48 research outputs found
Interaction of allergic airway inflammation and innate immunity: hygiene and beyond
The lung is constantly exposed to the environment and its microbial components. Infections of the respiratory tract are amongst the most common diseases. Several concepts describe how this microbial exposure interacts with allergic airway disease as it is found in patients with asthma. Infections are classical triggers of asthma exacerbations. In contrast, the hygiene hypothesis offers an explanation for the increase in allergic diseases by establishing a connection between microbial exposure during childhood and the risk of developing asthma. This premise states that the microbial environment interacts with the innate immune system and that this interrelation is needed for the fine-tuning of the overall immune response. Based on the observed protective effect of farming environments against asthma, animal models have been developed to determine the effect of specific bacterial stimuli on the development of allergic inflammation. A variety of studies have shown a protective effect of bacterial products in allergen-induced lung inflammation. Conversely, recent studies have also shown that allergic inflammation inhibits antimicrobial host defense and renders animals more susceptible to bacterial infections. This paper focuses on examples of animal models of allergic disease that deal with the complex interactions of the innate and adaptive immune system and microbial stressors
IL-17 Cytokines and Chronic Lung Diseases
IL-17 cytokines are expressed by numerous cells (e.g., gamma delta (γδ) T, innate lymphoid
(ILC), Th17, epithelial cells). They contribute to the elimination of bacteria through the induction
of cytokines and chemokines which mediate the recruitment of inflammatory cells to the site of
infection. However, IL-17-driven inflammation also likely promotes the progression of chronic lung
diseases, such as chronic obstructive pulmonary disease (COPD), lung cancer, cystic fibrosis, and
asthma. In this review, we highlight the role of IL-17 cytokines in chronic lung diseases
The IL-17 receptor IL-17RE mediates polyIC-induced exacerbation of experimental allergic asthma
Background: The interleukin 17 receptor E (IL-17RE) is specific for the epithelial cytokine interleukin-17C (IL-17C).
Asthma exacerbations are frequently caused by viral infections. Polyinosinic:polycytidylic acid (pIC) mimics viral
infections through binding to pattern recognition receptors (e.g. TLR-3). We and others have shown that pIC
induces the expression of IL-17C in airway epithelial cells. Using different mouse models, we aimed to investigate
the function of IL-17RE in the development of experimental allergic asthma and acute exacerbation thereof.
Methods: Wild-type (WT) and IL-17RE deficient (Il-17re−/−
) mice were sensitized and challenged with OVA to induce
allergic airway inflammation. pIC or PBS were applied intranasally when allergic airway inflammation had been
established. Pulmonary expression of inflammatory mediators, numbers of inflammatory cells, and airway
hyperresponsiveness (AHR) were analyzed.
Results: Ablation of IL-17RE did not affect the development of OVA-induced allergic airway inflammation and AHR.
pIC induced inflammation independent of IL-17RE in the absence of allergic airway inflammation. Treatment of
mice with pIC exacerbated pulmonary inflammation in sensitized and OVA-challenged mice in an IL-17REdependent manner. The pIC-induced expression of cytokines (e.g. keratinocyte-derived chemokine (KC),
granulocyte-colony stimulating factor (G-CSF)) and recruitment of neutrophils were decreased in Il-17re−/− mice.
pIC-exacerbated AHR was partially decreased in Il-17re−/− mice.
Conclusions: Our results indicate that IL-17RE mediates virus-triggered exacerbations but does not have a function
in the development of allergic lung disease
IL-17C and IL-17RE Promote Wound Closure in a Staphylococcus aureus-Based Murine Wound Infection Model
The epithelial cytokine interleukin-17C (IL-17C) mediates inflammation through the interleukin 17 receptor E (IL-17RE). Prior studies showed a detrimental role of IL-17C in the pathogenesis
of immune-mediated skin diseases (e.g., psoriasis). Here, we examined the role of IL-17C/IL-17RE
in wound closure in a Staphylococcus aureus wound infection model. We demonstrate that wound
closure is significantly delayed in IL-17RE (Il-17re−/−)- and 17C (Il-17c−/−)-deficient mice. There
was no significant difference between WT, Il-17re−/−, and Il-17c−/− mice in the absence of infection.
Deficiency for IL-17RE and IL-17C did not significantly affect the elimination of bacteria. IL-17C
expression was increased in the epidermis of human S. aureus-infected skin. Our results indicate that
the IL-17C/IL-17RE axis contributes to the closure of infected wounds but does not contribute to the
elimination of S. aureus
Cigarette smoke and electronic cigarettes differentially activate bronchial epithelial cells
Background: The use of electronic cigarettes (ECIGs) is increasing, but the impact of ECIG-vapor on cellular processes
like inflammation or host defense are less understood. The aim of the present study was to compare the acute effects
of traditional cigarettes (TCIGs) and ECIG-exposure on host defense, inflammation, and cellular activation of cell lines
and primary differentiated human airway epithelial cells (pHBE).
Methods: We exposed pHBEs and several cell lines to TCIG-smoke or ECIG-vapor. Epithelial host defense and barrier
integrity were determined. The transcriptome of airway epithelial cells was compared by gene expression array analysis.
Gene interaction networks were constructed and differential gene expression over all groups analyzed. The expression
of several candidate genes was validated by qRT-PCR.
Results: Bacterial killing, barrier integrity and the expression of antimicrobial peptides were not affected by ECIG-vapor
compared to control samples. In contrast, TCIGs negatively affected host defense and reduced barrier integrity in a
significant way. Furthermore ECIG-exposure significantly induced IL-8 secretion from Calu-3 cells but had no effect on
NCI-H292 or primary cells. The gene expression based on array analysis distinguished TCIG-exposed cells from ECIG and
room air-exposed samples.
Conclusion: The transcriptome patterns of host defense and inflammatory genes are significantly distinct between
ECIG-exposed and TCIG-treated cells. The overall effects of ECIGs on epithelial cells are less in comparison to TCIG, and
ECIG-vapor does not affect host defense. Nevertheless, although acute exposure to ECIG-vapor induces inflammation,
and the expression of S100 proteins, long term in vivo data is needed to evaluate the chronic effects of ECIG use
Biochemical and transcriptomic evaluation of a 3D lung organoid platform for pre-clinical testing of active substances targeting senescence
Chronic lung diseases such as chronic obstructive pulmonary disease and cystic fibrosis are incurable. Epithelial
senescence, a state of dysfunctional cell cycle arrest, contributes to the progression of such diseases. Therefore,
lung epithelial cells are a valuable target for therapeutic intervention. Here, we present a 3D airway lung organoid
platform for the preclinical testing of active substances with regard to senescence, toxicity, and inflammation under
standardized conditions in a 96 well format. Senescence was induced with doxorubicin and measured by activity
of senescence associated galactosidase. Pharmaceutical compounds such as quercetin antagonized doxorubicininduced senescence without compromising organoid integrity. Using single cell sequencing, we identified a subset
of cells expressing senescence markers which was decreased by quercetin. Doxorubicin induced the expression of
detoxification factors specifically in goblet cells independent of quercetin. In conclusion, our platform enables for
the analysis of senescence-related processes and will allow the pre-selection of a wide range of compounds (e.g.
natural products) in preclinical studies, thus reducing the need for animal testing
The composition of the pulmonary microbiota in sarcoidosis - an observational study
Background: Sarcoidosis is a systemic disease of unknown etiology. The disease mechanisms are largely
speculative and may include the role microbial patterns that initiate and drive an underlying immune process. The
aim of this study was to characterize the microbiota of the lung of patients with sarcoidosis and compare its
composition and diversity with the results from patients with other interstitial lung disease (ILD) and historic
healthy controls.
Methods: Patients (sarcoidosis, n = 31; interstitial lung disease, n = 19) were recruited within the PULMOHOM study,
a prospective cohort study to characterize inflammatory processes in pulmonary diseases. Bronchoscopy of the
middle lobe or the lingula was performed and the recovered fluid was immediately sent for analysis of the
pulmonary microbiota by 16sRNA gene sequencing. Subsequent bioinformatic analysis was performed to compare
the groups.
Results: There were no significant differences between patients with sarcoidosis or other ILDs with regard to
microbiome composition and diversity. In addition, the abundance of the genera Atopobium, Fusobacterium,
Mycobacterium or Propionibacterium were not different between the two groups. There were no gross differences
to historical healthy controls.
Conclusion: The analysis of the pulmonary microbiota based on 16sRNA gene sequencing did not show a
significant dysbiosis in patients with sarcoidosis as compared to other ILD patients. These data do not exclude a
microbiological component in the pathogenesis of sarcoidosis
The Transcription Factor SpoVG Is of Major Importance for Biofilm Formation of Staphylococcus epidermidis under In Vitro Conditions, but Dispensable for In Vivo Biofilm Formation
Staphylococcus epidermidis is a common cause of device related infections on which pathogens
form biofilms (i.e., multilayered cell populations embedded in an extracellular matrix). Here, we
report that the transcription factor SpoVG is essential for the capacity of S. epidermidis to form such
biofilms on artificial surfaces under in vitro conditions. Inactivation of spoVG in the polysaccharide
intercellular adhesin (PIA) producing S. epidermidis strain 1457 yielded a mutant that, unlike its
parental strain, failed to produce a clear biofilm in a microtiter plate-based static biofilm assay. A
decreased biofilm formation capacity was also observed when 1457 ∆spoVG cells were co-cultured
with polyurethane-based peripheral venous catheter fragments under dynamic conditions, while
the cis-complemented 1457 ∆spoVG::spoVG derivative formed biofilms comparable to the levels seen
with the wild-type. Transcriptional studies demonstrated that the deletion of spoVG significantly
altered the expression of the intercellular adhesion (ica) locus by upregulating the transcription of
the ica operon repressor icaR and down-regulating the transcription of icaADBC. Electrophoretic
mobility shift assays (EMSA) revealed an interaction between SpoVG and the icaA-icaR intergenic
region, suggesting SpoVG to promote biofilm formation of S. epidermidis by modulating ica expression.
However, when mice were challenged with the 1457 ∆spoVG mutant in a foreign body infection
model, only marginal differences in biomasses produced on the infected catheter fragments between
the mutant and the parental strain were observed. These findings suggest that SpoVG is critical for the
PIA-dependent biofilm formation of S. epidermis under in vitro conditions, but is largely dispensable
for biofilm formation of this skin commensal under in vivo conditions
Predictive Role Of Body Composition Parameters In Operable Breast Cancer Patients Treated With Neoadjuvant Chemotherapy.
BACKGROUND:
Fat tissue is strongly involved in BC tumorigenesis inducing insulin resistance, chronic inflammation and hormonal changes. Computed tomography (CT) imaging instead of body mass index (BMI) gives a reliable measure of skeletal muscle mass and body fat distribution. The impact of body composition parameters (BCPs) on chemosensitivity is still debated. We examined the associations between BCPs and tumor response to neoadjuvant chemotherapy (NC) in patients treated for operable breast cancer (BC).
METHODS:
A retrospective review of BC patients treated with NC in Modena Cancer Center between 2005 and 2017 was performed. BCPs, such as subcutaneous fat area (SFA), visceral fat area (VFA), lumbar skeletal muscle index (LSMI) and liver-to-spleen (L/S) ratio were calculated by Advance workstation (General Electric), software ADW server 3.2 or 4.7. BMI and BCPs were correlated with pathological complete response (pCR) and survival outcomes.
RESULTS:
407 patients were included in the study: 55% with BMI < 25 and 45% with BMI 65 25. 137 of them had pre-treatment CT scan imagines. Overweight was significantly associated with postmenopausal status and older age. Hormonal receptor positive BC was more frequent in overweight patients (p<0.05). Postmenopausal women had higher VFA, fatty liver disease and obesity compared to premenopausal patients. No association between BMI classes and tumor response was detected. High VFA and liver steatosis were negative predictive factors for pCR (pCR rate: 36% normal VFA vs 20% high VFA, p= 0.048; no steatosis 32% vs steatosis 13%, p=0.056). Neither BMI classes nor BCPs significantly influenced overall survival and relapse-free survival.
CONCLUSION:
Visceral adiposity as well as steatosis were closely involved in chemosensitivity in BC patients treated with NC. Their measures from clinically acquired CT scans provide significant predictive information that outperform BMI value. More research is required to evaluate the relationship among adiposity site and survival outcomes