[Bacterial load of the surroundings during rigid diagnostic bronchoscopy under high frequency jet-ventilation]. / Mikrobielle Belastung der Umgebung während der Anwendung der Hochfrequenz-Jetventilation in der Bronchoskopie.

BACKGROUND: High-frequency jet ventilation (HFJV) is used in pneumological endoscopy for rigid, diagnostic, and therapeutic bronchoscopies. It is unclear to what extent the unobstructed flow of respiratory gas from the patient's lungs causes microbial contamination of the surrounding air. MATERIAL AND METHODS: After the start of the HFJV (15 min) in 16 rigid bronchoscopies, airborne pathogen measurements were taken directly at the distal endoscope outlet, at examiner height (40 cm above the endoscope outlet), at a 2 m distance from the endoscope in the room and at the supply air outlet of the examination room using an RCS air sampler. The number and type of pathogens isolated in the air samples were then determined, as well as germs in the bronchoalveolar lavage fluid (BALF) from the patient's lungs. RESULTS: An increased bacterial density (136 and 114 CFU/m3) was detected directly at the distal end of the endoscope and at examiner height at a distance of 40 cm, which decreased significantly with increasing distance from the bronchoscope (98 CFU/m3 at a distance of 2 m and 82 CFU/m3 at the supply air outlet). The most frequently detected bacteria were Staphylococcus spp., Micrococcus spp. and Bacillus spp. In the BALF, pathogens could only be cultivated in four of 16 samples, but the same pathogens were detected in the BALF and the ambient air. CONCLUSION: When performing a rigid bronchoscopy, in which patients are mechanically ventilated in a controlled manner using an open HFJV system, there is an increased pathogen load in the ambient air and therefore a potential risk for the examiner.

The Role of Staphylococcus aureus and Its Toxins in the Pathogenesis of Allergic Asthma.

Bronchial asthma is one of the most common chronic diseases worldwide and affects more than 300 million patients. Allergic asthma affects the majority of asthmatic children as well as approximately 50% of adult asthmatics. It is characterized by a Th2-mediated immune response against aeroallergens. Many aspects of the overall pathophysiology are known, while the underlying mechanisms and predisposing factors remain largely elusive today. Over the last decade, respiratory colonization with Staphylococcus aureus (S. aureus), a Gram-positive facultative bacterial pathogen, came into focus as a risk factor for the development of atopic respiratory diseases. More than 30% of the world's population is constantly colonized with S. aureus in their nasopharynx. This colonization is mostly asymptomatic, but in immunocompromised patients, it can lead to serious complications including pneumonia, sepsis, or even death. S. aureus is known for its ability to produce a wide range of proteins including toxins, serine-protease-like proteins, and protein A. In this review, we provide an overview of the current knowledge about the pathophysiology of allergic asthma and to what extent it can be affected by different toxins produced by S. aureus. Intensifying this knowledge might lead to new preventive strategies for atopic respiratory diseases.

Infection-Associated Mechanisms of Neuro-Inflammation and Neuro-Immune Crosstalk in Chronic Respiratory Diseases.

Chronic obstructive airway diseases are characterized by airflow obstruction and airflow limitation as well as chronic airway inflammation. Especially bronchial asthma and chronic obstructive pulmonary disease (COPD) cause considerable morbidity and mortality worldwide, can be difficult to treat, and ultimately lack cures. While there are substantial knowledge gaps with respect to disease pathophysiology, our awareness of the role of neurological and neuro-immunological processes in the development of symptoms, the progression, and the outcome of these chronic obstructive respiratory diseases, is growing. Likewise, the role of pathogenic and colonizing microorganisms of the respiratory tract in the development and manifestation of asthma and COPD is increasingly appreciated. However, their role remains poorly understood with respect to the underlying mechanisms. Common bacteria and viruses causing respiratory infections and exacerbations of chronic obstructive respiratory diseases have also been implicated to affect the local neuro-immune crosstalk. In this review, we provide an overview of previously described neuro-immune interactions in asthma, COPD, and respiratory infections that support the hypothesis of a neuro-immunological component in the interplay between chronic obstructive respiratory diseases, respiratory infections, and respiratory microbial colonization.

ImmunoPET/MR imaging allows specific detection of Aspergillus fumigatus lung infection in vivo.

Invasive pulmonary aspergillosis (IPA) is a life-threatening lung disease caused by the fungus Aspergillus fumigatus, and is a leading cause of invasive fungal infection-related mortality and morbidity in patients with hematological malignancies and bone marrow transplants. We developed and tested a novel probe for noninvasive detection of A. fumigatus lung infection based on antibody-guided positron emission tomography and magnetic resonance (immunoPET/MR) imaging. Administration of a [(64)Cu]DOTA-labeled A. fumigatus-specific monoclonal antibody (mAb), JF5, to neutrophil-depleted A. fumigatus-infected mice allowed specific localization of lung infection when combined with PET. Optical imaging with a fluorochrome-labeled version of the mAb showed colocalization with invasive hyphae. The mAb-based newly developed PET tracer [(64)Cu]DOTA-JF5 distinguished IPA from bacterial lung infections and, in contrast to [(18)F]FDG-PET, discriminated IPA from a general increase in metabolic activity associated with lung inflammation. To our knowledge, this is the first time that antibody-guided in vivo imaging has been used for noninvasive diagnosis of a fungal lung disease (IPA) of humans, an approach with enormous potential for diagnosis of infectious diseases and with potential for clinical translation.

Respiratory Bordetella bronchiseptica Carriage is Associated with Broad Phenotypic Alterations of Peripheral CD4⁺CD25⁺ T Cells and Differentially Affects Immune Responses to Secondary Non-Infectious and Infectious Stimuli in Mice.

The respiratory tract is constantly exposed to the environment and displays a favorable niche for colonizing microorganisms. However, the effects of respiratory bacterial carriage on the immune system and its implications for secondary responses remain largely unclear. We have employed respiratory carriage with Bordetella bronchiseptica as the underlying model to comprehensively address effects on subsequent immune responses. Carriage was associated with the stimulation of Bordetella-specific CD4⁺, CD8⁺, and CD4⁺CD25⁺Foxp3⁺ T cell responses, and broad transcriptional activation was observed in CD4⁺CD25⁺ T cells. Importantly, transfer of leukocytes from carriers to acutely B. bronchiseptica infected mice, resulted in a significantly increased bacterial burden in the recipient's upper respiratory tract. In contrast, we found that respiratory B. bronchiseptica carriage resulted in a significant benefit for the host in systemic infection with Listeria monocytogenes. Adaptive responses to vaccination and influenza A virus infection, were unaffected by B. bronchiseptica carriage. These data showed that there were significant immune modulatory processes triggered by B. bronchiseptica carriage, that differentially affect subsequent immune responses. Therefore, our results demonstrated the complexity of immune regulation induced by respiratory bacterial carriage, which can be beneficial or detrimental to the host, depending on the pathogen and the considered compartment.

A Mouse Model of Post-Stroke Pneumonia Induced by Intra-Tracheal Inoculation with Streptococcus pneumoniae.

BACKGROUND: Stroke-induced immunodeficiency increases the risk of infectious complications, which adversely affects neurological outcome. Among those, pneumonia affects as many as one third of stroke patients and is the main contributor to mortality in the post-acute phase of stroke. Experimental findings on post-stroke susceptibility to spontaneous pneumonia in mice are contradictory. Here, we established a mouse model inducing standardized bacterial pneumonia and characterized the impaired pulmonary cellular and humoral immune responses after experimental stroke. METHODS: Bacterial pneumonia was induced by intra-tracheal inoculation with Streptococcus pneumoniae at different time points after transient middle cerebral artery occlusion (MCAO). Bacterial counts in lungs and blood, histological changes, and cytokine production in the lungs were assessed. Furthermore, we investigated the effect of pneumonia on stroke outcome. RESULTS: Intra-tracheal inoculation resulted in reproducible pneumonia and bacteraemia, and demonstrated post-stroke susceptibility to streptococcal pneumonia developing with a delay of at least 24 h after MCAO. Higher bacterial counts in mice infected 3 days after stroke induction correlated with reduced neutrophil and macrophage infiltration in the lungs and lower levels of pro-inflammatory cytokines in the broncho-alveolar lavage compared to sham-operated animals. Pneumonia increased mortality without affecting brain-infiltrating leukocytes. CONCLUSIONS: In this standardized mouse model of post-stroke pneumonia, we describe attenuated leukocyte infiltration and cytokine production in response to bacterial infection in the lungs that has a profound effect on outcome.

Cellular immune reactions in the lung.

The lung constantly interacts with the environment through thousands of liters of air that are inhaled daily. This continually transports toxic chemicals and particles or pathogenic microorganisms deep into the respiratory system, posing a challenge to physicochemical barriers and the local immune system. Thus, complex structures and mechanisms have evolved to recognize and fend off environmental dangers while at the same time allowing efficient gas exchange. Here we review our current knowledge regarding cellular mechanisms of the immune system in context with the highly specialized anatomical features of the airways and especially the alveolar compartment. The focus is on fungal and viral infections, merging anatomical aspects well known to pulmonologists with fundamental immunological concepts. We discuss the specialized morphological constraints of immune cells compressed under a continuous layer of the surfactant lining within alveoli as well as the importance of functional polarization of respiratory tract epithelia. Furthermore, we summarize the different types of innate and adaptive immune cells and their relative contribution to lung homeostasis with respect to localization. Finally, we provide a list of currently unresolved questions with high relevance for the field that might serve as food for thought regarding future research directions.

Influenza A Virus Infection Predisposes Hosts to Secondary Infection with Different Streptococcus pneumoniae Serotypes with Similar Outcome but Serotype-Specific Manifestation.

Influenza A virus (IAV) and Streptococcus pneumoniae are major causes of respiratory tract infections, particularly during coinfection. The synergism between these two pathogens is characterized by a complex network of dysregulated immune responses, some of which last until recovery following IAV infection. Despite the high serotype diversity of S. pneumoniae and the serotype replacement observed since the introduction of conjugate vaccines, little is known about pneumococcal strain dependency in the enhanced susceptibility to severe secondary S. pneumoniae infection following IAV infection. Thus, we studied how preinfection with IAV alters host susceptibility to different S. pneumoniae strains with various degrees of invasiveness using a highly invasive serotype 4 strain, an invasive serotype 7F strain, and a carrier serotype 19F strain. A murine model of pneumococcal coinfection during the acute phase of IAV infection showed a significantly increased degree of pneumonia and mortality for all tested pneumococcal strains at otherwise sublethal doses. The incidence and kinetics of systemic dissemination, however, remained bacterial strain dependent. Furthermore, we observed strain-specific alterations in the pulmonary levels of alveolar macrophages, neutrophils, and inflammatory mediators ultimately affecting immunopathology. During the recovery phase following IAV infection, bacterial growth in the lungs and systemic dissemination were enhanced in a strain-dependent manner. Altogether, this study shows that acute IAV infection predisposes the host to lethal S. pneumoniae infection irrespective of the pneumococcal serotype, while the long-lasting synergism between IAV and S. pneumoniae is bacterial strain dependent. These results hold implications for developing tailored therapeutic treatment regimens for dual infections during future IAV outbreaks.

Interferon regulatory factor-1 protects from fatal neurotropic infection with vesicular stomatitis virus by specific inhibition of viral replication in neurons.

The innate immune system protects cells against invading viral pathogens by the auto- and paracrine action of type I interferon (IFN). In addition, the interferon regulatory factor (IRF)-1 can induce alternative intrinsic antiviral responses. Although both, type I IFN and IRF-1 mediate their antiviral action by inducing overlapping subsets of IFN stimulated genes, the functional role of this alternative antiviral action of IRF-1 in context of viral infections in vivo remains unknown. Here, we report that IRF-1 is essential to counteract the neuropathology of vesicular stomatitis virus (VSV). IFN- and IRF-1-dependent antiviral responses act sequentially to create a layered antiviral protection program against VSV infections. Upon intranasal infection, VSV is cleared in the presence or absence of IRF-1 in peripheral organs, but IRF-1-/- mice continue to propagate the virus in the brain and succumb. Although rapid IFN induction leads to a decline in VSV titers early on, viral replication is re-enforced in the brains of IRF-1-/- mice. While IFN provides short-term protection, IRF-1 is induced with delayed kinetics and controls viral replication at later stages of infection. IRF-1 has no influence on viral entry but inhibits viral replication in neurons and viral spread through the CNS, which leads to fatal inflammatory responses in the CNS. These data support a temporal, non-redundant antiviral function of type I IFN and IRF-1, the latter playing a crucial role in late time points of VSV infection in the brain.

Comprehensive analysis of lung macrophages and dendritic cells in two murine models of allergic airway inflammation reveals model- and subset-specific accumulation and phenotypic alterations.

Introduction: Allergic asthma has been mainly attributed to T helper type 2 (Th2) and proinflammatory responses but many cellular processes remain elusive. There is increasing evidence for distinct roles for macrophage and dendritic cell (DC) subsets in allergic airway inflammation (AAI). At the same time, there are various mouse models for allergic asthma that have been of utmost importance in identifying key inflammatory pathways in AAI but that differ in the allergen and/or route of sensitization. It is unclear whether and how the accumulation and activation of specialized macrophage and DC subsets depend on the experimental model chosen for analyses. Methods: In our study, we employed high-parameter spectral flow cytometry to comprehensively assess the accumulation and phenotypic alterations of different macrophage- and DC-subsets in the lung in an OVA- and an HDM-mediated mouse model of AAI. Results: We observed subset-specific as well as model-specific characteristics with respect to cell numbers and functional marker expression. Generally, alveolar as opposed to interstitial macrophages showed increased MHCII surface expression in AAI. Between the models, we observed significantly increased numbers of alveolar macrophages, CD103+ DC and CD11b+ DC in HDM-mediated AAI, concurrent with significantly increased airway interleukin-4 but decreased total serum IgE levels. Further, increased expression of CD80 and CD86 on DC was exclusively detected in HDM-mediated AAI. Discussion: Our study demonstrates a model-specific involvement of macrophage and DC subsets in AAI. It further highlights spectral flow cytometry as a valuable tool for their comprehensive analysis under inflammatory conditions in the lung.

Predicting Influenza A Virus Infection in the Lung from Hematological Data with Machine Learning.

The tracking of pathogen burden and host responses with minimally invasive methods during respiratory infections is central for monitoring disease development and guiding treatment decisions. Utilizing a standardized murine model of respiratory influenza A virus (IAV) infection, we developed and tested different supervised machine learning models to predict viral burden and immune response markers, i.e., cytokines and leukocytes in the lung, from hematological data. We performed independently in vivo infection experiments to acquire extensive data for training and testing of the models. We show here that lung viral load, neutrophil counts, cytokines (such as gamma interferon [IFN-γ] and interleukin 6 [IL-6]), and other lung infection markers can be predicted from hematological data. Furthermore, feature analysis of the models showed that blood granulocytes and platelets play a crucial role in prediction and are highly involved in the immune response against IAV. The proposed in silico tools pave the path toward improved tracking and monitoring of influenza virus infections and possibly other respiratory infections based on minimally invasively obtained hematological parameters. IMPORTANCE During the course of respiratory infections such as influenza, we do have a very limited view of immunological indicators to objectively and quantitatively evaluate the outcome of a host. Methods for monitoring immunological markers in a host's lungs are invasive and expensive, and some of them are not feasible to perform. Using machine learning algorithms, we show for the first time that minimally invasively acquired hematological parameters can be used to infer lung viral burden, leukocytes, and cytokines following influenza virus infection in mice. The potential of the framework proposed here consists of a new qualitative vision of the disease processes in the lung compartment as a noninvasive tool.

Ionic mitigation of CD4+ T cell metabolic fitness, Th1 central nervous system autoimmunity and Th2 asthmatic airway inflammation by therapeutic zinc.

T helper (Th) cells provide immunity to pathogens but also contribute to detrimental immune responses during allergy and autoimmunity. Th2 cells mediate asthmatic airway inflammation and Th1 cells are involved in the pathogenesis of multiple sclerosis. T cell activation involves complex transcriptional networks and metabolic reprogramming, which enable proliferation and differentiation into Th1 and Th2 cells. The essential trace element zinc has reported immunomodulatory capacity and high zinc concentrations interfere with T cell function. However, how high doses of zinc affect T cell gene networks and metabolism remained so far elusive. Herein, we demonstrate by means of transcriptomic analysis that zinc aspartate (UNIZINK), a registered pharmaceutical infusion solution with high bioavailability, negatively regulates gene networks controlling DNA replication and the energy metabolism of murine CD3/CD28-activated CD4+ T cells. Specifically, in the presence of zinc, CD4+ T cells show impaired expression of cell cycle, glycolytic and tricarboxylic acid cycle genes, which functionally cumulates in reduced glycolysis, oxidative phosphorylation, metabolic fitness and viability. Moreover, high zinc concentrations impaired nuclear expression of the metabolic transcription factor MYC, prevented Th1 and Th2 differentiation in vitro and reduced Th1 autoimmune central nervous system (CNS) inflammation and Th2 asthmatic airway inflammation induced by house dust mites in vivo. Together, we find that higher zinc doses impair the metabolic fitness of CD4+ T cells and prevent Th1 CNS autoimmunity and Th2 allergy.

Association of serum vitamin D levels with disease severity, systemic inflammation, prior lung function loss and exacerbations in a cohort of patients with chronic obstructive pulmonary disease (COPD).

BACKGROUND: Vitamin D deficiency has been associated with chronic disorders including chronic obstructive pulmonary disease (COPD) but the relationships with inflammation, exacerbations and disease progression remain unclear. METHODS: In this monocentric cross-sectional observational study we analyzed the disease status, systemic inflammation, prior exacerbation frequency and loss in lung function in relation to serum 25-hydroxyvitamin D (25-OHD) levels in a cohort of 94 patients with COPD. Serum 25-OHD, C-reactive protein, interleukin-6 and tumor necrosis factor-α were quantified. Exacerbation frequencies and sunlight exposure were assessed. These parameters were analyzed in correlation to the current forced expiratory volume in 1 s (FEV1), the individual average 3-year FEV1 decline and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage. RESULTS: We observed fair correlation between serum 25-OHD and the current FEV1 (r=0.38, P<0.001). Furthermore, mean serum 25-OHD was significantly altered between patients of GOLD stages I-IV (P=0.013). There was weak negative correlation of 25-OHD and the average annual change of the FEV1 (r=-0.26, P<0.05). Furthermore, we observed fair negative correlation between 25-OHD and C-reactive protein (r=-0.32, P<0.01) as well as weak negative correlation with interleukin-6 (r=-0.23, P<0.05). While the exacerbation frequency significantly differed between GOLD stages (P=0.04), there was no direct association between exacerbations and 25-OHD levels. CONCLUSION: Our data confirm frequent vitamin D deficiency in COPD and point out correlations between 25-OHD levels, systemic inflammation, disease severity and progression.

Chemical Conjugation of a Purified DEC-205-Directed Antibody with Full-Length Protein for Targeting Mouse Dendritic Cells In Vitro and In Vivo.

Targeted antigen delivery to cross-presenting dendritic cells (DC) in vivo efficiently induces T effector cell responses and displays a valuable approach in vaccine design. Antigen is delivered to DC via antibodies specific for endocytosis receptors such as DEC-205 that induce uptake, processing, and MHC class I- and II-presentation. Efficient and reliable conjugation of the desired antigen to a suitable antibody is a critical step in DC targeting and among other factors depends on the format of the antigen. Chemical conjugation of full-length protein to purified antibodies is one possible strategy. In the past, we have successfully established cross-linking of the model antigen ovalbumin (OVA) and a DEC-205-specific IgG2a antibody (αDEC-205) for in vivo DC targeting studies in mice. The first step of the protocol is the purification of the antibody from the supernatant of the NLDC (non-lymphoid dendritic cells)-145 hybridoma by affinity chromatography. The purified antibody is activated for chemical conjugation by sulfo-SMCC (sulfosuccinimidyl 4-[N-maleimidomethyl] cyclohexane-1-carboxylate) while at the same time the sulfhydryl-groups of the OVA protein are exposed through incubation with TCEP-HCl (tris (2-carboxyethyl) phosphine hydrochloride). Excess TCEP-HCl and sulfo-SMCC are removed and the antigen is mixed with the activated antibody for overnight coupling. The resulting αDEC-205/OVA conjugate is concentrated and freed from unbound OVA. Successful conjugation of OVA to αDEC-205 is verified by western blot analysis and enzyme-linked immunosorbent assay (ELISA). We have successfully used chemically crosslinked αDEC-205/OVA to induce cytotoxic T cell responses in the liver and to compare different adjuvants for their potential in inducing humoral and cellular immunity following in vivo targeting of DEC-205+ DC. Beyond that, such chemically coupled antibody/antigen conjugates offer valuable tools for the efficient induction of vaccine responses to tumor antigens and have been proven to be superior to classical immunization approaches regarding the prevention and therapy of various types of tumors.

Modulation of Allergic Sensitization and Allergic Inflammation by Staphylococcus aureus Enterotoxin B in an Ovalbumin Mouse Model.

The superantigen Staphylococcus aureus (S. aureus) enterotoxin B (SEB) has been proposed a central player in the associations between S. aureus nasal colonization and the development of allergic asthma. Previously, SEB has been shown to aggravate allergic sensitization and allergic airway inflammation (AAI) in experimental mouse models. Aiming at understanding the underlying immunological mechanisms, we tested the hypothesis that intranasal (i.n.) SEB-treatment divergently modulates AAI depending on the timing and intensity of the SEB-encounter. In an ovalbumin-mediated mouse model of AAI, we treated mice i.n. with 50 ng or 500 ng SEB either together with the allergic challenge or prior to the peripheral sensitization. We observed SEB to affect different hallmark parameters of AAI depending on the timing and the dose of treatment. SEB administered i.n. together with the allergic challenge significantly modulated respiratory leukocyte accumulation, intensified lymphocyte activation and, at the higher dose, induced a strong type-1 and pro-inflammatory cytokine response and alleviated airway hyperreactivity in AAI. SEB administered i.n. prior to the allergic sensitization at the lower dose significantly boosted the specific IgE response while administration of the higher dose led to a significantly reduced recruitment of immune cells, including eosinophils, to the respiratory tract and to a significantly dampened Th-2 cytokine response without inducing a Th-1 or pro-inflammatory response. We show a remarkably versatile potential for SEB to either aggravate or alleviate different parameters of allergic sensitization and AAI. Our study thereby not only highlights the complexity of the associations between S. aureus and allergic asthma but possibly even points at prophylactic and therapeutic pathways.

Resolved Influenza A Virus Infection Has Extended Effects on Lung Homeostasis and Attenuates Allergic Airway Inflammation in a Mouse Model.

Allergic airway inflammation (AAI) involves T helper cell type 2 (Th2) and pro-inflammatory responses to aeroallergens and many predisposing factors remain elusive. Influenza A virus (IAV) is a major human pathogen that causes acute respiratory infections and induces specific immune responses essential for viral clearance and resolution of the infection. Beyond acute infection, IAV has been shown to persistently affect lung homeostasis and respiratory immunity. Here we asked how resolved IAV infection affects subsequently induced AAI. Mice infected with a sublethal dose of IAV were sensitized and challenged in an ovalbumin mediated mouse model for AAI after resolution of the acute viral infection. Histological changes, respiratory leukocytes, cytokines and airway hyperreactivity were analyzed in resolved IAV infection alone and in AAI with and without previous IAV infection. More than five weeks after infection, we detected persistent pneumonia with increased activated CD4+ and CD8+ lymphocytes as well as dendritic cells and MHCII expressing macrophages in the lung. Resolved IAV infection significantly affected subsequently induced AAI on different levels including morphological changes, respiratory leukocytes and lymphocytes as well as the pro-inflammatory cytokine responses, which was clearly diminished. We conclude that IAV has exceptional persisting effects on respiratory immunity with substantial consequences for subsequently induced AAI.

Prevention of leakage due to mouth opening through applying an oral shield device (Sominpax™) during nasal CPAP therapy of patients with obstructive sleep apnea.

BACKGROUND/OBJECTIVE: The first line treatment for obstructive sleep apnea (OSA) is nasal continuous positive airway pressure (nCPAP), for which a variety of masks are available. While nasal masks (NM) are the first choice; oronasal masks (ONM) are also frequently used to prevent mouth dryness resulting from mouth opening. Our cross-sectional, prospective, randomized, un-blinded study addressed the efficacy of wearing an oral shield in addition to NM in preventing mouth leakage METHODS: Patients with OSA and established therapy using NM and complaining about mouth dryness (n = 29) underwent three polysomnographies (PSGs) using NM, ONM or a nose mask in combination with an oral shield (NMS). Mask leakage was continuously documented and objective sleep quality was assessed. RESULTS: There were significant differences in the apnea-hypopnea-index (AHI) between ONM (8.5/h; SD 6,7) and NM/nasal mask combined with oral shield device (NMS) (2.6/h; SD 2,3; 2.7/h; SD 2,6) (p < 0,05) as well as in leakage [ONM (39.7 l/min SD 12,4); NM (34.6 l/min SD 9,4); NMS (33.1 l/min SD 9,6)] (p = 0.011). Furthermore, analysis of sleep quality (NREM3) favored NM and NMS over ONM (p = 0.02). There were no significant differences between NM and NMS in any objective outcome. CONCLUSIONS: Our data consistently confirmed the NM as the first choice for continuous positive airway pressure (CPAP) therapy of OSA. Notably, we demonstrated a high potential of the oral shield for patients with mouth opening to achieve additional comfort and thereby possibly compliance, without affecting nCPAP therapy effectiveness.

The STING activator c-di-AMP exerts superior adjuvant properties than the formulation poly(I:C)/CpG after subcutaneous vaccination with soluble protein antigen or DEC-205-mediated antigen targeting to dendritic cells.

Vaccination is the most efficient strategy to protect from infectious diseases and the induction of a protective immune response not only depends on the nature of the antigen, but is also influenced by the vaccination strategy and the co-administration of adjuvants. Therefore, the precise monitoring of adjuvant candidates and their immune modulatory properties is a crucial step in vaccine development. Here, one central aspect is the induction of appropriate humoral and cellular effector mechanisms. In our study we performed a direct comparison of two promising candidates in adjuvant development, the STING activator bis-(3,5)-cyclic dimeric adenosine monophosphate (c-di-AMP) and the Toll-like receptor ligand formulation poly(I:C)/CpG. These were evaluated in C57BL/6 mice using the model antigen ovalbumin (OVA) in subcutaneous vaccination with soluble protein as well as in a dendritic cell (DC) targeting approach (αDEC-OVA). Strikingly, c-di-AMP as compared to poly(I:C)/CpG resulted in significantly higher antigen-specific IgG antibody levels when used in immunization with soluble OVA as well as in antigen targeting to DC. In vaccination with soluble OVA, c-di-AMP induced a significantly stronger CTL, Th1 and IFNγ-producing CD8+ memory T cell response than poly(I:C)/CpG. The response was CTL and Th1 cell dominated, a profile shared by both adjuvants. In the context of targeting OVA to DC, c-di-AMP induced significantly increased Th1 and Th2 cell responses as compared to poly(I:C)/CpG. Interestingly, the Th1 response dominated the overall T cell response only when c-di-AMP was used, indicating a distinct modulatory property of c-di-AMP when the DC targeting immunization approach was exploited. Taken together, we describe superior properties of c-di-AMP as compared to poly(I:C)/CpG in subcutaneous vaccination with soluble antigen as well as antigen targeting to DC. This indicates exceptionally effective adjuvant properties for c-di-AMP and provides compelling evidence of its potential for further adjuvant development, especially also when using DC targeting approaches.

Expression of COX-1, COX-2, 5-LOX and CysLT 2 in nasal polyps and bronchial tissue of patients with aspirin exacerbated airway disease.

BACKGROUND: Aspirin exacerbated respiratory disease (AERD) is a disease of the upper and lower airways. It is characterized by severe asthma, chronic sinusitis with nasal polyps (CRSwNP) and intolerance towards nonsteroidal analgesics (NSAR). Arachidonic acid (AA) metabolites play an important role in the pathogenesis of AERD. It is still unknown, whether metabolism of AA is comparable between the upper and lower airways as well as between patients with and without NSAR intolerance. OBJECTIVE: We sought to analyze differences in the expression of cyclooxygenases type 1 and 2 (COX-1, COX-2), arachidonate 5-lipoxygenase (5-LOX) and cysteinyl leukotriene receptor type 2 ( CysLT 2 ) in nasal polyps and the bronchial mucosa of patients with aspirin intolerant asthma (AIA, n = 23 ) as compared to patients with aspirin tolerant asthma (ATA, n = 17 ) and a control group with nasal polyps, but without asthma (NPwA, n = 15 ). METHODS: Tissue biopsies from nasal polyps and bronchial mucosa were obtained during surgical treatment of nasal polyps by endonasal functional endoscopic sinus surgery (FESS) under general anesthesia from intubated patients. Immunohistochemistry was used to analyze the expression of COX-1, COX-2, 5-LOX and CysLT 2 in nasal and bronchial mucosa. Categorization into the different patient groups was performed according to the patient history, clinical and laboratory data, pulmonary function and provocation tests, as well as allergy testing. RESULTS: We observed a stronger expression of 5-LOX and CysLT 2 in submucosal glands of nasal and bronchial tissue compared to epithelial expression. The expression of COX-1 and COX-2 was stronger in epithelia compared to submucosal glands. There was a similar expression of the enzymes and CysLT 2 between upper and lower airways in all patient groups. We did not detect any significant differences between the patient groups. CONCLUSIONS: The AA-metabolizing enzymes and the CysLT 2 were expressed in a very similar way in different microscopic structures in samples of the upper and lower airways of individual patients. We did not detect differences between the patient groups indicating the pathogenetic role of AA metabolism in these disorders is independent of the presence of NSAR-intolerance.