upregulation and attenuate mortality. However, HSC STING GOF was not required for endothelial MHCII upregulation, suggesting stromal intrinsic STING GOF initiates this outcome. These findings suggest that activation of STING in stromal and parenchymal cells play a key role the initiation of lung inflammation in patients with connective tissue disease ILD. Supported by: T32 GM107000 (MSTP); T32 AI132152 (KMG); F30 HL154674 (KMG); AI128358 (AMR/KAF); Lupus Research Alliance

The Cholinergic and ACE-2-Dependent Anti-Inflammatory Systems in the Lung: New Scenarios Emerging From COVID-19.

The renin angiotensin system and the cholinergic anti-inflammatory pathway have been recently shown to modulate lung inflammation in patients with COVID-19. We will show how studies performed on this disease are starting to provide evidence that these two anti-inflammatory systems may functionally interact with each other, a mechanism that could have a more general physiological relevance than only COVID-19 infection.

Chest Computed Tomography (CT) Severity Scales in COVID-19 Disease: A Validation Study.

BackgroundImaging-based quantitative assessment of lung lesions plays a key role in patient triage and therapeutic decision-making processes. The aim of our study was to validate the Total Severity Score (TSS), Chest Computed Tomography Score (CT-S), and Chest CT Severity Score (CT-SS) scales, which were used to assess the extent of lung inflammation in patients with SARS-CoV-2 infection in terms of interobserver agreement and the correlation of scores with patient clinical condition on the day of the study.Material/MethodsA total of 77 chest CT scans collected from 77 consecutive patients hospitalized because of SARS-CoV-2 were included. The scans were assessed independently by 2 radiologists aware of the patients’ positive results of RT-PCR tests. Each chest CT was assessed according to the 3 scales. To assess the interobserver agreement of CT scan assessments, Cohen’s κ and intraclass correlation coefficient (ICC) were calculated.ResultsFor the overall assessment, the κ was 0.944 and the ICC was 0.948 for the TSS; the κ was 0.909 and the ICC was 0.919 for the CT-S; and the κ was 0.888 and the ICC was 0.899 for the CT-SS. The CT-SS (r=0.627 for Radiologist 1 and r=0.653 for Radiologist 2) revealed the strongest positive correlation with the patient clinical condition as expressed using the Modified Early Warning Score.ConclusionsThe interobserver agreement for the 3 evaluated scales was very good. The CT-SS was found to have the strongest positive relationship with the Modified Early Warning Score.

Chronic infection by nontypeable Haemophilus influenzae fuels airway inflammation.

Nontypeable Haemophilus influenzae (NTHi) is commonly isolated from airways of patients suffering from chronic respiratory diseases, such as COPD or cystic fibrosis (CF). However, to what extent NTHi long-term infection contributes to the lung inflammatory burden during chronic airway disease is still controversial.Here, we exploited human respiratory samples from a small cohort of CF patients and found that patients chronically infected with NTHi had significantly higher levels of interleukin (IL)-8 and CXCL1 than those who were not infected. To better define the impact of chronic NTHi infection in fuelling inflammatory response in chronic lung diseases, we developed a new mouse model using both laboratory and clinical strains. Chronic NTHi infection was associated with chronic inflammation of the lung, characterised by recruitment of neutrophils and cytokine release keratinocyte-derived chemokine (KC), macrophage inflammatory protein 2 (MIP-2), granulocyte colony-stimulating factor (G-CFS), IL-6, IL-17A and IL-17F) at 2 and 14 days post-infection. An increased burden of T-cell-mediated response (CD4+ and γδ cells) and higher levels of pro-matrix metalloproteinase 9 (pro-MMP9), known to be associated with tissue remodelling, were observed at 14 days post-infection. Of note we found that both CD4+IL-17+ cells and levels of IL-17 cytokines were enriched in mice at advanced stages of NTHi chronic infection. Moreover, by immunohistochemistry we found CD3+, B220+ and CXCL-13+ cells localised in bronchus-associated lymphoid tissue-like structures at day 14.Our results demonstrate that chronic NTHi infection exerts a pro-inflammatory activity in the human and murine lung and could therefore contribute to the exaggerated burden of lung inflammation in patients at risk.

Effect of extrafine formulation of BDP/FF inhaler on asthma control, small airway function and airway inflammation among Mexican asthmatic patients. A retrospective analysis.

Asthma, an inflammatory disease affecting more than 300 million patients in the world. Small airways are by far bigger than the large airway's one and constitutes the area most affected by asthma. Reaching the small airways represents a challenge for treatments because of the dimensions and structure of the bronchial lumen. Inhaled extrafine (ExF) combinations are needed to reach and treat them. This study aimed to assess the effect of extrafine Beclometasone dipropionate/Formoterol fumarate (BDP/FF) in the control of symptoms, lung function and lung inflammation in patients with asthma. Retrospective study, carried out in 62 Mexican patients diagnosed with asthma and treated with two inhalations twice daily of ExF BDP/FF 100/6μg (via pMDI) and with an Asthma Control Test (ACT) score ≤19 points. Moreover, from patient's files, we analysed ACT score, Impulse Oscillometry (IOS) and Fractional exhaled Nitric Oxide (FeNO) both from their first consultation (baseline) and after one month of therapy. BDP/FF 100/6μg ExF showed that ACT, 79% of patients achieved control of disease (ACT≥20 points) and 14.5% of patients achieved total control of the disease (ACT=25 points); Oscillometry values R5- R20 diminished by 41%, X5 by 18.1% and AX by 56.5% and FeNO decreased by 52% after one month of treatment. BDP/FF 100/6μg extrafine improved asthma control after one month of treatment, and this was sustained for 3 months. Likewise, both the lung function, measured by IOS and inflammatory state, measured by FeNO, also significantly improved.

Severe Coronavirus disease 2019 successfully treated with glucocorticoid and high-dose intravenous immunoglobulin: A case report and analysis of clinical experience

Objective To report a case of severe Coronavirus disease 2019 (COVID-19) that had been successfully treated with glucocorticoid and intravenous immunoglobulin therapy. Methods and results The patient was a healthcare provider in Wuhan City who was taking care of COVID-19 patients before the onset of the disease. He started to cough with a little white sticky sputum on January 16, 2020 and had a fever on January 22 (up to 38.5 ℃) before admission. CT results showed mild exudation in both lungs. Oral oseltamivir and intravenous moxifloxacin, cefoperazone and sulbactam sodium were given in addition to nutritional support. On January 26, the patient had chest tightness and shortness of breath. A swab test was positive for severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) nucleic acid, and chest CT results showed moderate exudation in both lungs. On January 28, shortness of breath worsened and intravenous methylprednisolone (40 mg, qd) and immunoglobulin (10 g, qd) were given. On January 30, shortness of breath further worsened;he had a body temperature of 40.7 ℃, pulse oxygen saturation (SpO2) of 83% with oxygen inhalation at 10 L/min, and lymphocyte count of 0.5×109/L. The dose of methylprednisolone and immunoglobulin were adjusted to 40 mg, q12h and 20 g, qd, respectively. Subcutaneous injection of thymalfasin (1.6 mg, qd) was added. Then the body temperature returned to normal, and symptoms such as chest tightness and shortness of breath were gradually improved. On January 31, SpO2 was 88% with oxygen inhalation at 10 L/min and a chest CT results revealed large amount of exudation in both lungs. On February 2, SpO2 was 95% with oxygen inhalation at 5 L/min and the dose of methylprednisolone was then gradually reduced. A chest CT results on February 3 revealed improved lung inflammation, and a throat swab on February 4 and 9 was negative for SARS-CoV-2 nucleic acid. Conclusion Glucocorticoid should be used with caution in patients with early and mild COVID-19. However, appropriate dosage of glucocorticoid can be used to modulate lung inflammation in patients with decompensated respiratory failure. Additionally, large dose of immunoglobulin can be given if necessary.

Clinical Pearls.

Many evidence-based practice (EBP) protocols are used in the care of critical care patients; however, the speed of translation of these protocols into practice can be long, potentially affecting the quality of that care. Although research has shown that specific nurse credentials improve patients’ outcomes, it is not known how these credentials are associated with the adoption of EBP.Gigli and colleagues conducted a survey to examine the relationship between nurses’ education level and certification status and their psychosocial beliefs, knowledge of EBP, and perceived value in EBP. They foundThe findings support the value of nurses with specialty credentialing. The authors recommend that institutions seeking adoption of EBP support nurse credentialing as a means to improve intensive care.See Article, pp e1–e12Sepsis remains a substantial health care challenge, with recent costs surpassing $23 million annually. Although the most common type of infection leading to sepsis is pneumonia, preventive efforts have focused primarily on ventilator-associated pneumonia (VAP). However, morbidity and mortality with nonventilator hospital-acquired pneumonia (NV-HAP) are significant.Giuliano and colleagues explored demographic and clinical characteristics of adult patients from a national inpatient dataset and found thatRecognition and treatment of NV-HAP has been underappreciated, thus increasing the risk for sepsis and other complications. The authors suggest additional research to turn successful VAP prevention into strategies for NV-HAP prevention.See Article, pp 9–14It has long been known that high tidal volumes and high airway pressures can damage the lungs of patients with acute respiratory disease. However, little study has addressed the effects of these mechanical ventilator settings on normal lungs.Ziaka and colleagues compared 2 ventilation strategies—low tidal volume (6 mL/kg) and high tidal volume (12 mL/kg)—on biomarkers of inflammation measured in exhaled breath condensate in patients with normal lungs. They found thatFindings indicate large tidal volume with mechanical ventilation may increase the risk for lung inflammation in patients without preexisting lung injury. Further study is warranted with more detailed mechanics of ventilation.See Article, pp 15–21Ethical conflicts occur for a number of reasons and can cause distress and anxiety for patients and families. Communication problems between the patient/family and health care providers on medical decision-making and treatment goals are a primary source of ethical conflicts in the intensive care unit. Unfortunately, little research has addressed the impact of team-based interventions for prevention of such conflicts.Pavlish and colleagues evaluated the use of a proactive, team-based intervention with 3 parts: (1) daily completion of early action protocol, (2) interactive case-based protocol orientation, and (3) an ethics application. They found the following:Using a routine, team-based intervention can improve communication between patients’ families and health care providers, resulting in improved goal clarification, care coordination, and identification of early action needs.See Article, pp 49–58

Rhinovirus-induces progression of lung disease in a mouse model of COPD via IL-33/ST2 signaling axis.

Rhinovirus (RV), which is associated with acute exacerbations, also causes persistent lung inflammation in patients with chronic obstructive pulmonary disease (COPD), but the underlying mechanisms are not well-known. Recently, we demonstrated that RV causes persistent lung inflammation with accumulation of a subset of macrophages (CD11b+/CD11c+), and CD8+ T cells, and progression of emphysema. In the present study, we examined the mechanisms underlying the RV-induced persistent inflammation and progression of emphysema in mice with COPD phenotype. Our results demonstrate that at 14 days post-RV infection, in addition to sustained increase in CCL3, CXCL-10 and IFN-γ expression as previously observed, levels of interleukin-33 (IL-33), a ligand for ST2 receptor, and matrix metalloproteinase (MMP)12 are also elevated in mice with COPD phenotype, but not in normal mice. Further, MMP12 was primarily expressed in CD11b+/CD11c+ macrophages. Neutralization of ST2, reduced the expression of CXCL-10 and IFN-γ and attenuated accumulation of CD11b+/CD11c+ macrophages, neutrophils and CD8+ T cells in COPD mice. Neutralization of IFN-γ, or ST2 attenuated MMP12 expression and prevented progression of emphysema in these mice. Taken together, our results indicate that RV may stimulate expression of CXCL-10 and IFN-γ via activation of ST2/IL-33 signaling axis, which in turn promote accumulation of CD11b+/CD11c+ macrophages and CD8+ T cells. Furthermore, RV-induced IFN-γ stimulates MMP12 expression particularly in CD11b+/CD11c+ macrophages, which may degrade alveolar walls thus leading to progression of emphysema in these mice. In conclusion, our data suggest an important role for ST2/IL-33 signaling axis in RV-induced pathological changes in COPD mice.

Relevance of interferon-gamma in pathogenesis of life-threatening rapidly progressive interstitial lung disease in patients with dermatomyositis

BackgroundDermatomyositis (DM) with rapidly progressive interstitial lung disease (DM RP-ILD) is a life-threatening condition. Serum cytokine levels are potentially suitable biomarkers for DM RP-ILD. However, the relationships among cytokine levels, lung imaging findings, and lung pathology have not been investigated. The aim of the present retrospective study was to determine the association between hypercytokinemia and lung inflammation in patients with DM RP-ILD.MethodsThe study subjects were nine patients with life-threatening DM RP-ILD and severe hypoxemia (partial arterial oxygen pressure (PaO2)/fraction of inspired oxygen (FiO2) ratio ≤ 200) before receiving intensive care management, who were admitted to our hospital between 2006 and 2015. The controls included 10 patients with DM without RP-ILD and 19 healthy subjects. We assessed the association between serum cytokine levels and computed tomography (CT) scores of the lung (ground glass opacity-score, G-score; fibrosis-score, F-score). Lung, hilar lymph nodes, and spleen from two autopsies were examined by hematoxylin-eosin (H&E) staining and immunostaining.ResultsSerum interferon (IFN)-γ, interleukin (IL)-1β and IL-12 levels were significantly higher in patients with DM RP-ILD than in the other two groups, whereas serum IL-6 levels were elevated in the two patient groups but not in the healthy subjects. Serum levels of IL-2, IL-4, IL-8, IL-10, IFN-α, and TNF (tumor necrosis factor)-α were not characteristically elevated in the DM RP-ILD group. Serum IFN-γ levels correlated with G-scores in patients with DM RP-ILD, while IL-1β was negatively correlation with F-scores. Immunohistochemical staining showed infiltration of numerous IFN-γ-positive histiocytes in the lung and hilar lymph nodes; but not in the spleen. Serum IL-6 levels did not correlate with the CT scores. Numerous IL-6-positive plasma cells were found in hilar lymph nodes, but not in the lungs or spleen.ConclusionsOur results suggest strong IFN-γ-related immune reaction in the lungs and hilar lymph nodes of patients with life-threatening DM RP-ILD, and potential IFN-γ involvement in the pathogenesis of DM, specifically in the pulmonary lesions of RP-ILD.

Inhaled calcium salts inhibit tobacco smoke-induced inflammation by modulating expression of chemokines and cytokines

Tobacco smoke-induced lung inflammation in patients with chronic obstructive pulmonary disease (COPD) worsens with disease progression and acute exacerbations caused by respiratory infections. Chronic therapies to manage COPD center on bronchodilators to improve lung function and inhaled corticosteroids (ICS) to help reduce the risk of exacerbations. Novel therapies are needed that reduce the underlying inflammation associated with COPD and the inflammation resulting from respiratory infections that worsen disease. The lung is lined with airway surface liquid (ASL), a rheologically active material that provides an innate defense for the airway against inhaled particulate and is continuously cleared from the airways by mucociliary clearance. The rheological properties of the ASL can be altered by changes in airway hydration and by cations, such as calcium, that interact with electronegative glycoproteins. The effect of inhaled salts on inflammation resulting from tobacco smoke exposure was studied to determine if cations could be used to alter the properties of the ASL and reduce inflammation. Inhaled calcium salts, but not sodium or magnesium salts, reduced cellular inflammation and key chemokines and cytokines that were induced by tobacco smoke exposure. Similar anti-inflammatory effects of calcium salts were observed using in vitro cultures of human monocyte derived macrophages and human bronchial epithelial cells. The data suggest that inhaled calcium salts may act broadly on both biophysical and biological pathways to reduce pulmonary inflammation.

Regulation of the NLRP3 inflammasome and macrophage pyroptosis by the p38 MAPK signaling pathway in a mouse model of acute lung injury.

Acute lung injury and acute respiratory distress syndrome (ALI/ARDS) is characterized by uncontrolled progressive lung inflammation. Macrophages serve a key role in the pathogenesis of ALI/ARDS. Macrophage pyroptosis is a process of cell death releasing the proinflammatory cytokines interleukin (IL)-1β and IL-18. It was hypothesized that macrophage pyroptosis may partially account for the uncontrolled lung inflammation of ALI/ARDS. In the present study, greater macrophage pyroptosis in lipopolysaccharide (LPS)-treated macrophages and the ALI/ARDS mouse model was observed. The expression of nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing (NLRP)3 and IL-1β and cleavage of caspase-1 were significantly elevated following LPS treatment accompanied by greater activation of p38 mitogen-activated protein kinase (MAPK) signaling in vitro and in vivo. However, blocking p38 MAPK signaling through the inhibitor SB203580 significantly suppressed the acute lung injury and excessive lung inflammation in vivo, consistent with the reduced expression of the NLRP3 inflammasome and IL-1β and cleavage of caspase-1. Pretreatment of the rat NR8383 macrophage cell line with SB203580 significantly decreased the population of caspase-1+PI+ pyroptotic cells and expression of NLRP3/IL-1β. However, a larger population of Annexin V+PI- apoptotic cells was observed following blocking of the p38 MAPK signaling pathway. The results indicated that blockage of p38 MAPK signaling pathway skewed macrophage cell death from proinflammatory pyroptosis towards non-inflammatory apoptosis. These effects may contribute to attenuated acute lung injury and excessive inflammation in the SB203580-treated mice. The results may provide a novel therapeutic strategy for the treatment of uncontrolled lung inflammation in patients with ALI/ARDS.

Possible Role of IL-25 in Eosinophilic Lung Inflammation in Patients with Chronic Eosinophilic Pneumonia.

Interleukin (IL)-25 and IL-33 induce IL-5 production by various types of cells, such as type 2 helper T (Th2) cells and type 2 innate lymphoid cells. The number of Th2 cells and concentration of IL-5 in the bronchoalveolar lavage fluid (BALF) are increased in patients with eosinophilic pneumonia (EP). To examine the contribution of IL-25 and IL-33 to eosinophilic inflammation of the lung in humans, we evaluated IL-5, IL-25 and IL-33 levels in the BALF of patients with EP. IL-5, IL-25, and IL-33 concentrations in the BALF were measured by enzyme-linked immunosorbent assay in patients with acute eosinophilic pneumonia (AEP), chronic eosinophilic pneumonia (CEP), idiopathic pulmonary fibrosis (IPF), and sarcoidosis. The absolute number of eosinophils, and IL-5 levels, but not IL-33 levels, in the BALF were significantly higher in patients with EP than in patients with IPF and sarcoidosis. IL-25 levels in the BALF were significantly higher in patients with CEP, but not in patients with AEP, than in patients with IPF and sarcoidosis. The absolute number of eosinophils was significantly correlated with the IL-5 concentration in the BALF of patients with EP. IL-5 concentrations were significantly correlated with IL-25 concentrations in the BALF of patients with CEP, but not in patients with AEP. IL-5 levels were not correlated with IL-33 levels in the BALF of patients with EP. Our findings suggest that IL-25 plays an important role via IL-5 in eosinophilic lung inflammation in patients with CEP.

NTPDase1/CD39 and aberrant purinergic signalling in the pathogenesis of COPD.

Purinergic receptor activation via extracellular ATP is involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). Nucleoside triphosphate diphosphohydrolase-1/CD39 hydrolyses extracellular ATP and modulates P2 receptor signalling.We aimed to investigate the expression and function of CD39 in the pathogenesis of cigarette smoke-induced lung inflammation in patients and preclinical mouse models. CD39 expression and soluble ATPase activity were quantified in sputum and bronchoalveolar lavage fluid (BALF) cells in nonsmokers, smokers and COPD patients or mice with cigarette smoke-induced lung inflammation. In mice, pulmonary ATP and cytokine concentrations, inflammation and emphysema were analysed in the presence or absence of CD39.Following acute cigarette smoke exposure CD39 was upregulated in BALF cells in smokers with further increases in COPD patients. Acute cigarette smoke exposure induced CD39 upregulation in murine lungs and BALF cells, and ATP degradation was accelerated in airway fluids. CD39 inhibition and deficiency led to augmented lung inflammation; treatment with ATPase during cigarette smoke exposure prevented emphysema.Pulmonary CD39 expression and activity are increased in COPD. CD39 deficiency leads to enhanced emphysema in mice, while external administration of a functional CD39 analogue partially rescues the phenotype. The compensatory upregulation of pulmonary CD39 might serve as a protective mechanism in cigarette smoke-induced lung damage.

Myeloid-Specific Fos-Related Antigen-1 Regulates Cigarette Smoke–Induced Lung Inflammation, Not Emphysema, in Mice

Heightened lung inflammation is a cardinal feature of chronic obstructive pulmonary disease (COPD). Cigarette smoke (CS)-induced macrophage recruitment and activation, accompanied by abnormal secretion of a number of inflammatory cytokines and matrix metalloproteinases, play a major role in the pathophysiology of COPD. The Fos-related antigen-1 (Fra-1) transcription factor differentially regulates several cellular processes that are implicated in COPD, such as inflammation and immune responses, cell proliferation and death, and extracellular remodeling. Although CS stimulates Fra-1 expression in the lung, the precise role of this transcription factor in the regulation of CS-induced lung inflammation in vivo is poorly understood. Here, we report that myeloid-specific Fra-1 signaling is important for CS-induced lung macrophagic inflammatory response. In response to chronic CS exposure, mice with Fra-1 specifically deleted in myeloid cells showed reduced levels of CS-induced lung macrophagic inflammation, accompanied by decreased expression levels of proinflammatory cytokines compared with their wild-type counterparts. Consistent with this result, bone marrow-derived Fra-1-null macrophages treated with CS showed decreased levels of proinflammatory mediators and matrix metalloproteinases. Interestingly, deletion of Fra-1 in myeloid cells did not affect the severity of emphysema. We propose that Fra-1 plays a key role in promoting chronic CS-induced lung macrophagic inflammation in vivo, and that targeting this transcription factor may be useful in dampening persistent lung inflammation in patients with COPD.

A Th17- and Th2-skewed Cytokine Profile in Cystic Fibrosis Lungs Represents a Potential Risk Factor forPseudomonas aeruginosaInfection

Cystic fibrosis (CF) is characterized by progressive pulmonary inflammation that is infection-triggered. Pseudomonas aeruginosa represents a risk factor for deterioration of lung function and reduced life expectancy. To assess T-cell cytokine/chemokine production in clinically stable children with CF and evaluate the association between T-cell subtypes and susceptibility for infection with P. aeruginosa. T-cell cytokine/chemokine profiles were measured in bronchoalveolar lavage fluid (BALF) from children with CF (n = 57; 6.1 ± 5.9 yr) and non-CF control subjects (n = 18; 5.9 ± 4.3 yr). Memory responses to Aspergillus fumigatus and P. aeruginosa were monitored. High-resolution computed tomography-based Helbich score was assessed. In a prospective observational trial the association between BALF cytokine/chemokine profiles and subsequent infection with P. aeruginosa was studied. Th1- (INF-γ), Th2- (IL-5, IL-13), Th17- (IL-17A), and Th17-related cytokines (IL-1β, IL-6) were significantly up-regulated in airways of patients with CF. IL-17A, IL-13, and IL-5 were significantly higher in BALF of symptomatic as compared with clinically asymptomatic patients with CF. IL-17A and IL-5 correlated with the percentage of neutrophils in BALF (r = 0.41, P < 0.05 and r = 0.46, P < 0.05, respectively). Th17- (IL-17A, IL-6, IL-1β, IL-8) and Th2-associated cytokines and chemokines (IL-5, IL-13, TARC/CCL17), but not IFN-γ levels, significantly correlated with high-resolution computed tomography changes (Helbich score; P < 0.05). P. aeruginosa- and A. fumigatus-specific T cells from patients with CF displayed significantly higher IL-5 and IL-17A mRNA expression. IL-17A and TARC/CCL17 were significantly augmented in patients that developed P. aeruginosa infection within 24 months. We propose a role for Th17 and Th2 T cells in chronic inflammation in lungs of patients with CF. High concentrations of these cytokines/chemokines in CF airways precede infection with P. aeruginosa.

Aspirin attenuates the anti-inflammatory effects of theophylline via inhibition of cAMP production in mice with non-eosinophilic asthma

Theophylline is commonly used to treat severe asthma and chronic obstructive pulmonary disease (COPD) characterized by non-eosinophilic inflammation. Acetyl salicylic acid (ASA) is one of the most widely used medications worldwide, but up to 20% of patients with asthma experience aggravated respiratory symptoms after taking ASA. Here we evaluated the adverse effect of ASA on the therapeutic effect of theophylline in mice with non-eosinophilic asthma. A non-eosinophilic asthma mouse model was induced by airway sensitization with lipopolysaccharide-containing allergen and then challenged with allergen alone. Therapeutic intervention was performed during allergen challenge. Theophylline inhibited lung inflammation partly induced by Th1 immune response. ASA attenuated the beneficial effects of theophylline. However, co-administration of the ASA metabolite salicylic acid (SA) showed no attenuating effect on theophylline treatment. The therapeutic effect of theophylline was associated with increase in cAMP levels, which was blocked by co-treatment of theophylline and ASA. ASA co-treatment also attenuated the anti-inflammatory effects of a specific phosphodiesterase 4 inhibitor. These results demonstrate that ASA reverses anti-inflammatory effects of theophylline, and that ASA exerts its adverse effects through the inhibition of cAMP production. Our data suggest that ASA reverses lung inflammation in patients taking theophylline, although clinical evidence will be needed.