Inflammation In Bronchoalveolar Lavage Research Articles

Breastfeeding in infants who aspirate may increase risk of pulmonary inflammation.

To evaluate management strategies and pulmonary outcomes for breastfed infants with oropharyngeal dysphagia. We performed a retrospective cohort study of breastfed infants diagnosed with oropharyngeal dysphagia with documented aspiration or laryngeal penetration on videofluoroscopic swallow study (VFSS). Medical records were reviewed for VFSS results and speech-language pathologist recommendations following VFSS, results of chest x-ray, results of bronchoalveolar lavage (BAL) within 1 year of VFSS, and aspiration-related hospitalizations occurring before or within 1 year of VFSS. Subjects were categorized as cleared or not cleared to breastfeed based on the VFSS. Proportions were compared with Chi-square and Fisher's exact tests and means with Student's t-tests. Seventy-six infants (4.7 ± 0.4 months old) were included; 50% (38) had aspiration and 50% (38) had laryngeal penetration. After VFSS, 70% (53) were cleared to breastfeed while 30% (23) were not cleared to breastfeed. Patients with aspiration were less likely to be cleared to breastfeed (p = .006); however, 55% (21/38) of those with aspiration were still cleared to breastfeed. Infants cleared to breastfeed had significantly more pulmonary hospitalizations (p = .04) and were also at increased risk of elevated neutrophil count (p = .02) and culture growth on BAL (p = .01). Significantly increased abnormal neutrophil count was also found in those cleared to breastfeed with laryngeal penetration (p = .01). Infants with oropharyngeal dysphagia counseled to continue breastfeeding had increased risk of BAL inflammation and more pulmonary hospitalizations compared to those that were told to stop breastfeeding.

Predictive power of chest radiography for infectious or inflammatory lung disease.

Children frequently present with chronic cough, recurrent respiratory infections, and dysphagia. These symptoms are poor predictors of significant inflammatory lung disease, such as from chronic aspiration. Bronchoalveolar lavage (BAL) is the gold standard for identification of lung infection and airway inflammation but is expensive and requires sedation. Chest X-rays (CXR) are inexpensive, low-radiation tests that do not require sedations and can document findings associated with infectious or inflammatory lung disease. The accuracy of CXR to predict or exclude infectious or inflammatory lung disease has not been directly evaluated and is unknown. Retrospective cohort of all pediatric patients who underwent FFB with BAL within 2weeks of a CXR. Blinded CXR images reviewed for findings consistent with inflammatory disease by two senior pediatric radiologists. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for CXR to identify significant inflammation and/or infection on BAL were calculated. Three hundred and forty-four subjects included. Two hundred and sixty-three had positive CXR (77%), 183 had inflammatory BAL (53%), and 110 had infection (32%). The sensitivity of CXR changes for BAL inflammation, infection, and either inflammation or infection was 84.7, 90.9, and 85.3, respectively. The PPV of CXR was 58.9, 38.0, and 59.7. The NPV of CXR was 65.0, 87.5, and 66.3. Although CXR are inexpensive, do not require sedation, and are of low radiation dose, the ability of an entirely normal CXR to exclude active inflammatory or infectious lung disease is limited.

Immunopathological Mechanisms of Bird-Related Hypersensitivity Pneumonitis.

Bird-related hypersensitivity pneumonitis (BRHP) is an interstitial lung disease induced by avian proteins. The immunopathological pathways involved in the disease are still unknown. This study assesses the cellular immune response and the cytokine pattern in a mouse model of BRHP. On days -3 and -1, mice were intraperitoneally sensitized with commercial pigeon serum (PS) or saline. Intranasal instillations with PS or saline were carried out on three consecutive days/week over either 3 weeks (Group 1) or 12 weeks (Group 2). Leukocyte and cytokine patterns in lung tissue and pulmonary inflammation in bronchoalveolar lavage (BAL) were analysed. Both groups presented increases in resident monocytes, interstitial macrophages and type 2 dendritic cells (DCs), but also reductions in inflammatory monocytes, alveolar macrophages and tolerogenic DCs compared with their control groups. Group 1 had increased levels of eosinophils and T cells with reductions in neutrophils and B cells, while Group 2 showed high levels of B cells. Both groups exhibited increases in Th1 and Th2 cytokines. Group 2 also showed increased levels of IL-23, a Th17 cytokine. Increased levels of neutrophils, eosinophils and lymphocytes were observed in BAL samples of both groups compared with controls. In the first stages of BRHP, there is a mixed Th1/Th2 immune response, while during the progression of the disease, although there is a Th1 response, the cytokine levels seem to indicate a switch towards a Th2/Th17 mixed response.

Mild-moderate equine asthma: A scoping review of evidence supporting the consensus definition

Current consensus defines mild-moderate equine asthma (mEA; previously inflammatory airway disease) by a hierarchy of indicators of lung pathology: cough, poor performance, increased tracheobronchial mucus, inflammatory bronchoalveolar lavage (BAL) cytology and pulmonary dysfunction. Exclusion criteria include fever, systemic disease, or increased resting respiratory effort. The aim of this review was to inform future research by identifying gaps, strengths and weaknesses in the current body of evidence supporting this consensus-proposed definition. Objectives were to critique evidence supporting the inclusion of each diagnostic indicator in the case definition, by summarising and evaluating evidence for its association with higher-level indicators of lung inflammation. Searches of three databases identified 2275 articles relating to mEA or its diagnostic indicators, from which 298 full-text articles were screened and 45 reviewed in full. Studies (n = 44) had been performed worldwide in clinics, hospitals, racetracks, yards or research herds, in 6092 horses. Studies were predominantly opportunistic observational (n = 13/44: 29.5%) or cross-sectional (n = 11/44; 25%). The median number of horses per study was 74. Where breed and use were reported most were Thoroughbreds (58.2%; 2730/4688) and racehorses (72.8%; n = 3960/5439). Domains rated as high risk of bias in almost 50% of articles were ‘study power’ and ‘masking’. Heterogeneity in clinical and laboratory measures precluded meta-analysis. Evidence was more consistent for certain pairwise relationships (e.g., between cough and tracheobronchial mucus) than others (e.g., BAL cytology and lung function). Findings highlight the need for increased standardisation of diagnostic methods and reporting to facilitate future systematic review and meta-analysis.

Local nebulization of 1\u03b1,25(OH)2D3 attenuates LPS-induced acute lung inflammation

BackgroundEvidence supports a critical role of vitamin D status on exacerbation in chronic obstructive pulmonary disease, indicating the need to avoid vitamin D deficiency in these patients. However, oral vitamin D supplementation is limited by the potential risk for hypercalcemia. In this study, we investigated if local delivery of vitamin D to the lungs improves vitamin D-mediated anti-inflammatory action in response to acute inflammation without inducing hypercalcemia.MethodsWe studied vitamin D sufficient (VDS) or deficient (VDD) mice in whom 1α,25(OH)2D3 (0.2 μg/kg) or a vehicle followed by lipopolysaccharide (LPS 25 µg) were delivered to the lung as a micro-spray.ResultsLocal 1α,25(OH)2D3 reduced LPS-induced inflammatory cells in bronchoalveolar lavage (BAL) in VDS (absolute number of cells: − 57% and neutrophils − 51% p < 0.01) and tended to diminish LPS-increased CXCL5 BAL levels in VDS (− 40%, p = 0.05) while it had no effect on CXCL1 and CXCL2 in BAL and mRNA in lung of VDS and VDD. It also significantly attenuated the increased IL-13 in BAL and lung, especially in VDD mice (− 41 and − 75%, respectively). mRNA expression of Claudin-18 in lung was significantly lower in VDS mice with local 1α,25(OH)2D3 while Claudin-3, -5 and -8 mRNA levels remained unchanged. Finally, in VDD mice only, LPS reduced lung mRNA expression of adhesion junction Zona-occludens-1, in addition to increasing uric acid and total protein in BAL, which both were prevented by local 1α,25(OH)2D3.ConclusionUnder normal levels of vitamin D, local 1α,25(OH)2D3 nebulization into the lung efficiently reduced LPS induction of inflammatory cells in BAL and slightly attenuated LPS-increase in CXCL5. In case of severe vitamin D deficiency, although local 1α,25(OH)2D3 nebulization failed to significantly minimize cellular inflammation in BAL at this dose, it prevented epithelial barrier leakage and damage in lung. Additional research is needed to determine the potential long-term beneficial effects of local 1α,25(OH)2D3 nebulization on lung inflammation.

Inflammation on bronchoalveolar lavage cytology is associated with decreased chronic lung allograft dysfunction-free survival.

Lung transplant recipients undergo bronchoalveolar lavage (BAL) to detect antecedents of chronic lung allograft dysfunction (CLAD), but routine assessment of BAL cytology is controversial. We hypothesized that inflammation on BAL cytology would predict CLAD-free survival. In a single-center retrospective cohort, associations between cytology results and clinical characteristics were compared using generalized-estimating equation-adjusted regression. The association between BAL inflammation and CLAD or death risk was assessed using time-dependent Cox models. In 3365 cytology reports from 451 subjects, inflammation was the most common finding (6.2%, 210 cases), followed by fungal forms (5.3%, 178 cases, including 24 cases of suspectedAspergillus). Inflammation on BAL cytology was more common in procedures for symptoms (8.5%) versus surveillance (3.2%, p<.001). Inflammation on cytology was associated with automated neutrophil and lymphocyte counts, acute cellular rejection, infection, and portended a 2.2-fold hazard ratio (CI1.2-4.0, p=.007) for CLAD or death.However, inflammation by cytology did not inform CLAD-free survival risk beyond automated BAL cell counts (p=.57). Inflammation on BAL cytology is clinically significant, suggesting acute rejection or infection and increased risk of CLAD or death. However, other indicators of allograft inflammation can substitute for much of the information provided by BAL cytology.

The blocking effect of the glycoprotein IIb/IIIa receptor in the mouse model of asthma

BackgroundIt is apparent that the interaction between platelets and eosinophils plays a critical role in the activation of allergic inflammation. We investigated whether blocking of the glycoprotein (GP) IIb/IIIa receptor can attenuate allergic inflammation and airway hyperresponsiveness through inhibition of platelet–eosinophil aggregation (PEA) in asthma.Methods BALB/c mice were sensitized by intraperitoneal injection of ovalbumin (OVA) on days 0 and 14, followed by 3 nebulized OVA challenges on days 28–30. On each challenge day, 5 mg/kg tirofiban was administered intraperitoneally 30 min before the challenge. Mice were assessed for airway hyperresponsiveness (AHR), airway inflammation, and the degree of PEA. Finally, the activation levels of platelets and eosinophils were evaluated.ResultsTirofiban treatment decreased AHR and eosinophilic inflammation in Bronchoalveolar Lavage (BAL) fluid. This treatment also reduced the levels of interleukin (IL)-4, IL-5, and IL-13 in BAL fluid and airway inflammatory cell infiltration in histological evaluation. Interestingly, the blocking of the GP IIb/IIIa receptor more reduced PEA in both blood and lung tissue of tirofiban-treated mice than in those of the positive control mice, and both eosinophilic and platelet activations were attenuated in tirofiban-treated mice.ConclusionsThe blocking of GP IIb/IIIa receptor with tirofiban can attenuate AHR and airway inflammation through the inhibition of PEA and activation.

The Pulmonary Microbiome after Lung Transplantation is Associated with Gastroesophageal Reflux Disease, Inflammation, and Allograft Dysfunction

<h3>Purpose</h3> The pulmonary microbiome modulates the immune milieu in the lung allograft and is in turn influenced by gastroesophageal reflux disease (GERD). Although GERD has been linked to a higher risk of chronic lung allograft dysfunction (CLAD), the underlying role of the allograft microbiome is unknown. We assessed the relationships between the post-transplant pulmonary microbiome, GERD, inflammation, and allograft dysfunction. <h3>Methods</h3> 24 GERD and 51 no-GERD patients, defined by pH-impedance probe, had bronchoalveolar lavage (BAL) obtained at 3, 6, 9, and 12 months post-transplant. A separate cohort of 18 patients who underwent Nissen fundoplication for GERD within the first year post-transplant had BAL obtained before and after surgery. BAL were analysed for microbial communities and inflammatory cytokines using 16S rRNA sequencing and immunoassays, respectively. <h3>Results</h3> Hierarchical clustering of all GERD and no-GERD samples by Bray-Curtis dissimilarity identified three distinct community state types (CST) (Figure A). CST1 was positively associated with GERD and enriched in <i>Prevotella</i> and <i>Veillonella</i>. CST2 was negatively associated with GERD and enriched in <i>Streptococcus</i>. CST3 was independent of GERD and enriched in <i>Pseudomonas</i> and <i>Staphylococcus</i>. Compared to other CSTs, CST3 was associated with a greater proportion of patients with BAL inflammation, concurrent acute decline in lung function at 3 months, and earlier CLAD onset. Patients with the greatest decrease in BAL inflammation post-Nissen also had decreases in bacterial load and density of <i>Prevotella</i> (Figure B). <h3>Conclusion</h3> Pulmonary microbiota after lung transplantation cluster into three CSTs which differ by their associations with GERD. CST3 may represent a GERD-independent state of microbial dysbiosis which promotes inflammation and allograft rejection. Anti-GERD surgery appears to decrease GERD-associated microbiota.

Responses to acute infection with SARS-CoV-2 in the lungs of rhesus macaques, baboons and marmosets.

Nonhuman primate (NHP) models will expedite therapeutics and vaccines for COVID-19 into clinical trials. We compared acute SARS-CoV-2 infection in young and old rhesus macaques and baboons and old marmosets. Macaques had clinical signs of viral infection, mild-to-moderate pneumonitis and extra-pulmonary pathologies; both age groups recovered in two weeks. Baboons had prolonged viral RNA shedding and substantially more lung inflammation compared with macaques. Inflammation in bronchoalveolar lavage (BAL) was increased in old versus young baboons. Using techniques like CT imaging, immunophenotyping, alveolar/peripheral cytokine responses and immunohistochemical analyses, we delineated cellular immune responses to SARS-CoV-2 infection in macaque and baboon lungs, including innate and adaptive immune cells and a prominent Type I-interferon response. Macaques developed T cell memory phenotype/responses and bystander cytokine production. Old macaques had lower titres of SARS-CoV-2-specific IgG antibody levels compared with young. Acute respiratory distress in macaques and baboons recapitulates the progression of COVID-19 in humans, making them suitable as models to test vaccines and therapies.

Cobalt exposure via skin alters lung immune cells and enhances pulmonary responses to cobalt in mice.

Cobalt has been associated with allergic contact dermatitis and occupational asthma. However, the link between skin exposure and lung responses to cobalt is currently unknown. We investigated the effect of prior dermal sensitization to cobalt on pulmonary physiological and immunological responses after subsequent challenge with cobalt via the airways. BALB/c mice received epicutaneous applications (25 μL/ear) with 5% CoCl2*6H2O (Co) or the vehicle (Veh) dimethyl sulfoxide (DMSO) twice; they then received oropharyngeal challenges with 0.05% CoCl2*6H2O or saline five times, thereby obtaining four groups: Veh/Veh, Co/Veh, Veh/Co, and Co/Co. To detect early respiratory responses noninvasively, we performed sequential in vivo microcomputed tomography (µCT). One day after the last challenge, we assessed airway hyperreactivity (AHR) to methacholine, inflammation in bronchoalveolar lavage (BAL), innate lymphoid cells (ILCs) and dendritic cells (DCs) in the lungs, and serum IgE. Compared with the Veh/Veh group, the Co/Co group showed increased µCT-derived lung response, increased AHR to methacholine, mixed neutrophilic and eosinophilic inflammation, elevated monocyte chemoattractant protein-1 (MCP-1), and elevated keratinocyte chemoattractant (KC) in BAL. Flow cytometry in the Co/Co group demonstrated increased DC, type 1 and type 2 conventional DC (cDC1/cDC2), monocyte-derived DC, increased ILC group 2, and natural cytotoxicity receptor-ILC group 3. The Veh/Co group showed only increased AHR to methacholine and elevated MCP-1 in BAL, whereas the Co/Veh group showed increased cDC1 and ILC2 in lung. We conclude that dermal sensitization to cobalt may increase the susceptibility of the lungs to inhaling cobalt. Mechanistically, this enhanced susceptibility involves changes in pulmonary DCs and ILCs.

The immunomodulatory effects of diesel exhaust particles in asthma

Ammonium persulfate (AP) causes occupational asthma (OA) and diesel exhaust particles (DEP) exacerbate asthma; however, the role of DEP in asthma due to chemical agents has not been assessed to date. Therefore, the present work aims to study the immunomodulatory effects of DEP in a mouse model of chemical asthma. BALB/c ByJ mice were randomly divided into four experimental groups. On days 1 and 8, mice were dermally sensitized with AP or saline. On days 15, 18 and 21, they received intranasal instillations of AP or saline. Two experimental groups received DEP on every of the three challenges. Airway hyperresponsiveness (AHR), lung mechanics, pulmonary inflammation in bronchoalveolar lavage, leukocyte numbers in total lung tissue, oxidative stress and optical projection tomography (OPT) studies were assessed. The AP-sensitized and challenged group showed asthma-like responses, such as airway hyperresponsiveness, increased levels of eosinophils and NKs and lower numbers of monocytes and CD11b-Ly6C- dendritic cells (DCs). Mice exposed to DEP alone showed increased levels of neutrophils and NKs, reduced numbers of monocytes and alveolar macrophages, and increased levels of CD11b + Ly6C- DCs. The AP sensitized and AP + DEP challenged group also showed asthma-like symptoms such as AHR, as well as increased numbers of eosinophils, neutrophils, CD11b + Ly6C- DCs and decreased levels of total and alveolar macrophages and tolerogenic DCs. Particle deposition was visualised using OPT. In the DEP group the particles were distributed relatively evenly, while in the AP + DEP group they were seen mainly in the large conducting airways. The results show that DEP exposure activates the innate immune response and, together with AP, exacerbates asthma immune hallmarks. This mouse model provides the first evidence of the capacity of DEPs to increase CD11b + Ly6C- (Th2-related) DCs. This study also demonstrates, for the first time, a differential deposition pattern of DEP in lungs depending on asthma status.

XPC-Related Protection Against Carcinogen-Induced Lung Adenocarcinoma is Independent of Lung Inflammation

Background and Hypothesis: Cigarette smoke (CS) exposure causes lung cancer, with both DNA damage and local inflammation playing a critical role in development. Our previous research links the DNA repair protein Xeroderma Pigmentosum Group C (XPC) with protection against lung cancer in CS- and carcinogen-exposed mouse models. In mice (XPC-deficient and wild-type [WT] littermates) exposed to continuous CS for 9 months, neither XPC-deficient nor WT mice develop lung cancer. XPC-deficient but not WT mice exposed to 5 months CS + 4 months air control (AC) (recovery model) develop lung cancer. In a direct carcinogen model, XPC-deficiency accelerates NTCU lung squamous cell development. Our hypothesis is that lung cancers in XPC-deficient mice are independent of treatment alterations in BAL inflammation.&#x0D; Experimental Design or Project Methods: Acellular bronchoalveolar lavage (BAL) samples from the three different mouse CS and carcinogen models were analyzed for the inflammatory cytokines IL-6, IL10, IL-12p70, IL-17A, IFN-γ, MCP-1, and TNF-α by a cytometric bead array (BD Biosciences) using a flow cytometer (FACScan) according to the manufacturer’s instructions. Raw data (mean fluorescence intensity) was analyzed by BD CBA Software. Statistical comparisons were by ANOVA, with p&lt;0.05 considered significant.&#x0D; Results: All measured cytokine levels were low or undetectable in BAL from AC and CS mice, with no significant XPC genotype or treatment-related changes in the measured cytokines. Differences were observed in TNF-α and IL-6 between continuous and recovery CS models independent of treatment or genotype. NTCU caused a significant increase in BAL IL-6 independent of genotype. IL-17a was elevated in NTCU-treated mice that developed lung squamous cell carcinoma.&#x0D; Conclusion and Potential Impact: The XPC genotypic variation seen in lung carcinogenesis appears to be independent of BAL cytokines, suggesting that the variation is due to DNA damage rather than differences in local inflammation. Further mechanistic investigations will focus on DNA damage and repair as drivers of XPC-deficient lung cancers.&#x0D;

Inoculation Pneumonia Caused by Coagulase Negative Staphylococcus.

RationaleAlthough frequently retrieved in tracheal secretions of critically ill patients on mechanical ventilation, the existence of pneumonia caused by coagulase-negative staphylococci (CoNS) remains controversial.ObjectiveTo assess whether Staphylococcus haemolyticus (S. haemolyticus) inoculated in mice’s trachea can infect normal lung parenchyma, increasing concentrations of S. haemolyticus were intratracheally administered in 221 immunocompetent mice.MethodsEach animal received intratracheally phosphate-buffered saline (PBS) (n = 43) or live (n = 141) or inactivated (n = 37) S. haemolyticus at increasing load: 1.0 × 106, 1.0 × 107, and 1.0 × 108 colony forming units (CFU). Forty-three animals were sacrificed at 12 h and 178 were sacrificed at 36 h; 64 served for post-mortem lung histology, 157 served for pre-mortem bronchoalveolar lavage (BAL) analysis, and 42 served for post-mortem quantitative bacteriology of lung tissue. The distribution of biofilm-associated genes was investigated in the S. haemolyticus strain used in our in vivo experiment as well as among 19 other clinical S. haemolyticus strains collected from hospitals or nursing houses.Measurements and Main ResultsIntratracheal inoculation of 1.0 × 108 CFU live S. haemolyticus caused macroscopic and histological confluent pneumonia with significant increase in BAL white cell count, tumor necrosis factor-α (TNF-α), and macrophage inflammatory protein (MIP)-2. At 12 h, high concentrations of S. haemolyticus were identified in BAL. At 36 h, lung injury and BAL inflammation were less severe than at 12 h and moderate concentrations of species belonging to the oropharyngeal flora were identified in lung tissue. The inoculation of 1.0 × 106 and 1.0 × 107 CFU live S. haemolyticus caused histologic interstitial pneumonia and moderate BAL inflammation. Similar results were observed after inoculation of inactivated S. haemolyticus. Moreover, biofilm formation was a common phenotype in S. haemolyticus isolates. The low prevalence of the ica operon in our clinical S. haemolyticus strain collection indicated icaA and icaD independent-biofilm formation.ConclusionIn immunocompetent spontaneously breathing mice, inoculation of S. haemolyticus causes concentration-dependent lung infection that spontaneously recovers over time. icaA and icaD independent biofilm formation is a common phenotype in S. haemolyticus isolates.

Bacterial secretion of histamine within the gut influences immune responses within the lung.

Histamine is an important immunomodulator influencing both the innate and adaptive immune system. Certain host cells express the histidine decarboxylase enzyme (HDC), which is responsible for catalysing the decarboxylation of histidine to histamine. We and others have shown that bacterial strains can also express HDC and secrete histamine; however, the influence of bacterial-derived histamine on the host immune responses distant to the gut is unclear. The Escherichia coli BL21 (Ecoli BL21) strain was genetically modified to express the Morganella morganii (Mmorganii)-derived HDC gene (Ecoli BL21_HTW). Ecoli BL21 and Ecoli BL21_HTW were gavaged to ovalbumin (OVA) sensitized and challenged mice to investigate the effect of bacterial-derived histamine on lung inflammatory responses. Oral administration of Ecoli BL21_HTW, which is able to secrete histamine, to wild-type mice reduced lung eosinophilia and suppressed exvivo OVA-stimulated cytokine secretion from lung cells in the OVA respiratory inflammation mouse model. In histamine receptor 2 (H2R)-deficient mice, administration of histamine-secreting bacteria also reduced inflammatory cell numbers in bronchoalveolar lavage (BAL). However, the suppressive effect of bacterial-derived histamine on BAL inflammation was lost in HDC-deficient mice. This loss of activity was associated with increased expression of histamine degrading enzymes and reduced histamine receptor expression. Histamine secretion from bacteria within the gut can have immunological consequences at distant mucosal sites, such as within the lung. These effects are influenced by host histamine receptor expression and the expression of histamine degrading enzymes.

Dietary wheat amylase trypsin inhibitors exacerbate murine allergic airway inflammation.

Wheat amylase trypsin inhibitors (ATI) are dietary non-gluten proteins that activate the toll-like receptor 4 on myeloid cells, promoting intestinal inflammation. We investigated the effects of dietary ATI on experimental allergic airway inflammation. Mice on a gluten and ATI-free diet (GAFD), sensitized with PBS or ovalbumin (OVA) and challenged with OVA, were compared to mice on a commercial standard chow, a gluten diet naturally containing ~ 0.75% of protein as ATI (G+AD), a gluten diet containing ~ 0.19% of protein as ATI (G-AD) and a GAFD with 1% of protein as ATI (AD). Airway hyperreactivity (AHR), inflammation in bronchoalveolar lavage (BAL) and pulmonary tissue sections were analyzed. Allergic sensitization was assessed ex vivo via proliferation of OVA-stimulated splenocytes. Mice on a GAFD sensitized with PBS did not develop AHR after local provocation with methacholine. Mice on a GAFD or on a G-AD and sensitized with OVA developed milder AHR compared to mice fed a G+AD or an AD. The increased AHR was paralleled by increased BAL eosinophils, IL-5 and IL-13 production, and an enhanced ex vivo splenocyte activation in the ATI-fed groups. Dietary ATI enhance allergic airway inflammation in OVA-challenged mice, while an ATI-free or ATI-reduced diet has a protective effect on AHR. Nutritional wheat ATI, activators of intestinal myeloid cells, may be clinically relevant adjuvants to allergic airway inflammation.

MicroRNA profiling in lung tissue and bronchoalveolar lavage of cigarette smoke-exposed mice and in COPD patients: a translational approach

Chronic obstructive pulmonary disease (COPD) is characterized by a progressive airflow limitation and is associated with a chronic inflammatory response in both airways and lungs. microRNAs (miRNAs) are often highly conserved between species and have an intricate role within homeostatic conditions and immune responses. Also, miRNAs are dysregulated in smoking-associated diseases. We investigated the miRNA profile of 523 miRNAs by stem-loop RT-qPCR in lung tissue and cell-free bronchoalveolar lavage (BAL) supernatant of mice exposed to air or cigarette smoke (CS) for 4 or 24 weeks. After 24 weeks of CS exposure, 31 miRNAs were differentially expressed in lung tissue and 78 in BAL supernatant. Next, we correlated the miRNA profiling data to inflammation in BAL and lung, obtained by flow cytometry or ELISA. In addition, we surveyed for overlap with newly assessed miRNA profiles in bronchial biopsies and with previously assessed miRNA profiles in lung tissue and induced sputum supernatant of smokers with COPD. Several miRNAs showed concordant differential expression between both species including miR-31*, miR-155, miR-218 and let-7c. Thus, investigating miRNA profiling data in different compartments and both species provided accumulating insights in miRNAs that may be relevant in CS-induced inflammation and the pathogenesis of COPD.

Effect of anti-IgE in occupational asthma caused by exposure to low molecular weight agents.

The role of immunoglobulin (Ig)-E in occupational asthma (OA) due to low molecular weight (LMW) agents is not well established compared to classical atopic asthma. In this study, we evaluate whether anti-IgE monoclonal antibody (mAb) has an effect in a mouse model of OA, using persulfate salts. On days 1 and 8, BALB/C mice were dermally sensitized with 5% ammonium persulfate (AP) or dimethyl sulfoxide (DMSO). On days 15, 18, and 21, animals were injected intraperitoneally with anti-IgE mAb or PBS 6 hours before challenge with AP or saline. Airway hyper-responsiveness (AHR) using a methacholine test, airway inflammation in bronchoalveolar lavage (BAL) and lung tissue, and total free IgE in serum samples were analyzed 24, 48, and 96 hours after the last challenge. Anti-IgE mAb treatment almost completely neutralized free serum IgE. In AP-sensitized and challenged mice, anti-IgE mAb treatment abolished AHR 24 hour and 48 hour after the last challenge and significantly reduced the total number of eosinophils and neutrophils 48 hour and 96 hour after the last AP challenge compared with nontreated mice. Levels of interleukin (IL)-13 in BAL were also significantly decreased after anti-IgE administration 24 hour and 48 hour after the last AP challenge. Histological analysis of the lung sections from anti-IgE-treated mice revealed normal inflammatory patterns similar to control groups 48 hour after the last challenge. Anti-IgE-treated mice showed a significant improvement in asthma features related to the AHR and airway inflammation. Anti-IgE mAb has positive effects in OA induced by persulfate salts.

Effects of diesel exhaust particle exposure on a murine model of asthma due to soybean.

BackgroundExposure to soybean allergens has been linked to asthma outbreaks. Exposure to diesel exhaust particles (DEP) has been associated with an increase in the risk of asthma and asthma exacerbation; however, in both cases the underlying mechanisms remain poorly understood, as does the possible interaction between the two entities.ObjectiveTo investigate how the combination of soybean allergens and DEP can affect the induction or exacerbation of asthma in a murine model.MethodsBALB/c mice received intranasal instillations of saline, 3 or 5 mg protein/ml soybean hull extract (SHE), or a combination of one of these three solutions with DEP. Airway hyperresponsiveness (AHR), pulmonary inflammation in bronchoalveolar lavage, total serum immunoglobulin E and histological studies were assessed.ResultsA 5 mg protein/ml SHE solution was able by itself to enhance AHR (p = 0.0033), increase eosinophilic inflammation (p = 0.0003), increase levels of IL-4, IL-5, IL-13, IL-17A, IL-17F and CCL20, and reduce levels of IFN-γ. The combination of 5 mg protein/ml SHE with DEP also produced an increase in AHR and eosinophilic inflammation, but presented a slightly different cytokine profile with higher levels of Th17-related cytokines. However, while the 3 mg protein/ml SHE solution did not induce asthma, co-exposure with DEP resulted in a markedly enhanced AHR (p = 0.002) and eosinophilic inflammation (p = 0.004), with increased levels of IL-5, IL-17F and CCL20 and decreased levels of IFN-γ.Conclusions & clinical relevanceThe combination of soybean allergens and DEP is capable of triggering an asthmatic response through a Th17-related mechanism when the soybean allergen concentration is too low to promote a response by itself. DEP monitoring may be a useful addition to allergen monitoring in order to prevent new asthma outbreaks.

Toluene diisocyanate and methylene diphenyl diisocyanate: asthmatic response and cross-reactivity in a mouse model.

Both 2,4-toluene diisocyanate (TDI) and 4,4-methylene diphenyl diisocyanate (MDI) can cause occupational asthma. In this study, we optimized our mouse model of chemical-induced asthma in the C57Bl/6 mice strain using the model agent TDI. Furthermore, we validated MDI in this mouse model and investigated whether cross-reactivity between TDI and MDI is present. On days 1 and 8, C57Bl/6 mice were dermally treated (20µl/ear) with 3% MDI, 2% TDI or the vehicle acetone olive oil (AOO) (3:2). On day 15, they received a single oropharyngeal challenge with 0.04% MDI, 0.01% TDI or the vehicle AOO (4:1). One day later, airway hyperreactivity (AHR) and pulmonary inflammation in the bronchoalveolar lavage (BAL) were assessed. Furthermore, total serum IgE levels, lymphocyte subpopulations in auricular lymph nodes and cytokine levels in supernatants of lymphocytes were measured. Both dermal sensitization with TDI or MDI resulted in increased total serum IgE levels along with T and B cell proliferation in the auricular lymph nodes. The auricular lymphocytes showed an increased release of both Th2 and Th1 cytokines. Mice sensitized and challenged with either TDI or MDI showed AHR, along with a predominant neutrophil lung inflammation. Mice sensitized with MDI and challenged with TDI or the other way around showed no AHR, nor BAL inflammation. Both TDI and MDI are able to induce an asthma-like response in this mouse model. However, cross-reactivity between both diisocyanates remained absent.

Influenza causes prolonged disruption of the alveolar-capillary barrier in mice unresponsive to mesenchymal stem cell therapy.

Viral pneumonia is a major cause of acute respiratory distress syndrome (ARDS). Anti-inflammatory therapies for viral-induced lung injury show promise in preclinical models. Mesenchymal stem/stromal cells (MSCs) are multipotent, self-renewing cells that secrete anti-inflammatory cytokines and epithelial and endothelial growth factors. We inoculated mice intranasally with influenza A (murine-adapted Puerto Rico/8/34) or PBS, and the mice were killed at multiple time points after infection for measures of lung injury and viral load. We report that influenza induces marked, long-lasting dysfunction of the alveolar-capillary barrier peaking at 1 wk but lasting longer than 3 wk postinfection. Weight loss, commonly employed as a criterion for euthanasia (and hence "survival"), was found to be poorly predictive of the severity of lung injury at its peak; rather, persistent weight loss 11 days postinfection identified mice with impaired injury resolution. Murine and human bone marrow-derived MSCs (obtained from the National Institutes of Health repository) were then administered intravenously during the rapid phase of injury progression. Murine MSCs (mMSCs) given two times 24 h apart failed to improve weight loss, lung water, bronchoalveolar lavage inflammation, or histology. However, mMSCs prevented influenza-induced thrombocytosis and caused a modest reduction in lung viral load at day 7. Human MSCs administered intravenously showed a similar lack of efficacy. The results demonstrate that the influenza murine model bears important similarities to the slow resolution of ARDS in patients. Despite their potent therapeutic effects in many models of acute inflammation and lung injury, MSCs do not improve influenza-mediated lung injury in mice.