Lung Homogenates Research Articles

Acute Exposure to E‐Cigarette Vapor Causes Changes in Apoptotic Pathways in the Lung

BackgroundElectronic cigarette usage is increasing at an alarming rate primarily because of reports implicating their use as safer than traditional cigarettes. However, little is known about the acute effects on lung injury and inflammation. These studies tested the hypothesis that acute exposure to e‐cigarette vapor would result in lung inflammation and injury.MethodsC57Bl/6 mice were exposed to e‐cigarette vapor consisting of 10 mg/mL nicotine in a 50/50 mixture of propylene glycol/vegetable glycerin (PG/VG) or PG/VG alone for 6 hr/day, 5 days/week for either 1 or 2 weeks. Lungs were excised and snap‐frozen for analysis. Lung homogenates were analyzed by western blot for pAKT, pSTAT3, PECAM, BCL‐2, and BAX. RNA was isolated for measurement of MMP9, KC, and VEGF by RT‐PCR.ResultspAKT protein expression was decreased (0.54 vs 1.0 relative density, p=0.02) and pSTAT3 was increased (1.7 vs 1.0 relative density, p=0.02) in the e‐cigarette exposed mice vs PG/VG exposed mice after 1 week of exposure. At 2 weeks, pSTAT3 remained increased (1.9 vs 1.0 relative density, p=0.01) and both BCL‐2 (2.5 vs 1.0 relative density, p=0.02) and BAX (1.7 vs 1.0 relative density, p<0.05) were increased in the exposed mice compared to mice exposed to PG/VG alone. No differences were observed in PECAM, MMP9, KC, or VEGF.ConclusionsAcute exposure to e‐cigarette vapor caused changes in signaling molecules associated with apoptosis. While we did not observe differences in the inflammatory pathways tested, additional inflammatory and apoptotic markers may yield insights into the acute effects of e‐cigarette vapor exposure on the lung.Support or Funding InformationNIH NHLBI R01 HL139348 02This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Female and male mouse lung group 2 innate lymphoid cells differ in gene expression profiles and cytokine production.

Epidemiological studies have shown sex differences in prevalence of non-allergic asthma. Recent reports demonstrated negative effects of androgen signaling on group 2 innate lymphoid cells (ILC2s), explaining a potential mechanism behind sex bias in asthma prevalence. To further understand sex-related differences in ILC2 functions and ILC2 intrinsic or lung environmental mechanisms behind it, we have investigated the effects of sex and age on lung ILC2 function, the amounts of ILC2-activating cytokines in the lung and gene expression profiles of male and female ILC2s. Flow cytometric analyses of naive male and female mouse lung ILC2s showed no difference in their numbers. However, upon three daily intranasal IL-33 injections, lung ILC2s in postpubertal female mice expanded to a greater degree than male counterpart. In line with in vivo results, purified female mouse lung ILC2s produced more cytokines than male ILC2s upon in vitro stimulation. Gene expression profiles of purified naïve male and female ILC2s differed in 4% of the genes, and gene set enrichment analysis showed that female ILC2s are enriched for gene signatures of memory T cells. We did not observe similar degree of differences between female and male ILC2s after IL-33 stimulation. ILC2-activating cytokines including IL-33, IL-7 and TSLP were more highly expressed in whole lung homogenate samples prepared from naïve post pubertal female mouse lung than male mouse lung. Moreover, the differences in responsiveness of male and female ILC2s to IL-33 were not affected in IL-33-deficient mice. These results suggest that female ILC2s are more readily activated than male ILC2s due to their gene expression at the naïve state, which is potentially influenced by the lung environment.

Simultaneous Administration of Recombinant Measles Viruses Expressing Respiratory Syncytial Virus Fusion (F) and Nucleo (N) Proteins Induced Humoral and Cellular Immune Responses in Cotton Rats.

We previously reported that recombinant measles virus expressing the respiratory syncytial virus (RSV) fusion protein (F), MVAIK/RSV/F, induced neutralizing antibodies against RSV, and those expressing RSV-NP (MVAIK/RSV/NP) and M2-1 (MVAIK/RSV/M2-1) induced RSV-specific CD8+/IFN-γ+ cells, but not neutralizing antibodies. In the present study, MVAIK/RSV/F and MVAIK/RSV/NP were simultaneously administered to cotton rats and immune responses and protective effects were compared with MVAIK/RSV/F alone. Sufficient neutralizing antibodies against RSV and RSV-specific CD8+/IFN-γ+ cells were observed after re-immunization with simultaneous administration. After the RSV challenge, CD8+/IFN-γ+ increased in spleen cells obtained from the simultaneous immunization group in response to F and NP peptides. Higher numbers of CD8+/IFN-γ+ and CD4+/IFN-γ+ cells were detected in lung tissues from the simultaneous immunization group after the RSV challenge. No detectable RSV was recovered from lung homogenates in the immunized groups. Mild inflammatory reactions with the thickening of broncho-epithelial cells and the infiltration of inflammatory cells were observed in lung tissues obtained from cotton rats immunized with MVAIK/RSV/F alone after the RSV challenge. No inflammatory responses were observed after the RSV challenge in the simultaneous immunization groups. The present results indicate that combined administration with MVAIK/RSV/F and MVAIK/RSV/NP induces humoral and cellular immune responses and shows effective protection against RSV, suggesting the importance of cellular immunity.

Evidence of Influenza A in Wild Norway Rats (Rattus norvegicus) in Boston, Massachusetts.

Influenza A virus (IAV) is known to circulate among human and animal reservoirs, yet there are few studies that address the potential for urban rodents to carry and shed IAV. Rodents are often used as influenza models in the lab, but the few field studies that have looked for evidence of IAV in rodents have done so primarily in rural areas following outbreaks of IAV in poultry. This study sought to assess the prevalence of IAV recovered from wild Norway rats in a dense urban location (Boston). To do this, we sampled the oronasal cavity, paws, and lungs of Norway rats trapped by the City of Boston’s Inspectional Services from December 2016 to September 2018. All samples were screened by real-time, reverse transcriptase PCR targeting the conserved IAV matrix segment. A total of 163 rats were trapped, 18 of which (11.04%) were RT-PCR positive for IAV in either oronasal swabs (9), paw swabs (9), both (2), or lung homogenates (2). A generalized linear model indicated that month and geographic location were correlated with IAV-positive PCR status of rats. A seasonal trend in IAV-PCR status was observed with the highest prevalence occurring in the winter months (December-January) followed by a decline over the course of the year, reaching its lowest prevalence in September. Sex and weight of rats were not significantly associated with IAV-PCR status, suggesting that rodent demography is not a primary driver of infection. This pilot study provides evidence of the need to further investigate the role that wild rats may play as reservoirs or mechanical vectors for IAV circulation in urban environments across seasons.

Investigation of the relation between feline infectious peritonitis and retroviruses in cats

Feline infectious peritonitis (FIP) infection is a highly pathogenic and fatal systemic inflammatory disease in cats. Although FIP infection is associated with the immune system, there are several predisposing factors of the disease. FIP has a high rate of interaction with other infectious agents. The feline immunodeficiency virus (FIV) and Feline Leukemia Virus (FeLV) infections play a predisposing role by reducing immunity against FIP. This study was conducted with the Turkish Van cats, which is a cat breed specific to the Lake Van region of Turkey, between 2014 and 2015. Ascites and organ damage symptoms were identified by pathological analysis in 15 Van cats that were brought to the Van Yüzüncü Yıl University. Polymerase chain reaction (PCR) was used to investigate the presence of FIV and FeLV in the homogenate of brain, lung, liver, kidney, spleen and intestines tissue samples with lesions. As a result of the analysis, FIV was identified in 1 (6.7%) out of 15 cats, and all cat samples were found to be positive in terms of FeLV (100%). In the phylogenetic analysis of positive samples, all FeLVs were observed to be in endogenous-FeLVs. In the FIV phylogenetic analysis, our study strain was found to be in the FIV sub-group B. The fact that FIP positive cats were also FeLV positive at the same time has attracted the attention to the pathogenesis of Endogenous-FeLV in malignant diseases, which has not yet been understood. Particularly, it was concluded that the prevalence of FIP infection can be reduced by paying attention to FIV and FeLV vaccination in multiple-cat sheltering environments in young cats.

Selective Inactivation of Intracellular BiP/GRP78 Attenuates Endothelial Inflammation and Permeability in Acute Lung Injury

The role of Endoplasmic Reticulum Chaperone and Signaling Regulator BiP/GRP78 in acute inflammatory injury, particularly in the context of lung endothelium, is poorly defined. In his study, we monitored the effect of SubAB, a holoenzyme that cleaves and specifically inactivates BiP/GRP78 and its inactive mutant SubAA272B on lung inflammatory injury in an aerosolized LPS inhalation mouse model of acute lung injury (ALI). Analysis of lung homogenates and bronchoalveolar lavage (BAL) fluid showed that LPS-induced lung inflammation and injury were significantly inhibited in SubAB- but not in SubAA272B-treated mice. SubAB-treated mice were also protected from LPS-induced decrease in lung compliance. Gene transfer of dominant negative mutant of BiP in the lung endothelium protected against LPS-induced lung inflammatory responses. Consistent with this, stimulation of endothelial cells (EC) with thrombin caused an increase in BiP/GRP78 levels and inhibition of ER stress with 4-phenylbutyric acid (4-PBA) prevented this response as well as increase in VCAM-1, ICAM-1, IL-6, and IL-8 levels. Importantly, thrombin-induced Ca2+ signaling and EC permeability were also prevented upon BiP/GRP78 inactivation. The above EC responses are mediated by intracellular BiP/GRP78 and not by cell surface BiP/GRP78. Together, these data identify intracellular BiP/GRP78 as a novel regulator of endothelial dysfunction associated with ALI.

Exacerbating effects of trimellitic anhydride in ovalbumin-induced asthmatic mice and the gene and protein expressions of TRPA1, TRPV1, TRPV2 in lung tissue

With the increasing morbidity and mortality of asthma, asthma aggravated by environmental pollution has drawn more attention. This study investigated the exacerbating effects of trimellitic anhydride (TMA), a typical pollutant, in ovalbumin (OVA)-induced asthmatic mice and the gene and protein expressions of TRPA1, V1, V2 in lung tissue. Female BALB/c mice were respectively administered for 42 days as follow: sensitized and challenged with OVA, sensitized and challenged with TMA, sensitized with OVA and challenged with OVA plus TMA, as well as sensitized and challenged with OVA plus TMA. 24 h after the last challenge, the changes in airway resistance (RI) and lung dynamic compliance (Cdyn) were tested. The levels of the inflammatory cells in blood and bronchoalveolar lavage fluid (BALF) were determined. The gene and protein expressions of TRPA1, V1, V2 in lung tissue were examined, and levels of interleukin (IL)-4, −13, substance P (SP), prostaglandin D2 (PGD2), nerve growth factor (NGF) in BALF and the supernatant of lung homogenate were measured. The results indicated that OVA plus TMA significantly increased the amount of inflammatory cells in blood and BALF, enhanced RI while decreased Cdyn, and aggravated lung injury. Increased gene and protein expressions of TRPA1, V1, V2 in lung tissue, level of IL-4 in the supernatant of lung homogenate, levels of IL-13, SP, PGD2, NGF in BALF and the supernatant of lung homogenate were observed. It was suggested that exacerbating effects of TMA in OVA-induced asthma might be related to the regulation of TRPA1, V1, V2 and relevant neurokines.

CFTR dysfunction increases endoglin and TGF-β signaling in airway epithelia.

Endoglin (ENG) regulates signaling by transforming growth factor‐β (TGF‐β), a genetic modifier of cystic fibrosis (CF) lung disease severity. We hypothesized that ENG mediates TGF‐β pathobiology in CF airway epithelia. Comparing CF and non‐CF human lungs, we measured ENG by qPCR, immunoblotting and ELISA. In human bronchial epithelial cell lines (16HBE), we used CFTR siRNA knockdown and functional inhibition (CFTRINH‐172) to connect loss of CFTR to ENG synthesis. Plasmid overexpression of ENG assessed the direct effect of ENG on TGF‐β transcription and signal amplification in 16HBE cells. We found ENG protein to be increased more than fivefold both in human CF bronchoalveolar fluid (BALF) and human CF lung homogenates. ENG transcripts were increased threefold in CF, with a twofold increase in TGF‐β signaling. CFTR knockdown in 16HBE cells tripled ENG transcription and doubled protein levels with corresponding increases in TGF‐β signaling. Plasmid overexpression of ENG alone nearly doubled TGF‐β1 mRNA and increased TGF‐β signaling in 16HBE cells. These experiments identify that loss of CFTR function increases ENG expression in CF epithelia and amplifies TGF‐β signaling. Targeting ENG may offer a novel therapeutic opportunity to address TGF‐β associated pathobiology in CF.

Hypergravity stimuli alleviate the Th2 allergic reaction: potential as an adjuvant anti-allergic therapy

Recent studies suggest that changes in gravity can cause immunological effects. We investigated the changes of Th2 allergic inflammation in murine model of allergic asthma, after exposure to hypergravity. Group A (control group) was intraperitoneally and intranasally injected with physiological saline. Group B (allergic group) received intraperitoneal and nasal ovalbumin for the induction of allergic asthma. Mice in group C (normogravity control) were exposed to mild rotational stimulation (for rotational stimulus stress, but gravity itself 1G) while inducing allergy through ovalbumin administration. Finally, group D (hypergravity group) was exposed to 5 G of hypergravity through rotation throughout the period of allergic induction (4 weeks). To determine the effects of hypergravity on Th2 allergic inflammation, we measured total and OVA-specific IgE in serum. We also measured the number of inflammatory cells (eosinophils, neutrophils, lymphocytes and macrophages) in the broncho-alveolar lavage (BAL). We performed real-time PCR to detect the genetic expression of IL-4, IL-5, and IL-13 using lung homogenate tissue. We could find a significant decrease in serum total IgE in Group D compared to Groups B and C (p<0.05). Group D also showed significant decrease in eosinophil count in BAL fluid. Real-time PCR revealed that Th2 cytokine gene expression (IL-4, IL-5, IL-13) was significantly inhibited in Group D, compared to Groups B and C (p<0.05). Moderate, proper hypergravity could have beneficial effect in individuals with allergy.

Rezafungin Prophylactic Efficacy in a Mouse Model of Pneumocystis Pneumonia

Background The risk of Pneumocystis pneumonia often warrants antifungal prophylaxis for bone marrow and solid organ transplantation patients. However, complications such as myelosuppression, nephrotoxicity, and intolerance with the existing standard, TMP/SMX, may hinder or interrupt prophylaxis. Rezafungin (RZF) is a novel echinocandin in development for prevention of invasive fungal infections caused by Candida, Aspergillus, and Pneumocystis species in patients at high risk of infection. RZF has a favorable safety and tolerability profile and a low risk of drug-drug interactions. Furthermore, the stability and pharmacokinetics of RZF allow for once-weekly dosing and broad distribution to the lung and other target organs. RZF was shown to prevent in vitro Pneumocystis biofilm formation and to reduce the viability of mature biofilms. A previous prophylactic study was conducted using a broader range of RZF doses. In the current study, the efficacy of RZF was evaluated to better understand the minimum doses necessary to prevent Pneumocystis growth in a mouse model. Methods C3H/HeN mice were immunosuppressed (dexamethasone 4 mg/L in acidified drinking water) and then infected intranasally with P. murina (2 × 106/50 µL). Given the slow growth of P. murina, test agents were administered at the same time mice were inoculated to test for prophylactic efficacy. Mice received intraperitoneal injections of either vehicle (control/steroid [C/S]), TMP/SMX 50/250 mg/kg/3x/week (wk), caspofungin 5 mg/kg once daily, or RZF 5 mg/kg or 0.5 mg/kg once daily, 1x, or 2x/wk. After a 6-week dosing period, mice were sacrificed and lung homogenates were processed for analysis to quantify the nuclei (trophic) and asci (cyst) forms of Pneumocystis. Prophylaxis efficacy was based on reduction of organism burden compared with C/S. Nuclei and asci counts were log transformed and analyzed by ANOVA; individual groups were compared by the Student-Newman-Keuls t test. Survival rates were compared using GraphPad Prism v5. Results All mice in the RZF groups had significantly reduced nuclei and asci burdens compared with the C/S group, and all but the lowest doses of RZF (0.5 mg/kg 1x or 2x/wk) worked as well as TMP/SMX at reducing nuclei levels (Fig 1). Similarly, all RZF groups except for the 0.5 mg/kg 1x/wk group showed reductions in asci levels comparable to that of TMP/SMX (Fig 1). The survival rates were not statistically different between treatment groups. Conclusions RZF demonstrated potent in vivo efficacy as prophylaxis against Pneumocystis in an in vivo mouse infection model at dose regimens much lower than the human equivalent Ph3 regimen. These data support the development of RZF for the prevention of invasive fungal infections including Pneumocystis pneumonia.

Thioredoxin Reductase-1 Inhibition Augments Endogenous Glutathione-Dependent Antioxidant Responses in Experimental Bronchopulmonary Dysplasia.

Background Aurothioglucose- (ATG-) mediated inhibition of thioredoxin reductase-1 (TXNRD1) improves alveolarization in experimental murine bronchopulmonary dysplasia (BPD). Glutathione (GSH) mediates susceptibility to neonatal and adult oxidative lung injury. We have previously shown that ATG attenuates hyperoxic lung injury and enhances glutathione- (GSH-) dependent antioxidant defenses in adult mice. Hypothesis The present studies evaluated the effects of TXNRD1 inhibition on GSH-dependent antioxidant defenses in newborn mice in vivo and lung epithelia in vitro. Methods Newborn mice received intraperitoneal ATG or saline prior to room air or 85% hyperoxia exposure. Glutamate-cysteine ligase (GCL) catalytic (Gclc) and modifier (Gclm) mRNA levels, total GSH levels, total GSH peroxidase (GPx) activity, and Gpx2 expression were determined in lung homogenates. In vitro, murine transformed club cells (mtCCs) were treated with the TXNRD1 inhibitor auranofin (AFN) or vehicle in the presence or absence of the GCL inhibitor buthionine sulfoximine (BSO). Results In vivo, ATG enhanced hyperoxia-induced increases in Gclc mRNA levels, total GSH contents, and GPx activity. In vitro, AFN increased Gclm mRNA levels, intracellular and extracellular GSH levels, and GPx activity. BSO prevented AFN-induced increases in GSH levels. Conclusions Our data are consistent with a model in which TXNRD1 inhibition augments hyperoxia-induced GSH-dependent antioxidant responses in neonatal mice. Discrepancies between in vivo and in vitro results highlight the need for methodologies that permit accurate assessments of the GSH system at the single-cell level.

Pulmonary vascular disease is evident in gene regulation of experimental bronchopulmonary dysplasia

Objective: To examine the gene expression regarding pulmonary vascular disease in experimental bronchopulmonary dysplasia in young mice. Premature delivery puts babies at risk of severe complications. Bronchopulmonary dysplasia (BPD) is a common complication of premature birth leading to lifelong affection of pulmonary function. BPD is recognized as a disease of arrested alveolar development. The disease process is not fully described and no complete cure or prevention is known. The focus of interest in the search for treatment and prevention of BPD has traditionally been at airspace level; however, the pulmonary vasculature is increasingly acknowledged in the pathology of BPD. The aim of the investigation was to study the gene expression in lungs with BPD with regards to pulmonary vascular disease (PVD).Methods: We employed a murine model of hyperoxia-induced BPD and gene expression microarray technique to determine the mRNA expression in lung tissue from young mice. We combined gene expression pathway analysis and analyzed the biological function of multiple single gene transcripts from lung homogenate to study the PVD relevant gene expression.Results: There were n = 117 significantly differentially regulated genes related to PVD through down-regulation of contractile elements, up- and down-regulation of factors involved in vascular tone and tissue-specific genes. Several genes also allowed for pinpointing gene expression differences to the pulmonary vasculature. The gene Nppa coding for a natriuretic peptide, a potent vasodilator, was significantly down-regulated and there was a significant up-regulation of Pde1a (phosphodiesterase 1A), Ptger3 (prostaglandin e receptor 3), and Ptgs1 (prostaglandin-endoperoxide synthase one).Conclusion: The pulmonary vasculature is affected by the arrest of secondary alveolarization as seen by differentially regulated genes involved in vascular tone and pulmonary vasculature suggesting BPD is not purely an airspace disease. Clues to prevention and treatment may lie in the pulmonary vascular system.

Chemokine (C-X-C motif) receptor 4 regulates lung endothelial barrier permeability during resuscitation from hemorrhagic shock

Chemokine (C-X-C motif) receptor 4 (CXCR4) agonists have been shown to protect lung endothelial barrier function in vitro. In vivo effects of CXCR4 modulation on lung endothelial permeability are unknown. Here we tested the effects of the CXCR4 agonist ubiquitin and the antagonist AMD3100 on lung vascular permeability and cytokine concentrations in a rat hemorrhage model. Animals were hemorrhaged (mean arterial blood pressure 30 mmHg for 30 min), treated with vehicle, ubiquitin (0.7 and 3.5 µmol/kg) or AMD3100 (3.5 µmol/kg), and resuscitated with crystalloids. Evans blue extravasation was employed to quantify lung vascular permeability. Ubiquitin dose-dependently reduced Evans blue extravasation into the lung. AMD3100 increased Evans blue extravasation. With AMD3100, TNFalpha levels in lung homogenates were increased; while TNFalpha levels were lower with ubiquitin, these differences did not reach statistical significance. Our findings suggest that CXCR4 regulates lung vascular permeability and further point towards CXCR4 as a drug target to confer lung protection during resuscitation from traumatic-hemorrhagic shock.

The TLR4 Agonist Immunomax Affects the Phenotype of Mouse Lung Macrophages during Respiratory Syncytial Virus Infection

In the study, the effect of the TLR4 agonist Immunomax was investigated in vitro and in vivo. In particular, Immunomax was shown to polarize mouse bone marrow macrophages from the M0 and M2 states into the M1 state (ARG1 and iNOS mRNA expression levels were used to identify the mouse M1 and M2 phenotypes). Next, we investigated the prophylactic antiviral effect of Immunomax in both a model of mouse respiratory syncytial virus (RSV) infection and a model of RSV-induced bronchial asthma (BA) exacerbation. In the experiment with RSV-induced BA exacerbation, Immunomax-treated mice were characterized by a significant decrease of the viral load in lung homogenates, an increased amount of M1 macrophages in the lung, a tendency toward Th2-dependent ovalbumin-specific IgG1 antibodies decrease in blood serum, a significant increase in RSV-activated CD4+ T cells secreting IFNγ (Th1 cells), and a simultaneous significant decrease in the amount of CD4+ cells secreting IL-4 (Th2 cells) in the mouse spleen, which were detected by ELISPOT 1.5 months after experiment. These findings suggest that treatment with the TLR4 agonist Immunomax polarizes the immune response towards antiviral Th1 and may be used for short-term antiviral prophylaxis to prevent acute respiratory viral infections in asthmatics.

Antiasthmatic potential of Zizyphus jujuba Mill and Jujuboside B. – Possible role in the treatment of asthma

Zizyphus jujuba Mill, a famous oriental traditional medicine, has been reported to exhibit diverse activities in biological systems including the respiratory system. However, a little information is available on its antiasthmatic activity. Jujuboside B (JB) is a natural saponin and one of the active constituent of fruits of Zizyphus jujuba. In the present investigation, JB was isolated from ethanolic extracts of fruits of Zizyphus jujuba (EZJF). EZJF and JB were then evaluated for anti-asthmatic activity using various screening methods. JB was additionally evaluated using ovalbumin (OVA) -induced allergic asthma in mice. Results obtained in the present study showed that EZJF and JB significantly inhibited clonidine-induced catalepsy, milk-induced leucocytosis and eosinophilia, clonidine-induced mast cell degranulation, and passive paw anaphylaxis. The number of inflammatory cells in bronchoalveolar lavage (BAL) fluid was considerably lowered and the severity of pulmonary inflammation was alleviated in the mice pretreated with JB. The high-level expression of T-helper type 2 (TH2) cytokines was markedly reduced in the serum, BAL fluid, and lung homogenates. Thus EZJF and JB showed potent anti-asthmatic activity. Hence EZJF and JB possess a potential role in the treatment of asthma.

CD11b Regulates Fungal Outgrowth but Not Neutrophil Recruitment in a Mouse Model of Invasive Pulmonary Aspergillosis

Background and Aims: In immunosuppressed individuals Aspergillus (A.) fumigatus is a frequent cause of invasive pulmonary aspergillosis (IPA) which is highly associated with relevant morbidity and mortality. Moreover, it often occurs in patients suffering from leukocyte-adhesion deficiency type 1 (LAD1) which is triggered by a functional loss of CD18 in ß2 integrin receptors as these receptors consist of an alpha subunit (CD11a-CD11d) and CD18 as the common beta subunit. ß2 integrin receptors are differentially expressed by leukocytes, and are required for cell-cell interaction, transendothelial migration, uptake of opsonized pathogens, and cell signaling processes. Here, we asked for the importance of CD11b/CD18 also termed MAC-1 which is required for phagocytosis of opsonized A. fumigatus conidia by polymorphonuclear neutrophils (PMN) for control of pulmonary A. fumigatus infection.Methods: We used a murine IPA model (C57BL/6) and challenged CD11b deficient (CD11b-/-) or wild type (WT) mice with A. fumigatus conidia intratracheally. Afterwards, some mice were sacrificed 24h after infection. In these mice PMN recruitment and cytokine patterns were examined by analyzing bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) using flow cytometry, cytospin analysis, and cytometric bead array. Additionally, pulmonary fungal clearance and inflammation in murine lungs were analyzed by fungal culture assays and histopathologic examination using a scoring system. Furthermore, survival was studied with neutropenic animals serving as positive controls. To determine PMNs phagocytic activity and fungal killing capacity ex vivo, PMN were purified from bone marrow of CD11b-/- or WT mice by magnetic cell sorting using Ly6G specific antibodies. Afterwards, isolated PMN were stimulated with pacific blue-labeled tomato red-fluorescent modified A. fumigatus conidia and analyzed by flow cytometry.Results: We found that lung homogenates from CD11b-/- mice obtained 24h after infection showed an enhanced fungal burden as compared to lungs from WT mice. In contrast, lung tissue from infected CD11b-/- mice displayed impaired pulmonary inflammation as assessed by Hematoxilin-Eosin (HE) staining. Furthermore, the number of mucus-producing cells in bronchi of A. fumigatus infected CD11b-/- mice was decreased compared to cells in bronchi of WT mice. However, we observed markedly higher numbers of PMN in BALF of infected CD11b-/- mice compared to corresponding WT mice samples. In contrast, BALF derived from infected CD11b-/- mice contained lower levels of three different proinflammatory cytokines (TNF-α, IL-1α, IL-1β) compared to BALF from WT mice while levels of other cytokines and chemokines (IL-5, IL-6, IL-10, GM-CSF, CXCL1, CCL2) were comparable. In contrast, we measured higher levels of the chemokine CCL5 known as a relevant chemoattractant in innate and adaptive immune cells in BALF obtained from CD11b-/- mice. Interestingly, numbers of PMN, lymphocytes, and monocytes in the peripheral blood of A. fumigatus infected mice did not differ in a genotype-dependent manner. However, CD11b-/- mice PMN showed lower phagocytic activity than WT PMN, indicating an impaired capability to clear A. fumigatus. Nevertheless, CD11b-/- mice were finally characterized by similar long-term survival as WT mice after IPA induction while the PMN-depleted control mice died as expected.Conclusions: Our study demonstrates, that CD11b deficiency on myeloid cells affects the early course of IPA. This may be due to the importance of MAC-1 for PMN effector functions, and their interplay with DC and other leukocytes. Further work is necessary to elucidate the long-term course of IPA in CD11b-/- mice with regard to the interplay of PMN with dendritic cells, the efficacy of adaptive immune responses, and the potential pulmonary overexpression of CCL5. Beyond patients with LAD1 syndrome, we suggest our findings as being clinically relevant in other immunocompromised patients suffering from severe opportunistic infections. DisclosuresRadsak:Celgene: Honoraria, Other: Travel grant; Jazz Pharmaceuticals: Other: Travel grant; TEVA: Consultancy; Gilead: Other: Travel grant; Takeda: Consultancy; Novartis: Consultancy, Honoraria; Daiichi Sankyo: Honoraria, Other: Travel grant.

Cannabidiol reduces airway inflammation and fibrosis in experimental allergic asthma

Asthma is characterized by chronic lung inflammation and airway hyperresponsiveness. Asthma remains a major public health problem and, at present, there are no effective interventions capable of reversing airway remodelling. Cannabidiol (CBD) is known to exert immunomodulatory effects through the activation of cannabinoid-1 and − 2 (CB1 and CB2) receptors located in the central nervous system and immune cells, respectively. However, as the role of CBD on airway remodelling and the mechanisms of CB1 and CB2 aren’t fully elucidated, this study was designed to evaluate the effects of cannabidiol in this scenario. Allergic asthma was induced in Balb/c mice exposed to ovalbumin, and respiratory mechanics, collagen fibre content in airway and alveolar septa, cytokine levels, and CB1 and CB2 expression were determined. Moreover, expressions of CB1 and CB2 in induced sputum of asthmatic individuals and their correlation with airway inflammation and lung function were also evaluated. CBD treatment, regardless of dosage, decreased airway hyperresponsiveness, whereas static lung elastance only reduced with high dose. These outcomes were accompanied by decreases in collagen fibre content in both airway and alveolar septa and the expression of markers associated with inflammation in the bronchoalveolar lavage fluid and lung homogenate. There was a significant and inverse correlation between CB1 levels and lung function in asthmatic patients. CBD treatment decreased the inflammatory and remodelling processes in the model of allergic asthma. The mechanisms of action appear to be mediated by CB1/CB2 signalling, but these receptors may act differently on lung inflammation and remodelling.

ДОСЛІДЖЕННЯ ЕНЗИМНОЇ ЛАНКИ АНТИОКСИДАНТНОЇ СИСТЕМИ В ЩУРІВ ЗА УМОВИ ДІЇ ТЮТЮНОВОГО ДИМУ НА ТЛІ ЗАСТОСУВАННЯ НАТРІЙ ГЛУТАМАТУ В СТАТЕВОМУ І ВІКОВОМУ АСПЕКТАХ

Вступ. Значна розповсюдженість тютюнокуріння – глобальна проблема людства, на вирішення якої спрямовані зусилля багатьох учених і фахівців. Водночас відмітною особливістю сучасних харчових технологій є використання харчових добавок. До найпоширеніших харчових добавок як в Україні, так і в Європі належить натрій глутамат (Е621), який не завжди безпечний для здоров’я людини.&#x0D; Мета дослідження – вивчити стан ензимної ланки антиоксидантної системи в щурів за умови дії тютюнового диму на тлі застосування натрій глутамату в статевому і віковому аспектах.&#x0D; Методи дослідження. Досліди проведено на 96 білих нелінійних статевозрілих і статевонезрілих щурах обох статей. Кожну групу тварин було поділено на 4 підгрупи: 1-ша – контроль; 2-га – щури, яким моделювали “пасивне тютюнокуріння”; 3-тя – щури, яким вводили натрій глутамат; 4-та – щури, яким моделювали “пасивне тютюнокуріння” на тлі введення натрій глутамату.&#x0D; Результати й обговорення. Надмірне утворення продуктів вільнорадикального окиснення за умови ізольованої дії тютюнового диму викликало виснаження антиоксидантного потенціалу крові та тканин легень, що проявлялося достовірним зменшенням супероксиддисмутазної активності в гемолізатах еритроцитів на 28,8 % відносно контрольної групи, а в супернатанті гомогенату легень – на 53,1 % (р&lt;0,001) відповідно. “Пасивне тютюнокуріння” на тлі застосування натрій глутамату супроводжувалося більшим її зниженням (на 41,0 %, р&lt;0,001) відносно контрольної групи, що на 17,1 % (р&lt;0,02) менше від даного показника при ізольованій дії тютюнового диму в гемолізатах еритроцитів та на 58,7 % – у супернатанті гомогенату легень, що на 12,0 % (р&lt;0,02) нижче від цього показника за умови ізольованої дії тютюнового диму. Однонаправлені зміни спостерігали і щодо каталазної активності.&#x0D; Висновки. За умови дії тютюнового диму спостерігають виснаження антиоксидантного потенціалу (зниження супероксиддисмутазної і каталазної активності) крові та тканин легень, більш виражене при “пасивному тютюнокурінні” на тлі застосування натрій глутамату. В статевому аспекті показники антиоксидантного захисту за умови “пасивного тютюнокуріння” на тлі застосування натрій глутамату більш виражено знижуються в самок, а при віковому зіставленні змін активності даних ензимів встановлено їх інтенсивніше зменшення у статевонезрілих щурів.

Impact of one versus two doses of mesenchymal stromal cells on lung and cardiovascular repair in experimental emphysema

BackgroundA single administration of mesenchymal stromal cells (MSCs) has been shown to reduce lung inflammation in experimental elastase-induced emphysema; however, effects were limited in terms of lung-tissue repair and cardiac function improvement. We hypothesized that two doses of MSCs could induce further lung and cardiovascular repair by mitigating inflammation and remodeling in a model of emphysema induced by multiple elastase instillations. We aimed to comparatively investigate the effects of one versus two doses of MSCs, administered 1 week apart, in a murine model of elastase-induced emphysema.MethodsC57BL/6 mice were randomly divided into control (CTRL) and emphysema (E) groups. Mice in the E group received porcine pancreatic elastase (0.2 IU, 50 μL) intratracheally once weekly for four consecutive weeks; the CTRL animals received sterile saline (50 μL) using the same protocol. Three hours after the last instillation, the E group was further randomized to receive either saline (SAL) or murine MSCs (105 cells) intratracheally, in one or two doses (1 week apart). Fourteen days later, mice were euthanized, and all data analyzed.ResultsBoth one and two doses of MSCs improved lung mechanics, reducing keratinocyte-derived chemokine and transforming growth factor-β levels in lung homogenates, total cell and macrophage counts in bronchoalveolar lavage fluid (BALF), and collagen fiber content in airways and blood vessels, as well as increasing vascular endothelial growth factor in lung homogenates and elastic fiber content in lung parenchyma. However, only the two-dose group exhibited reductions in tumor necrosis factor-α in lung tissue, BALF neutrophil and lymphocyte count, thymus weight, and total cellularity, as well as CD8+ cell counts and cervical lymph node CD4+ and CD8+ T cell counts, as well as further increased elastic fiber content in the lung parenchyma and reduced severity of pulmonary arterial hypertension.ConclusionsTwo doses of MSCs enhanced lung repair and improvement in cardiac function, while inducing T cell immunosuppression, mainly of CD8+ cells, in elastase-induced emphysema.

IL-1R and Inflammasomes Mediate Early Pulmonary Protective Mechanisms in Respiratory Brucella Abortus Infection.

Brucella spp. infection is frequently acquired through contaminated aerosols. The role of interleukin-1 beta (IL-1β) in the early pulmonary response to respiratory Brucella infection is unknown. As shown here, IL-1β levels in lung homogenates and bronchoalveolar lavage fluid (BALF) of mice intratracheally inoculated with B. abortus were increased at 3 and 7 days p.i. At 7 days p.i., pulmonary CFU numbers were higher in IL-1 receptor (IL-1R) knockout (KO) mice than in wild type (WT) mice. At different times p.i. CFU in lungs and BALF were higher in mice lacking some inflammasome components (caspase-1, AIM2, NLRP3) than in WT mice. At 2 days p.i. pulmonary levels of IL-1β and CXCL1 (neutrophils chemoattractant) were lower in caspase-1/11 KO mice. At day 3 p.i., neutrophils counts in BALF were lower in caspase-1/11 KO mice than in WT mice. During in vitro infections, IL-1β secretion was lower in alveolar macrophages from caspase-1/11, NLRP3 or AIM2 KO mice than in WT controls. Similarly, IL-1β production by B. abortus-infected alveolar epithelial cells was reduced by pretreatment with a specific caspase-1 inhibitor. This study shows that IL-1R, probably through IL-1β action, and the NLRP3 and AIM2 inflammasomes are involved in pulmonary innate immune protective mechanisms against respiratory B. abortus infection.