Exploring the human archaeome: its relevance for health and disease, and its complex interplay with the human immune system

This Review aims to coalesce existing knowledge on the human archaeome, a less-studied yet critical non-bacterial component of the human microbiome, with a focus on its interaction with the immune system. Despite a largely bacteria-centric focus in microbiome research, archaea present unique challenges and opportunities for understanding human health. We examine the archaeal distribution across different human body sites, such as the lower gastrointestinal tract (LGT), upper aerodigestive tract (UAT), urogenital tract (UGT), and skin. Variability in archaeal composition exists between sites; methanogens dominate the LGT, while Nitrososphaeria are prevalent on the skin and UAT. Archaea have yet to be classified as pathogens but show associations with conditions such as refractory sinusitis and vaginosis. In the LGT, methanogenic archaea play critical metabolic roles by converting bacterial end-products into methane, correlating with various health conditions, including obesity and certain cancers. Finally, this work looks at the complex interactions between archaea and the human immune system at the molecular level. Recent research has illuminated the roles of specific archaeal molecules, such as RNA and glycerolipids, in stimulating immune responses via innate immune receptors like Toll-like receptor 8 (TLR8) and 'C-type lectin domain family 4 member E' (CLEC4E; also known as MINCLE). Additionally, metabolic by-products of archaea, specifically methane, have demonstrated immunomodulatory effects through anti-inflammatory and anti-oxidative pathways. Despite these advancements, the mechanistic underpinnings of how archaea influence immune activity remain a fertile area for further investigation.

Investigating pyroptosis as a mechanism of L. major cell-to-cell spread in the human BLaER1 infection model

Leishmania is the causative agent of the tropical neglected disease leishmaniasis and infects macrophages as its definitive host cell. In order to sustain and propagate infections, Leishmania parasites have to complete cycles of exit and re-infection. Yet, the mechanism driving the parasite spread to other cells remains unclear. Recent studies reported pro-inflammatory monocytes as replicative niche of Leishmania major and showed prolonged expression of IL-1β at the site of infection, indicating an activation of the NLRP3 inflammasome and pointing toward pyroptosis as a possible mechanism of parasite spread. To address the species-specific inflammasome activation of human cells, we characterized the BLaER1 monocytes as a model for L. major infection. We found that BLaER1 monocytes support infection and activation by Leishmania parasites to the same extent as primary human macrophages. Harnessing the possibilities of this infection model, we first showed that BLaER1 GSDMD-/- cells, which carry a deletion of the pore-forming protein gasdermin D, are more resistant to pyroptotic cell death and, concomitantly, display a strongly delayed release of intracellular parasite. Using that knockout in a co-incubation assay in comparison with wild-type BLaER1 cells, we demonstrate that impairment of the pyroptosis pathway leads to lower rates of parasite spread to new host cells, thus, implicating pyroptotic cell death as a possible exit mechanism of L. major in pro-inflammatory microenvironments.

Recurrent Phases of Strict Protein Limitation Inhibit Tumor Growth and Restore Lifespan in A Drosophila Intestinal Cancer Model

Diets that restrict caloric or protein intake offer a variety of benefits, including decreasing the incidence of cancer. However, whether such diets pose a substantial therapeutic benefit as auxiliary cancer treatments remains unclear. We determined the effects of severe protein depletion on tumorigenesis in a Drosophila melanogaster intestinal tumor model, using a human RAF gain-of-function allele. Severe and continuous protein restriction significantly reduced tumor growth but resulted in premature death. Therefore, we developed a diet in which short periods of severe protein restriction alternated cyclically with periods of complete feeding. This nutritional regime reduced tumor mass, restored gut functionality, and rescued the lifespan of oncogene-expressing flies to the levels observed in healthy flies on a continuous, fully nutritious diet. Furthermore, this diet reduced the chemotherapy-induced stem cell activity associated with tumor recurrence. Transcriptome analysis revealed long-lasting changes in the expression of key genes involved in multiple major developmental signaling pathways. Overall, the data suggest that recurrent severe protein depletion effectively mimics the health benefits of continuous protein restriction, without undesired nutritional shortcomings. This provides seminal insights into the mechanisms of the memory effect required to maintain the positive effects of protein restriction throughout the phases of a full diet. Finally, the repetitive form of strict protein restriction is an ideal strategy for adjuvant cancer therapy that is useful in many tumor contexts.

Exploring Species-Specificity in TLR4/MD-2 Inhibition with Amphiphilic Lipid A Mimicking Glycolipids

The Toll-like receptor 4 (TLR4)/myeloid differentiation factor 2 (MD-2) complex is a key receptor of the innate immune system and a major driver of inflammation that is responsible for the multifaceted defense response to Gram-negative infections. However, dysfunction in the tightly regulated mechanisms of TLR4-mediated signaling leads to the uncontrolled upregulation of local and systemic inflammation, often resulting in acute or chronic disease. Therefore, the TLR4/MD-2 receptor complex is an attractive target for the design and development of anti-inflammatory therapies which aim to control the unrestrained activation of TLR4-mediated signaling. Complex structure-activity relationships and species-specificity behind ligand recognition by the TLR4/MD-2 complex complicate the development of MD-2-specific TLR4 antagonists. The restriction of the conformational flexibility of the disaccharide polar head group is one of the key structural features of the newly developed lipid A-mimicking glycophospholipids, which are potential inhibitors of TLR4-mediated inflammation. Since phosphorylation has a crucial influence on MD-2-ligand interaction, glycolipids with variable numbers and positioning of phosphate groups were synthesized and evaluated for their ability to inhibit TLR4-mediated pro-inflammatory signaling in human and murine immune cells. A bis-phosphorylated glycolipid was found to have nanomolar antagonist activity on human TLR4 while acting as a partial agonist on murine TLR4. The glycolipid inhibited mTLR4/MD-2-mediated cytokine release, acting as an antagonist in the presence of lipopolysaccharide (LPS), but at the same time induced low-level cytokine production.

Therapeutic Targeting of TLR4 for Inflammation, Infection, and Cancer: A Perspective for Disaccharide Lipid A Mimetics

The Toll-like receptor 4 (TLR4) signaling pathway plays a central role in the prompt defense against infectious challenge and provides immediate response to Gram-negative bacterial infection. The TLR4/MD-2 complex can sense and respond to various pathogen-associated molecular patterns (PAMPs) with bacterial lipopolysaccharide (LPS) being the most potent and the most frequently occurring activator of the TLR4-mediated inflammation. TLR4 is believed to be both a friend and foe since improperly regulated TLR4 signaling can result in the overactivation of immune responses leading to sepsis, acute lung injury, or pathologic chronic inflammation involved in cancer and autoimmune disease. TLR4 is also considered a legitimate target for vaccine adjuvant development since its activation can boost the adaptive immune responses. The dual action of the TLR4 complex justifies the efforts in the development of both TLR4 antagonists as antisepsis drug candidates or remedies for chronic inflammatory diseases and TLR4 agonists as vaccine adjuvants or immunotherapeutics. In this review, we provide a brief overview of the biochemical evidences for possible pharmacologic applications of TLR4 ligands as therapeutics and report our systematic studies on the design, synthesis, and immunobiological evaluation of carbohydrate-based TLR4 antagonists with nanomolar affinity for MD-2 as well as disaccharide-based TLR4 agonists with picomolar affinity for the TLR4/MD-2 complex.

Lipid A Mimetics Based on Unnatural Disaccharide Scaffold as Potent TLR4 Agonists for Prospective Immunotherapeutics and Adjuvants

TLR4 is a key pattern recognition receptor that can sense pathogen- and danger- associated molecular patterns to activate the downstream signaling pathways which results in the upregulation of transcription factors and expression of interferons and cytokines to mediate protective pro-inflammatory responses involved in immune defense. Bacterial lipid A is the primary TLR4 ligand with very complex, species-specific, and barely predictable structure-activity relationships. Given that therapeutic targeting of TLR4 is an emerging tool for management of a variety of human diseases, the development of novel TLR4 activating biomolecules other than lipid A is of vast importance. We report on design, chemical synthesis and immunobiology of novel glycan-based lipid A-mimicking molecules that can activate human and murine TLR4-mediated signaling with picomolar affinity. Exploiting crystal structure - based design we have created novel disaccharide lipid A mimetics (DLAMs) where the inherently flexible β(1→6)-linked diglucosamine backbone of lipid A is exchanged with a conformationally restrained non-reducing βGlcN(1↔1')βGlcN scaffold. Excellent stereoselectivity in a challenging β,β-1,1' glycosylation was achieved by tuning the reactivities of donor and acceptor molecules using protective group manipulation strategy. Divergent streamlined synthesis of β,β-1,1'-linked diglucosamine-derived glycolipids entailing multiple long-chain (R)-3- acyloxyacyl residues and up two three phosphate groups was developed. Specific 3D-molecular shape and conformational rigidity of unnatural β,β-1,1'-linked diglucosamine combined with carefully optimized phosphorylation and acylation pattern ensured efficient induction of the TLR4-mediated signaling in a species-independent manner.

TLR8 is activated by 5'-methylthioinosine, a Plasmodium falciparum-derived intermediate of the purine salvage pathway

The innate immune recognition of the malaria-causing pathogen Plasmodium falciparum (P. falciparum) is not fully explored. Here, we identify the nucleoside 5'-methylthioinosine (MTI), a Plasmodium-specific intermediate of the purine salvage pathway, as a pathogen-derived Toll-like receptor 8 (TLR8) agonist. Co-incubation of MTI with the TLR8 enhancer poly(dT) as well as synthetic or P. falciparum-derived RNA strongly increase its stimulatory activity. Of note, MTI generated from methylthioadenosine (MTA) by P. falciparum lysates activates TLR8 when MTI metabolism is inhibited by immucillin targeting the purine nucleoside phosphorylase (PfPNP). Importantly, P. falciparum-infected red blood cells incubated with MTI or cultivated with MTA and immucillin lead to TLR8-dependent interleukin-6 (IL-6) production in human monocytes. Our data demonstrate that the nucleoside MTI is a natural human TLR8 ligand with possible in vivo relevance for innate sensing of P. falciparum.

WNT6/ACC2-induced storage of triacylglycerols in macrophages is exploited by Mycobacterium tuberculosis

In view of emerging drug-resistant tuberculosis (TB), host-directed adjunct therapies are urgently needed to improve treatment outcomes with currently available anti-TB therapies. One approach is to interfere with the formation of lipid-laden "foamy" macrophages in the host, as they provide a nutrient-rich host cell environment for Mycobacterium tuberculosis (Mtb). Here, we provide evidence that Wnt family member 6 (WNT6), a ligand of the evolutionarily conserved Wingless/Integrase 1 (WNT) signaling pathway, promotes foam cell formation by regulating key lipid metabolic genes including acetyl-CoA carboxylase 2 (ACC2) during pulmonary TB. Using genetic and pharmacological approaches, we demonstrated that lack of functional WNT6 or ACC2 significantly reduced intracellular triacylglycerol (TAG) levels and Mtb survival in macrophages. Moreover, treatment of Mtb-infected mice with a combination of a pharmacological ACC2 inhibitor and the anti-TB drug isoniazid (INH) reduced lung TAG and cytokine levels, as well as lung weights, compared with treatment with INH alone. This combination also reduced Mtb bacterial numbers and the size of mononuclear cell infiltrates in livers of infected mice. In summary, our findings demonstrate that Mtb exploits WNT6/ACC2-induced storage of TAGs in macrophages to facilitate its intracellular survival, a finding that opens new perspectives for host-directed adjunctive treatment of pulmonary TB.

Constitutive immune activity promotes JNK- and FoxO-dependent remodeling of Drosophila airways

Extensive remodeling of the airways is a major characteristic of chronic inflammatory lung diseases such as asthma or chronic obstructive pulmonary disease (COPD). To elucidate the importance of a deregulated immune response in the airways for remodeling processes, we established a matching Drosophila model. Here, triggering the Imd (immune deficiency) pathway in tracheal cells induced organ-wide remodeling. This structural remodeling comprises disorganization of epithelial structures and comprehensive epithelial thickening. We show that these structural changes do not depend on the Imd pathway's canonical branch terminating on nuclear factor κB (NF-κB) activation. Instead, activation of a different segment of the Imd pathway that branches off downstream of Tak1 and comprises activation of c-Jun N-terminal kinase (JNK) and forkhead transcription factor of the O subgroup (FoxO) signaling is necessary and sufficient to mediate the observed structural changes of the airways. Our findings imply that targeting JNK and FoxO signaling in the airways could be a promising strategy to interfere with disease-associated airway remodeling processes.

Tailored Modulation of Cellular Pro-inflammatory Responses With Disaccharide Lipid A Mimetics

Pro-inflammatory signaling mediated by Toll-like receptor 4 (TLR4)/myeloid differentiation-2 (MD-2) complex plays a crucial role in the instantaneous protection against infectious challenge and largely contributes to recovery from Gram-negative infection. Activation of TLR4 also boosts the adaptive immunity which is implemented in the development of vaccine adjuvants by application of minimally toxic TLR4 activating ligands. The modulation of pro-inflammatory responses via the TLR4 signaling pathway was found beneficial for management of acute and chronic inflammatory disorders including asthma, allergy, arthritis, Alzheimer disease pathology, sepsis, and cancer. The TLR4/MD-2 complex can recognize the terminal motif of Gram-negative bacterial lipopolysaccharide (LPS)—a glycophospholipid lipid A. Although immense progress in understanding the molecular basis of LPS-induced TLR4-mediated signaling has been achieved, gradual, and predictable TLR4 activation by structurally defined ligands has not yet been attained. We report on controllable modulation of cellular pro-inflammatory responses by application of novel synthetic glycolipids—disaccharide-based lipid A mimetics (DLAMs) having picomolar affinity for TLR4/MD-2. Using crystal structure inspired design we have developed endotoxin mimetics where the inherently flexible β(1 → 6)-linked diglucosamine backbone of lipid A is replaced by a conformationally restricted α,α-(1↔1)-linked disaccharide scaffold. The tertiary structure of the disaccharide skeleton of DLAMs mirrors the 3-dimensional shape of TLR4/MD-2 bound E. coli lipid A. Due to exceptional conformational rigidity of the sugar scaffold, the specific 3D organization of DLAM must be preserved upon interaction with proteins. These structural factors along with specific acylation and phosphorylation pattern can ensure picomolar affinity for TLR4 and permit efficient dimerization of TLR4/MD-2/DLAM complexes. Since the binding pose of lipid A in the binding pocket of MD-2 (±180°) is crucial for the expression of biological activity, the chemical structure of DLAMs was designed to permit a predefined binding orientation in the binding groove of MD-2, which ensured tailored and species-independent (human and mice) TLR4 activation. Manipulating phosphorylation and acylation pattern at the sugar moiety facing the secondary dimerization interface allowed for adjustable modulation of the TLR4-mediated signaling. Tailored modulation of cellular pro-inflammatory responses by distinct modifications of the molecular structure of DLAMs was attained in primary human and mouse immune cells, lung epithelial cells and TLR4 transfected HEK293 cells.

Lipopolysaccharide Recognition in the Crossroads of TLR4 and Caspase-4/11 Mediated Inflammatory Pathways

The innate immune response to lipopolysaccharide is essential for host defense against Gram-negative bacteria. In response to bacterial infection, the TLR4/MD-2 complex that is expressed on the surface of macrophages, monocytes, dendritic, and epithelial cells senses picomolar concentrations of endotoxic LPS and triggers the production of various pro-inflammatory mediators. In addition, LPS from extracellular bacteria which is either endocytosed or transfected into the cytosol of host cells or cytosolic LPS produced by intracellular bacteria is recognized by cytosolic proteases caspase-4/11 and hosts guanylate binding proteins that are involved in the assembly and activation of the NLRP3 inflammasome. All these events result in the initiation of pro-inflammatory signaling cascades directed at bacterial eradication. However, TLR4-mediated signaling and caspase-4/11-induced pyroptosis are largely involved in the pathogenesis of chronic and acute inflammation. Both extra- and intracellular LPS receptors—TLR4/MD-2 complex and caspase-4/11, respectively—are able to directly bind the lipid A motif of LPS. Whereas the structural basis of lipid A recognition by the TLR4 complex is profoundly studied and well understood, the atomic mechanism of LPS/lipid A interaction with caspase-4/11 is largely unknown. Here we describe the LPS-induced TLR4 and caspase-4/11 mediated signaling pathways and their cross-talk and scrutinize specific structural features of the lipid A motif of diverse LPS variants that have been reported to activate caspase-4/11 or to induce caspase-4/11 mediated activation of NLRP3 inflammasome (either upon transfection of LPS in vitro or upon infection of cell cultures with intracellular bacteria or by LPS as a component of the outer membrane vesicles). Generally, inflammatory caspases show rather similar structural requirements as the TLR4/MD-2 complex, so that a “basic” hexaacylated bisphosphorylated lipid A architecture is sufficient for activation. However, caspase-4/11 can sense and respond to much broader variety of lipid A variants compared to the very “narrow” specificity of TLR4/MD-2 complex as far as the number and the length of lipid chains attached at the diglucosamine backbone of lipid A is concerned. Besides, modification of the lipid A phosphate groups with positively charged appendages such as phosphoethanolamine or aminoarabinose could be essential for the interaction of lipid A/LPS with inflammatory caspases and related proteins.

Driver mutations in major lung cancer oncogenes can be analyzed in Drosophila models

Lung cancer remains the leading cause of cancer-associated mortality. Despite recent promising achievements, the overall prognosis remains very poor. In order to integrate the advantages of adapted, transgenic animal models with a high-throughput procedure on the one hand and compliance with the 3R principles on the other hand, we have established and evaluated appropriate Drosophila models. To achieve this goal, we ectopically expressed oncogenes representing the most important driver mutations exclusively in the airway system. These oncogenes were either the human oncogenes or the corresponding Drosophila orthologs. We concentrated on two complementary read-out systems, 1) early larval lethality and 2) quantification of concurrently expressed GFP as a proxy for tumor mass. We could show that ectopic expression of EgfrCA, RasV12, Raf, Rolled (MAPK), PI3K92E, Alk, Akt and Arm can induce early lethality. Thus, they can be used in a straight-forward high-throughput screening approach and can replace mouse models to a considerable extent. Moreover, we could also show that measurement of tumor mass by a concurrently expressed marker (GFP) can be used to detect positive treatment results. Our results show that our Drosophila system provides a superb in vivo inver­tebrate screening system amenable to high-throughput approaches and thus effectively complements the toolbox for the development of novel anti-lung cancer treatments, while complying with the 3R principles.

2'-O-methylation within prokaryotic and eukaryotic tRNA inhibits innate immune activation by endosomal Toll-like receptors but does not affect recognition of whole organisms

Bacterial RNA has emerged as an important activator of innate immune responses by stimulating Toll-like receptors TLR7 and TLR8 in humans. Guanosine 2'-O-methylation at position 18 (Gm18) in bacterial tRNA was shown to antagonize tRNA-induced TLR7/8 activation, suggesting a potential role of Gm18 as an immune escape mechanism. This modification also occurs in eukaryotic tRNA, yet a physiological immune function remained to be tested. We therefore set out to investigate the immune modulatory role of Gm18 in both prokaryotic and eukaryotic microorganisms, Escherichia coli and Saccharomyces cerevisiae, and in human cells. Using RiboMethSeq analysis we show that mutation of trmH in E. coli, trm3 in S. cereviase, and CRISPR/Cas9-induced knockout of TARBP1 in H. sapiens results in loss of Gm18 within tRNA. Lack of Gm18 across the kingdoms resulted in increased immunostimulation of peripheral blood mononuclear cells when activated by tRNA preparations. In E. coli, lack of 2'-O-methyltransferase trmH also enhanced immune stimulatory properties by whole cellular RNA. In contrast, lack of Gm18 in yeasts and human cells did not affect immunostimulation by whole RNA preparations. When using live E. coli bacteria, lack of trmH did not affect overall immune stimulation although we detected a defined TLR8/RNA-dependent gene expression signature upon E. coli infection. Together, these results demonstrate that Gm18 is a global immune inhibitory tRNA modification across the kingdoms and contributes to tRNA recognition by innate immune cells, but as an individual modification has insufficient potency to modulate recognition of the investigated microorganisms.

An EGFR-Induced Drosophila Lung Tumor Model Identifies Alternative Combination Treatments

Lung cancer is the leading cause of cancer-associated mortality. Mutations in the EGFR gene are among the most important inducers of lung tumor development, but success of personalized therapies is still limited because of toxicity or developing resistances. We expressed constitutively active EGFR (EGFR^CA) exclusively in the airway system of Drosophila melanogaster and performed comprehensive phenotyping. Ectopic expression of EGFR^CA induced massive hyper- and metaplasia, leading to early death. We used the lethal phenotype as a readout and screened a library of FDA-approved compounds and found that among the 1,000 compounds, only the tyrosine kinase inhibitors (TKI) afatinib, gefitinib, and ibrutinib rescued lethality in a whole-animal screening approach. Furthermore, we screened the library in the presence of a subtherapeutic afatinib dose and identified bazedoxifene as a synergistically acting compound that rescues EGFR-induced lethality. Our findings highlight the potential of Drosophila-based whole-animal screening approaches not only to identify specific EGFR inhibitors but also to discover compounds that act synergistically with known TKIs. Moreover, we showed that targeting the EGFR together with STAT-signaling is a promising strategy for lung tumor treatment.

Lipophilic Allergens, Different Modes of Allergen-Lipid Interaction and Their Impact on Asthma and Allergy

Molecular allergology research has provided valuable information on the structure and function of single allergenic molecules. There are several allergens in food and inhalant allergen sources that are able to interact with lipid ligands via different structural features: hydrophobic pockets, hydrophobic cavities, or specialized domains. For only a few of these allergens information on their associated ligands is already available. Several of the allergens are clinically relevant, so that it is highly probable that the individual structural features with which they interact with lipids have a direct effect on their allergenic potential, and thus on allergy development. There is some evidence for a protective effect of lipids delaying the enzymatic digestion of the peanut (Arachis hypogaea) allergen Ara h 8 (hydrophobic pocket), probably allowing this molecule to get to the intestinal immune system intact (sensitization). Oleosins from different food allergen sources are part of lipid storage organelles and potential marker allergens for the severity of the allergic reaction. House dust mite (HDM), is more often associated with allergic asthma than other sources of inhalant allergens. In particular, lipid-associated allergens from Dermatophagoides pteronyssinus which are Der p 2, Der p 5, Der p 7, Der p 13, Der p 14, and Der p 21 have been reported to be associated with severe allergic reactions and respiratory symptoms such as asthma. The exact mechanism of interaction of these allergens with lipids still has to be elucidated. Apart from single allergens glycolipids have been shown to directly induce allergic inflammation. Several-in parts conflicting-data exist on the lipid (and allergen) and toll-like receptor interactions. For only few single allergens mechanistic studies were performed on their interaction with the air-liquid interface of the lungs, in particular with the surfactant components SP-A and SP-D. The increasing knowledge on protein-lipid-interaction for lipophilic and hydrophobic food and inhalant allergens on the basis of their particular structure, of their capacity to be integral part of membranes (like the oleosins), and their ability to interact with membranes, surfactant components, and transport lipids (like the lipid transfer proteins) are essential to eventually clarify allergy and asthma development.

RNA is taking its Toll: Impact of RNA-specific Toll-like receptors on health and disease

RNA-sensing Toll-like receptors (TLRs) are often described as antiviral receptors of the innate immune system. However, the past decade has shown that the function and relevance of these receptors are far more complex. They were found to be essential for the detection of various bacterial, archaeal, and eukaryotic microorganisms and facilitate the discrimination between dead and living microbes. The cytokine and interferon response profile that is triggered has the potential to improve the efficacy of next-generation vaccines and may prevent the development of asthma and allergy. Nevertheless, the ability to recognize foreign RNA comes with a cost as also damaged host cells can release nucleic acids that might induce an inappropriate immune response. Thus, it is not surprising that RNA-sensing TLRs play a key role in various autoimmune diseases. However, promising new inhibitors and antagonists are on the horizon to improve their treatment.

Disaccharide-Based Anionic Amphiphiles as Potent Inhibitors of Lipopolysaccharide-Induced Inflammation

Despite significant advances made in the last decade in the understanding of molecular mechanisms of sepsis and in the development of clinically relevant therapies, sepsis remains the leading cause of mortality in intensive care units with increasing incidence worldwide. Toll-like receptor 4 (TLR4)-a transmembrane pattern-recognition receptor responsible for propagating the immediate immune response to Gram-negative bacterial infection-plays a central role in the pathogenesis of sepsis and chronic inflammation-related disorders. TLR4 is complexed with the lipopolysaccharide (LPS)-sensing protein myeloid differentiation-2 (MD-2) which represents a preferred target for establishing new anti-inflammatory treatment strategies. Herein we report the development, facile synthesis, and biological evaluation of novel disaccharide-based TLR4⋅MD-2 antagonists with potent anti-endotoxic activity at micromolar concentrations. A series of synthetic anionic glycolipids entailing amide-linked β-ketoacyl lipid residues was prepared in a straightforward manner by using a single orthogonally protected nonreducing diglucosamine scaffold. Suppression of the LPS-induced release of interleukin-6 and tumor necrosis factor was monitored and confirmed in human immune cells (MNC and THP1) and mouse macrophages. Structure-activity relationship studies and molecular dynamics simulations revealed the structural basis for the high-affinity interaction between anionic glycolipids and MD-2, and highlighted two compounds as leads for the development of potential anti-inflammatory therapeutics.

Synthetic glycan-based TLR4 agonists targeting caspase-4/11 for the development of adjuvants and immunotherapeutics

The skewed molecular shape of the rigid α,α-(1↔1′)-linked disaccharide core of novel synthetic anionic glycan-based immunostimulants is accountable for potent and adjustable TLR4-mediated signaling which is dissociable from the induction of caspase-11 protease activity.

Gram-negative bacterial lipopolysaccharide (LPS)-induced Toll-like receptor 4 (TLR4) mediated pro-inflammatory signaling plays a key role in immunoprotection against infectious challenges and boosts adaptive immunity, whereas the activation of the cytosolic LPS receptor caspase-4/11 leads to cell death by pyroptosis and is deeply implicated in the development of sepsis. Despite tremendous advances in the understanding of the LPS–TLR4 interaction, predictably regulated TLR4 activation has not yet been achieved. The structural basis for the induction of caspase-4/11 protease activity by LPS is currently unknown. The modulation of innate and adaptive immune responses through the controlled induction of TLR4 signaling without triggering caspase-4/11 activity would open novel perspectives in the development of safe vaccine adjuvants and immunotherapeutics. We report the discovery of highly potent glycan-based immunostimulants with picomolar affinity for TLR4 which interact with caspase-4/11 and promote caspase-4/11 oligomerization while abolishing caspase-11 protease activity. The rigidity and twisted molecular shape of the α,α-(1↔1′)-linked disaccharide core of synthetic LPS mimicking anionic glycolipids accounted for both species-independent and adjustable TLR4-mediated NF-κB signaling and the modulation of caspase-4/11 activation. By the use of crystal structure based design and advanced synthetic chemistry we created a set of versatile probes for studying the structural basis of caspase-4/11 activation and established a chemical strategy for controllable TLR4 mediated cytokine release which is dissociable from the induction of caspase-11 protease activity.

Influences of environmental bacteria and their metabolites on allergies, asthma, and host microbiota

The prevalence of allergic diseases and asthma has dramatically increased over the last decades, resulting in a high burden for patients and healthcare systems. Thus, there is an unmet need to develop preventative strategies for these diseases. Epidemiological studies show that reduced exposure to environmental bacteria in early life (eg, birth by cesarean section, being formula-fed, growing up in an urban environment or with less contact to various persons) is associated with an increased risk to develop allergies and asthma later in life. Conversely, a reduced risk for asthma is consistently found in children growing up on traditional farms, thereby being exposed to a wide spectrum of microbes. However, clinical studies with bacteria to prevent allergic diseases are still rare and to some extent contradicting. A detailed mechanistic understanding of how environmental microbes influence the development of the human microbiome and the immune system is important to enable the development of novel preventative approaches that are based on the early modulation of the host microbiota and immunity. In this mini-review, we summarize current knowledge and experimental evidence for the potential of bacteria and their metabolites to be used for the prevention of asthma and allergic diseases.

The Human-Associated Archaeon Methanosphaera stadtmanae Is Recognized through Its RNA and Induces TLR8-Dependent NLRP3 Inflammasome Activation

The archaeon Methanosphaera stadtmanae is a member of the gut microbiota; yet, the molecular cross-talk between archaea and the human immune system and its potential contribution to inflammatory diseases has not been evaluated. Although archaea are as bacteria prokaryotes, they form a distinct domain having unique features such as different cell wall structures and membrane lipids. So far, no microbe-associated molecular patterns of archaea which activate innate immune receptors have been identified. By stimulating human myeloid cells with M. stadtmanae and purified archaeal nucleic acids, we identified both the microorganism and its RNA as potent stimuli for the innate immune system. To dissect the recognition and activation pathways induced by M. stadtmanae, human monocytic BLaER1 knockout cells were generated using the CRISPR/Cas9 system targeting components of TLR and inflammasome signaling. While the recognition of M. stadtmanae is mediated by TLR7 and TLR8, activation of the NLRP3 inflammasome depends solely on TLR8 engagement. Notably, this process resembles hallmarks of both the canonical and the recently described alternative inflammasome activation. Thus, we have demonstrated for the first time the specific recognition of and response to an archaeon by human cells at the molecular level.

Plasmodium falciparum Heat Shock Protein 70 Lacks Immune Modulatory Activity

BACKGROUND

Heat shock protein 70 (Hsp70) family are conserved molecules that constitute a major part of the cell's protein folding machinery. The role of Hsp70s of parasitic origin in host cell immune modulation has remained contentious. This is largely due to the fact that several studies implicating Hsp70 in immune modulation rely on the use of recombinant protein derived from bacteria which is often fraught with lipopolysaccharide (LPS) contamination. For this reason, there is need to clarify the role of parasite Hsp70 in modulating host immune cells.

OBJECTIVE

The current study sought to investigate the role of Plasmodium falciparum Hsp70 (PfHsp70) in immune modulation.

METHOD

We expressed recombinant PfHsp70 using three bacterial expression hosts: E. coli XL1 Blue, E. coli ClearColi BL21 and Brevibacillus choshinensis, respectively. We further investigated the immunostimulatory capability of PfHsp70 by monitoring cytokine production by murine immune cells cultured in the presence of the protein.

RESULTS

Recombinant PfHsp70 produced using E. coli XL1 Blue expression host induced IL6 and IL8 cytokines. On the other hand, PfHsp70 produced in E. coli ClearColi and B. choshinensis expression systems was associated with no detectable traces of LPS and exhibited no immunomodulatory activity.

CONCLUSION

Our findings demonstrate that PfHsp70 does not possess immunomodulatory function. Furthermore, our study further confirm E. coli ClearColi and B. choshinensis as appropriate expression systems for the production of LPS-free recombinant protein.

Biological effects of carbon black nanoparticles are changed by surface coating with polycyclic aromatic hydrocarbons

Background

Carbon black nanoparticles (CBNP) are mainly composed of carbon, with a small amount of other elements (including hydrogen and oxygen). The toxicity of CBNP has been attributed to their large surface area, and through adsorbing intrinsically toxic substances, such as polycyclic aromatic hydrocarbons (PAH). It is not clear whether a PAH surface coating changes the toxicological properties of CBNP by influencing their physicochemical properties, through the specific toxicity of the surface-bound PAH, or by a combination of both.

Methods

Printex^®90 (P90) was used as CBNP; the comparators were P90 coated with either benzo[a]pyrene (BaP) or 9-nitroanthracene (9NA), and soot from acetylene combustion that bears various PAHs on the surface (AS-PAH). Oxidative stress and IL-8/KC mRNA expression were determined in A549 and bronchial epithelial cells (16HBE14o-, Calu-3), mouse intrapulmonary airways and tracheal epithelial cells. Overall toxicity was tested in a rat inhalation study according to Organization for Economic Co-operation and Development (OECD) criteria. Effects on cytochrome monooxygenase (Cyp) mRNA expression, cell viability and mucociliary clearance were determined in acute exposure models using explanted murine trachea.

Results

All particles had similar primary particle size, shape, hydrodynamic diameter and ζ-potential. All PAH-containing particles had a comparable specific surface area that was approximately one third that of P90. AS-PAH contained a mixture of PAH with expected higher toxicity than BaP or 9NA. PAH-coating reduced some effects of P90 such as IL-8 mRNA expression and oxidative stress in A549 cells, granulocyte influx in the in vivo OECD experiment, and agglomeration of P90 and mucus release in the murine trachea ex vivo. Furthermore, P90-BaP decreased particle transport speed compared to P90 at 10 μg/ml. In contrast, PAH-coating induced IL-8 mRNA expression in bronchial epithelial cell lines, and Cyp mRNA expression and apoptosis in tracheal epithelial cells. In line with the higher toxicity compared to P90-BaP and P90-9NA, AS-PAH had the strongest biological effects both ex vivo and in vivo.

Conclusions

Our results demonstrate that the biological effect of CBNP is determined by a combination of specific surface area and surface-bound PAH, and varies in different target cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12989-017-0189-1) contains supplementary material, which is available to authorized users.

4th Pediatric Allergy and Asthma Meeting (PAAM)

WORKSHOP 4: Challenging clinical scenarios (CS01–CS06)

CS01 Bullous lesions in two children: solitary mastocytoma

S. Tolga Yavuz, Ozan Koc, Ali Gungor, Faysal Gok

CS02 Multi-System Allergy (MSA) of cystic fibrosis: our institutional experience

Jessica Hawley, Christopher O’Brien, Matthew Thomas, Malcolm Brodlie, Louise Michaelis

CS03 Cold urticaria in pediatric age: an invisible cause for severe reactions

Inês Mota, Ângela Gaspar, Susana Piedade, Graça Sampaio, José Geraldo Dias, Miguel Paiva, Mário Morais-Almeida

CS04 Angioedema with C1 inhibitor deficiency in a girl: a challenge diagnosis

Cristina Madureira, Tânia Lopes, Susana Lopes, Filipa Almeida, Alexandra Sequeira, Fernanda Carvalho, José Oliveira

CS05 A child with unusual multiple organ allergy disease: what is the primer?

Fabienne Gay-Crosier

CS06 A case of uncontrolled asthma in a 6-year-old patient

Ioana-Valentina Nenciu, Andreia Florina Nita, Alexandru Ulmeanu, Dumitru Oraseanu, Carmen Zapucioiu

ORAL ABSTRACT SESSION 1: Food allergy (OP01–OP06)

OP01 Food protein-induced enterocolitis syndrome: oral food challenge outcomes for tolerance evaluation in a Pediatric Hospital

Adrianna Machinena, Olga Domínguez Sánchez, Montserrat Alvaro Lozano, Rosa Jimenez Feijoo, Jaime Lozano Blasco, Mònica Piquer Gibert, Mª Teresa Giner Muñoz, Marcia Dias da Costa, Ana Maria Plaza Martín

OP02 Characteristics of infants with food protein-induced enterocolitis syndrome and allergic proctocolitis

Ebru Arik Yilmaz, Özlem Cavkaytar, Betul Buyuktiryaki, Ozge Soyer, Cansin Sackesen

OP03 The clinical and immunological outcomes after consumption of baked egg by 1–5 year old egg allergic children: results of a randomised controlled trial

MerrynNetting, Adaweyah El-Merhibi, Michael Gold, PatrickQuinn, IrmeliPenttila, Maria Makrides

OP04 Oral immunotherapy for treatment of egg allergy using low allergenic, hydrolysed egg

Stavroula Giavi, Antonella Muraro, Roger Lauener, Annick Mercenier, Eugen Bersuch, Isabella M. Montagner, Maria Passioti, Nicolò Celegato, Selina Summermatter, Sophie Nutten, Tristan Bourdeau, Yvonne M. Vissers, Nikolaos G. Papadopoulos

OP05 Chemical modification of a peanut extract results in an increased safety profile while maintaining efficacy

Hanneke van der Kleij, Hans Warmenhoven, Ronald van Ree, Raymond Pieters, Dirk Jan Opstelten, Hans van Schijndel, Joost Smit

OP06 Administration of the yellow fever vaccine in egg allergic children

Roisin Fitzsimons, Victoria Timms, George Du Toit

ORAL ABSTRACT SESSION 2: Asthma (OP07–OP12)

OP07 Previous exacerbation is the most important risk factor for future exacerbations in school-age children with asthma

S. Tolga Yavuz, Guven Kaya, Mustafa Gulec, Mehmet Saldir, Osman Sener, Faysal Gok

OP08 Comparative study of degree of severity and laboratory changes between asthmatic children using different acupuncture modalities

Nagwa Hassan, Hala Shaaban, Hazem El-Hariri, Ahmed Kamel Inas E. Mahfouz

OP09 The concentration of exhaled carbon monoxide in asthmatic children with different controlled stadium

Papp Gabor, Biro Gabor, Kovacs Csaba

OP10 Effect of vitamin D3 supplementation during pregnancy on risk of persistent wheeze in the offspring: a randomised clinical trial

Bo Chawes, Klaus Bønnelykke, Jakob Stokholm, Lene Heickendorff, Susanne Brix, Morten Rasmussen, Hans Bisgaard

OP11 Lung function development in childhood

Henrik Wegener Hallas, Bo Chawes, Lambang Arianto, Hans Bisgaard

OP12 Is the effect of maternal and paternal asthma different in female and male children before puberty?

Maike Pincus, Thomas Keil, Andreas Reich, Ulrich Wahn, Susanne Lau, Linus Grabenhenrich

ORAL ABSTRACT SESSION 3: Epidemiology—genetics (OP13–OP18)

OP13 Lifestyle is associated with incidence and category of allergen sensitisation: the ALADDIN birth cohort

Sara Fagerstedt, Helena Marell Hesla, Emelie Johansson, Helen Rosenlund, Axel Mie, Annika Scheynius, Johan Alm

OP15 Maternal filaggrin mutations increase the risk of atopic dermatitis in children: an effect independent of mutation inheritance

Jorge Esparza-Gordillo, Anja Matanovic, Ingo Marenholz, Anja Bauerfeind, Klaus Rohde, Katja Nemat, Min-Ae Lee-Kirsch, Magnus Nordenskjöld, Marten C. G. Winge, Thomas Keil, Renate Krüger, Susanne Lau, Kirsten Beyer, Birgit Kalb, Bodo Niggemann, Norbert Hübner, Heather J. Cordell, Maria Bradley, Young-Ae Lee

OP16 Allergic multimorbidity of asthma, rhinitis and eczema in the first 2 decades of the German MAS birth cohort

Thomas Keil, Hannah Gough, Linus Grabenhenrich, Dirk Schramm, Andreas Reich, John Beschorner, Antje Schuster, Carl-Peter Bauer, Johannes Forster, Fred Zepp, Young-Ae Lee, Renate Bergmann, Karl Bergmann, Ulrich Wahn, Susanne Lau

OP17 Childhood anaphylaxis: a growing concern

Filipe Benito Garcia, Inês Mota, Susana Piedade, Ângela Gaspar, Natacha Santos, Helena Pité, Mário Morais-Almeida

OP18 Indoor exposure to molds and dampness in infancy and its association to persistent atopic dermatitis in school age. Results from the Greek ISAAC II study

Athina Papadopoulou, Despina Mermiri, Elpida Xatziagorou, Ioannis Tsanakas, Stavroula Lampidi, Kostas Priftis

ORAL ABSTRACT SESSION 4: Pediatric rhinitis—immunotherapy (OP19–OP24)

OP19 Associations between residential greenness and childhood allergic rhinitis and aeroallergen sensitisation in seven birth cohorts

Elaine Fuertes, Iana Markevych, Gayan Bowatte, Olena Gruzieva, Ulrike Gehring, Allan Becker, Dietrich Berdel, Michael Brauer, Chris Carlsten, Barbara Hoffmann, Anita Kozyrskyj, Caroline Lodge, Göran Pershagen, Alet Wijga, Heinrich Joachim

OP20 Full symptom control in pediatric patients with allergic rhinitis and asthma: results of a 2-year sublingual allergen immunotherapy study

Zorica Zivkovic, Ivana Djuric-Filipovic, Jasmina Jocić-Stevanovic, Snežana Zivanovic

OP21 Nasal epithelium of different ages of atopic subjects present increased levels of oxidative stress and increased cell cytotoxicity upon rhinovirus infection

Styliani Taka, Dimitra Kokkinou, Aliki Papakonstantinou, Panagiota Stefanopoulou, Anastasia Georgountzou, Paraskevi Maggina, Sofia Stamataki, Vassiliki Papaevanggelou, Evangelos Andreakos, Nikolaos G. Papadopoulos

OP22 Cluster subcutaneous immunotherapy schedule: tolerability profile in children

Monica Piquer Gibert, Montserrat Alvaro Lozano, Jaime Lozano Blasco, Olga Domínguez Sánchez, Rosa Jiménez Feijoo, Marcia Dias da Costa, Mª Teresa Giner Muñoz, Adriana Machinena Spera, Ana Maria Plaza Martín

OP23 Rhinitis as a risk factor for asthma severity in 11-year old children: population-based cohort study

Matea Deliu, Danielle Belgrave, Angela Simpson, Adnan Custovic

OP24 The Global Lung Function Initiative equations in airway obstruction evaluation of asthmatic children

João Gaspar Marques, Pedro Carreiro-Martins, Joana Belo, Sara Serranho, Isabel Peralta, Nuno Neuparth, Paula Leiria-Pinto

POSTER DISCUSSION SESSION 1: Food allergy (PD01–PD05)

PD01 Allergen-specific humoral and cellular responses in children who fail egg oral immunotherapy due to allergic reactions

Marta Vazquez-Ortiz, Mariona Pascal, Ana Maria Plaza, Manel Juan

PD02 FoxP3 epigenetic features in children with cow milk allergy

Lorella Paparo, Rita Nocerino, Rosita Aitoro, Ilaria Langella, Antonio Amoroso, Alessia Amoroso, Carmen Di Scala, Roberto Berni Canani

PD04 Combined milk and egg allergy in early childhood: let them eat cake?

Santanu Maity, Giuseppina Rotiroti, Minal Gandhi

PD05 Introduction of complementary foods in relation to allergy and gut microbiota in farm and non-farm children

Karin Jonsson, Annika Ljung, Bill Hesselmar, Ingegerd Adlerbert, Hilde Brekke, Susanne Johansen, Agnes Wold, Ann-Sofie Sandberg

POSTER DISCUSSION SESSION 2: Asthma and wheeze (PD06–PD16)

PD06 The association between asthma and exhaled nitric oxide is influenced by genetics and sensitisation

Björn Nordlund, Cecilia Lundholm, Villhelmina Ullemar, Marianne van Hage, Anne Örtqvist, Catarina Almqvist

PD09 Prevalence patterns of infant wheeze across Europe

Anna Selby, Kate Grimshaw, Thomas Keil, Linus Grabenhenrich, Michael Clausen, Ruta Dubakiene, Alessandro Fiocchi, Marek Kowalski, Nikos Papadopoulos, Marta Reche, Sigurveig Sigurdardottir, Aline Sprikkleman, Paraskevi Xepapadaki, Clare Mills, Kirsten Beyer, Graham Roberts

PD10 Epidemiologic changes in recurrent wheezing infants

Herberto Jose Chong Neto, Gustavo Falbo Wandalsen, Ana Carolina Dela Bianca, Carolina Aranda, Nelson Augusto Rosário, Dirceu Solé, Javier Mallol, Luis García Marcos

PD13 A single nucleotide polymorphism in the GLCCI1 gene is associated with response to asthma treatment in children

IvanaBanic, Matija Rijavec, Davor Plavec, Peter Korosec, Mirjana Turkalj

PD14 Pollen induced asthma: Could small molecules in pollen exacerbate the protein-mediated allergic response?

Alen Bozicevic, Maria De Mieri, Matthias Hamburger

PD15 A qualitative study to understand how we can empower teenagers to better self-manage their asthma

Simone Holley, Ruth Morris, Frances Mitchell, Rebecca Knibb, Susan Latter, Christina Liossi, Graham Roberts

PD16 Polymorphism of endothelial nitric oxide synthase (eNOS) gene among Egyptian children with bronchial asthma

Mostafa M. M. Hassan

POSTER DISCUSSION SESSION 3: Mechanisms—Epidemiology (PD17–PD21)

PD17 Pregnancy outcomes in relation to development of allergy in a Swedish birth cohort

Malin Barman, Anna Sandin, Agnes Wold, Ann-Sofie Sandberg

PD18 Evolution of the IgE response to house dust mite molecules in childhood

Daniela Posa, Serena Perna, Carl-Peter Bauer, Ute Hoffmann, Johannes Forster, Fred Zepp, Antje Schuster, Ulrich Wahn, Thomas Keil, Susanne Lau, Kuan-Wei Chen, Yvonne Resch, Susanne Vrtala, Rudolf Valenta, Paolo Maria Matricardi

PD19 Antibody recognition of nsLTP-molecules as antigens but not as allergens in the German-MAS birth cohort

Olympia Tsilochristou, Alexander Rohrbach, Antonio Cappella, Stephanie Hofmaier, Laura Hatzler, Carl-Peter Bauer, Ute Hoffmann, Johannes Forster, Fred Zepp, Antje Schuster, RaffaeleD’Amelio, Ulrich Wahn, Thomas Keil, Susanne Lau, Paolo Maria Matricardi

PD20 Early life colonization with Lactobacilli and Staphylococcus aureus oppositely associates with the maturation and activation of FOXP3+ CD4 T-cells

Sophia Björkander, Maria A. Johansson, Gintare Lasaviciute, Eva Sverremark-Ekström

PD21 Genome-wide meta-analysis identifies 7 susceptibility loci involved in the atopic march

Ingo Marenholz, Jorge Esparza-Gordillo, Franz Rüschendorf, Anja Bauerfeind, David P. Strachan, Ben D. Spycher, Hansjörg Baurecht, Patricia Margaritte-Jeannin, Annika Sääf, Marjan Kerkhof, Markus Ege, Svetlana Baltic, Melanie C Matheson, Jin Li, Sven Michel, Wei Q. Ang, Wendy McArdle, Andreas Arnold, Georg Homuth, Florence Demenais, Emmanuelle Bouzigon, Cilla Söderhäll, Göran Pershagen, Johan C. de Jongste, Dirkje S Postma, Charlotte Braun-Fahrländer, Elisabeth Horak, Ludmila M. Ogorodova, Valery P. Puzyrev, Elena Yu Bragina, Thomas J Hudson, Charles Morin, David L Duffy, Guy B Marks, Colin F Robertson, Grant W Montgomery, Bill Musk, Philip J Thompson, Nicholas G. Martin, Alan James, Patrick Sleiman, Elina Toskala, Elke Rodriguez, Regina Fölster-Holst, Andre Franke, Wolfgang Lieb, Christian Gieger, Andrea Heinzmann, Ernst Rietschel, Thomas Keil, Sven Cichon, Markus M Nöthen, Craig E Pennell, Peter D Sly, Carsten O Schmidt, Anja Matanovic, Valentin Schneider, Matthias Heinig, Norbert Hübner, Patrick G. Holt, Susanne Lau, Michael Kabesch, Stefan Weidinger, Hakon Hakonarson, Manuel AR Ferreira, Catherine Laprise, Maxim B. Freidin, Jon Genuneit, Gerard H Koppelman, Erik Melén, Marie-Hélène Dizier, A. John Henderson, Young Ae Lee

POSTER DISCUSSION SESSION 4: Food allergy—Anaphylaxis (PD22–PD26)

PD22 Atopy patch test in food protein induced enterocolitis caused by solid food

Purificacion González-Delgado, Esther Caparrós, Fernando Clemente, Begoña Cueva, Victoria M. Moreno, Jose Luis Carretero, Javier Fernández

PD23 Watermelon allergy: a novel presentation

Kate Swan, George Du Toit

PD24 A pilot study evaluating the usefulness of a guideline template for managing milk allergy in primary care

Mudiyur Gopi, Tim Smith, Edara Ramesh, Arun Sadasivam

PD26 Efficacy and safety of cow’s milk oral immunotherapy protocol

Inês Mota, Filipe Benito Garcia, Susana Piedade, Angela Gaspar, Graça Sampaio, Cristina Arêde, Luís Miguel Borrego, Graça Pires, Cristina Santa-Marta, Mário Morais-Almeida

POSTER DISCUSSION SESSION 5: Prevention and treatment—Allergy (PD27–PD36)

PD27 Allergy-protection by the lactic acid bacterium Lactococcus lactis G121: mode-of-action as revealed in a murine model of experimental allergy

Stephanie Brand, Karina Stein, Holger Heine, Marion Kauth

PD29 The relationship between quality of life and morning salivary cortisol after acute bronchiolitis in infancy

Leif Bjarte Rolfsjord, Egil Bakkeheim, Johan Alm, Håvard Ove Skjerven, Kai-Håkon Carlsen, Jon Olav Hunderi, Teresa Løvold Berents, Petter Mowinckel, Karin C. Lødrup Carlsen

PD30 Randomised trial of the efficacy of MP29-02* compared with fluticasone propionate nasal spray in children aged ≥6 years to <12 years with allergic rhinitis

Ulrich Wahn, Ullrich Munzel, William Berger

PD31 10 mg of oral bilastine in 2 to 11 years old children has similar exposure to the adult therapeutic dose (20 mg)

Ulrich Wahn, Román Valiente, Valvanera Vozmediano, John C. Lukas, Mónica Rodríguez

PD33 Daily symptoms, nocturnal symptoms, activity limitations and reliever therapies during the three steps of IOEASMA programme: a comparison

Sebastiano Guarnaccia, Luigi Vitale, Ada Pluda, Emanuele D’Agata, Denise Colombo, Stefano Felici, Valeria Gretter, Susanna Facchetti, Gaia Pecorelli, Cristina Quecchia

PD34 Sensitisation to an inert aeroallergen in weaning rats and longstanding disease, in a sensitisation-tolerant and easily tolerisable rodent strain

George Guibas, Evangelia Spandou, Spyridon Megremis, Peter West, Nikolaos Papadopoulos

PD35 Bacterial and fungi exposure in school and allergic sensitisation in children

João Cavaleiro Rufo, Joana Madureira, Inês Paciência, Lívia Aguiar, Patrícia Padrão, Mariana Pinto, Luís Delgado, Pedro Moreira, João Paulo Teixeira, Eduardo Oliveira Fernandes, André Moreira

PD36 Comparative study of allergy rhinitis between two populations: children vs. adults

Adriana Izquierdo Dominguez, Antonio Valero, Joaquim Mullol, Alfonso Del Cuvillo, Javier Montoro, Ignacio Jauregui, Joan Bartra, Ignacio Davila, Marta Ferrer, Joaquin Sastre

POSTER VIEWING SESSION 1: Inflammation—Genetics—Immunology—Dermatology (PP01–PP09)

PP01 Immune profile in late pregnancy: immunological markers in atopic asthmaticwomen as risk factors for atopy in the progeny

Catarina Martins, Jorge Lima, Maria José Leandro, Glória Nunes, Jorge Cunha Branco, Hélder Trindade, Luis Miguel Borrego

PP02 The impact of neonatal sepsis on development of allergic diseases

Secil Conkar, Mehtap Kilic, Canan Aygun, Recep Sancak

PP03 Clinical overview of selective IgE deficiency in childhood

Athina Papadopoulou, Eleni Tagalaki, Lambros Banos, Anna Vlachou, Fotini Giannoula, Despina Mermiri

PP04 Inverse relationship between serum 25(ΟΗ) vitamin D3 and total IgE in children and adolescence

Athina Papadopoulou, Stavroula Lampidi, Marina Pavlakou, Maria Kryoni, Kostas Makris

PP05

PP06

PP07 Asthma control questionnaire and specific IgE in children

Snezhina Lazova, Guergana Petrova, Dimitrinka Miteva, Penka Perenovska

PP08 Features of chronic urticaria of adolescents

Aliya Klyucharova, Olesya Skorohodkina

PP09 Cutaneous mastocytosis in children: a clinical analysis of 8 cases in Greece

Dimitra Koumaki, Alkisti Manousaki, Maria Agrapidi, Lida Iatridou, Omima Eruk, Konstantinos Myridakis, Emmanouil Manousakis, Vasiliki Koumaki

POSTER VIEWING SESSION 2: Food allergy—Anaphylaxis (PP10–PP47)

PP10 Prognostic factors in egg allergy

Maria Dimou, Maria Ingemansson, Gunilla Hedlin

PP11 Evaluation of the efficacy of an amino acid-based formula in infants who are intolerant to extensively hydrolysed protein formula

Nitida Pastor, Delphine de Boissieu, Jon Vanderhoof, Nancy Moore, Kaitlin Maditz

PP12 Anaphylaxis and epinephrine auto-injector use: a survey of pediatric trainees

Adeli Mehdi, Shaza Elhassan, Carolin Beck, Ahmed Al-Hammadi

PP13 Anaphylaxis in children: acute management in the Emergency Department

Ioana Maris, Ronan O’Sullivan, Jonathan Hourihane,

PP14 Understanding Cumbrian schools preparedness in managing children at risk of anaphylaxis in order to provide training and support which will create healthy and safe environments for children with allergies

George Raptis, Louise Michaelis

PP15 A new valid and reliable parent and child questionnaire to measure the impact of food protein enterocolitis syndrome on children: the FPIES Quality of Life Questionnaire (FPIESQL), Parent and Child Short Form

Audrey DunnGalvin, Matthew Greenhawt, Carina Venter, Jonathan Hourihane

PP16 An in-depth case study investigation of the experiences of teenagers and young adults in growing up and living with food allergy with emphasis on coping, management and risk, support, and social and self-identity

Evelyn O’Regan, Duncan Cronin, Jonathan Hourihane, Anna O’Reilly, Audrey DunnGalvin

PP17 Cow’s milk protein allergy in Constantine. A retrospective study of 62 cases between 1996 and 2013

Foued Abdelaziz, Dounia Khelifi-Touhami, Nihad Selim, Tahar Khelifi-Touhami

PP18

PP19 Cow’s milk and egg oral immunotherapy in children older than 5 years

Pablo Merida, Ana Mª Plaza, Juan Heber Castellanos, Adrianna Machinena, Montserrat Alvaro Lozano, Jaime Lozano, Olga Dominguez, Monica Piquer, Rosa Jimenez, Mª Teresa Giner

PP20 Professionals’ awareness of management of Cow’s Milk Protein Allergy (CMPA) in North Wales Hospitals

Konstantinos Kakleas, Manohar Joishy, Wendmu Maskele, Huw R. Jenkins

PP21

PP22 Anaphylaxis: the great unknown for teachers. Presentation of a protocol for schools

Mercedes Escarrer, Agustín Madroñero, Maria Teresa Guerra, Juan Carlos Julia, Juan Carlos Cerda, Javier Contreras, Eulalia Tauler, Maria Jesus Vidorreta, Ana Rojo, Silvia Del Valle

PP23 Challenges facing children with food allergies and their parents in out of school activity sectors

Niamh Flynn

PP24 A review of food challenges at a Regional Irish Centre

Gary Foley, Carol Harmon, John Fitzsimons

PP25 The use of epinephrine in infants with anaphylaxis

Krasimira Baynova, Ávila Maria Del Robledo, Labella Marina

PP26

PP27

PP28 Mother’s psychological state predicts the expression of symptoms in food allergic children

Aaron Cortes, Alicia Sciaraffia, Angela Castillo

PP29 The correlation between sIgE towards tree nuts and birch pollen in a Danish Pediatric Allergy Clinic

Nanna Juel-Berg, Kirsten Skamstrup Hansen, Lars Kærgaard Poulsen

PP30 Food allergy in children: evaluation of parents’ use of online social media

Andreia Florina Nita, Ioana Valentina Nenciu, Adina Lazar, Dumitru Oraseanu

PP31 The impact of food allergy on quality of life: FAQLQ questionnaire

Rita Aguiar, Anabela Lopes, Maria J. Paes, Amélia S. Santos, M. A. Pereira-Barbosa

PP32 An unexpected cause of anaphylaxis: potato

Hatice Eke Gungor, Salih Uytun, Umit Murat Sahiner, Yasemin Altuner Torun

PP33 Is it clinical phenotype of allergic diseases determined by sensitisation to food?

Mirjana Zivanovic, Marina Atanasković-Marković

PP34

PP35 Prescribing adrenaline auto-injectors in children in 2014: the data from regional pediatricians

Tina Vesel, Mihaela Nahtigal, Andreja Obermayer-Temlin, Eva Šoster Križnik, Mirjana Maslar, Ruben Bizjak, Marjeta Tomšič-Matic, Sonja Posega-Devetak, Maja Skerbinjek-Kavalar, Mateja Predalič, Tadej Avčin

PP36 Who should have an adrenaline autoinjector? Adherence to the European and French guidelines among 121 allergists from the Allergy Vigilance Network

Guillaume Pouessel, Etienne Beaudouin, Anne M. Moneret-Vautrin, Antoine Deschildre, Allergy Vigilance Network

PP37 Anaphylaxis by Anacardium Occidentale

Marta Viñas, Bartolomé Borja, Nora Hernández, Mª José Castillo, Adriana Izquierdo, Marcel Ibero

PP38 Anaphylaxis with honey in a child

S. Tolga Yavuz, Ali Gungor, Betul Buyuktiryaki, Ozan Koc, Can Naci Kocabas, Faysal Gok

PP39 Evaluation of courses adopted to children on prevention, recognition and management of anaphylaxis

Tina Vesel, Mihaela Nahtigal

PP40 Symptomatic dust mites and shrimp allergy: three pediatric case reports

Filipa Almeida, Susana Lopes, Cristina Madureira, Tânia Lopes, Fernanda Carvalho

PP41 Poor identification rates of nuts by high risk individuals: a call for improved education and support for families

Camille Heming, Emily Garrett, Adam Blackstock, Santanu Maity, Rahul Chodhari

PP42 DAFALL: database of food allergies in the Czech Republic

Simona Belohlavkova, Eliska Kopelentova, Petr Visek, Ivana Setinova, Ivana Svarcova

PP43 Serological cross-reactivity between grass and wheat is not only caused by profilins and CCDs

Sigrid Sjölander, Nora Nilsson, Malin Berthold, Helena Ekoff, Gunilla Hedlin, Magnus Borres, Caroline Nilsson

PP44 Oil body associated proteins in children with nuts allergy. Allergens to consider in IgE-mediated nuts allergy

Loreto González Domínguez, Cristina Muñoz Archidona, Ana Moreira Jorge, Sergio Quevedo Teruel, Teresa Bracamonte Bermejo, Miriam Castillo Fernández, Fernando Pineda de la Losa, Luis Ángel Echeverría Zudaire

PP45

PP46 Protective effect of helicobacter pylori infection against food allergy in children

Olga Vrani, Antigone Mavroudi, Maria Fotoulaki, Maria Emporiadou, Kleomenis Spiroglou, Ioannis Xinias

PP47 Anaphylaxis pathway: A road tryp-tase to success?

Helyeh A. Sadreddini, Mia Warnes, Donna Traves

POSTER VIEWING SESSION 3: Miscellaneous (PP48–PP58)

PP48 Surveillance study on safety of SLIT in pediatric population

Ivana Djuric-Filipovic, Zorica Zivkovic, Snežana Zivanovic, Gordana Kostić, Đorđe Filipovic

PP49 Efficacy and safety of mixed mite subcutaneous immunotherapy among allergic rhinitis patients in the Northeastern Thailand

Sawapon Sittisomwong, Siripong Sittisomwong

PP50 Effect of inhaled beclomethasone or placebo on brain stem activity in a patient chronically treated with steroids: preliminary report

Zygmunt Podolec, Marcin Hartel, Daria Panek, Magdalena Podolec-Rubiś, Tomasz Banasik

PP51 Sensitisation to aeroallergens in patients with allergic rhinitis, asthma and atopic dermatitis in Shiraz, Southwestern Iran

Elham Abbasi, Mozhgan Moghtaderi

PP52 Referring a child for allergy test: how appropriate are we?

Phani Sanneerappa, Alina Deliu, Moosa Kutty, Nagabathula Ramesh

PP53 EBV lymphoproliferative disease and cardiac lymphoma in a STK4 deficient patient

Roya Sherkat, Mohammad Reza Sabri, Bahar Dehghan, Hamid Bigdelian, Nahid Raeesi, Mino Afshar, Hamid Rahimi, Christoph Klein

PP54 A case study: the effect of massive honeybees attack on various body parameters atopic girl including allergy

Mohemid Al-Jebouri

PP55 The role of TLR9, NLRP3 and proIL-1β in activation of antiviral innate immunity

Oxana A. Svitich, Daria O. Zubacheva, Dmitrii A. Potemkin, Ludmila V. Gankovskaya, Vitalii V. Zverev

PP56 Overnight pulse oximetry, as a screening tool to diagnose obstructive sleep apnoea. How effective is it?

Phani Sanneerappa, Elaine OB Doyle, Paul Gallagher, Nagabathula Ramesh

PP57 The presentation and management of acute urticaria and allergic reactions in children in a multi-ethnic, inner city Emergency Department (ED)

Sherine Dewlett, Kin Man, Minal Gandhi, James Pocock, Anna Gerrardhughes

PP58 Food allergens responsible for delayed-type sensitisation in atopy patch test in children diagnosed with autism spectrum disorder

Jolanta Wasilewska, Maciej Kaczmarski, Dariusz Lebensztejn

POSTER VIEWING SESSION 4: Asthma—Rhinitis (PP59–PP87)

PP59 Systematic review of incense as a trigger factor for asthma

Chandramani Thuraisingham, Davendralingam Sinniah

PP60 Increased risks of mood and anxiety disorders in children with asthma

Yue Chen, Xiaomei Mei

PP61

PP62 Asthma Control Test (ACT) and Pediatric Asthma Quality of Life Questionnaire (PAQLQ) association in children

Sebnem Ozdogan, Pinar Karadeniz, Durdugul Ayyildiz-Emecen, Ummuhan Oncul

PP63 Seasonal and gender variations in vitamin D levels in children with asthma and its association with pulmonary function tests

Sebnem Ozdogan, Gizem Sari, Sabanur Cavdar

PP64 Defining treatment response in childhood asthma: rationale and design of the Pharmacogenomics in the Childhood Asthma (PiCA) consortium

Niloufar Farzan, Susanne J. Vijverberg, Colin J. Palmer, Kelan G. Tantisira, Anke-Hilseon Maitland-van der Zee behalf of the PiCA consortium

PP65 Prevalence of asthma and allergic disease in patients with inflammatory disease compared to celiac disease

Fatma Yavuzyilmaz, Sebnem Ozdogan, Nafiye Urganci, Merve Usta

PP66 A severe case with cystic fibrosis (CF) asthma

Mehmet Hoxha, Maksim Basho

PP67 Severe asthma exacerbation complicated with pneumothorax in a child with uncontrolled asthma due to poor treatment compliance

Ioana Valentina Nenciu, Andreia Florina Nita, Adina Lazar, Alexandru Ulmeanu, Carmen Zapucioiu, Dumitru Oraseanu

PP68 Evaluation of the Pediatric Quality of Life inventory (PedsQL) asthma module among low income asthmatic children and adolescents in Sao Paolo, Brazil

Gustavo F. Wandalsen, Fernanda Monteiro, Dirceu Solé

PP69 Early initiation of specific immunotherapy in asthma patients leads to higher benefits

Blerta Lame, Eris Mesonjesi, Arjeta Sherri

PP70 Treatment resistant asthma and rhinosinusitis with recurrent pulmonary infections. Is it primary ciliary dyskinesia?

Alkerta Ibranji, Laert Gjati, Gjustina Loloci, Ardii Bardhi

PP71 The comparison of sensitisation to animal allergens in children- and adult- onset patients with asthma

Behnam Moghtaderi, Shirin Farjadian, Dorna Eghtedari

PP72 Characterisation of children less than five years with wheezing episodes in Cali, Colombia

Manuela Olaya, Laura Del Mar Vasquez, Luis Fernando Ramirez, Carlos Daniel Serrano

PP73 Evaluation of the patients with recurrent croup

Belgin Usta Guc, Suna Asilsoy, Fulya Ozer

PP74 Obesity in adolescence compromising the asthma control

Guergana Petrova, Sylvia Shopova, Vera Papochieva, Snezhina Lazova, Dimitrinka Miteva, Penka Perenovska

PP75 Sleep behavior in children with persistent allergic rhinitis

Gustavo F. Wandalsen, Jessica Loekmanwidjaja, Márcia Mallozi, Dirceu Solé

PP76 Randomised trial of the safety of MP29-02* compared with fluticasone propionate nasal spray in children aged ≥4 years to <12 years with allergic rhinitis

William Berger, Ulrich Wahn, Paul Ratner, Daniel Soteres

PP77 Safety and tolerability evaluation of bilastine 10 mg in children from 2 to 11 years of age with allergic rhinoconjunctivitis or urticaria

Zoltán Novák, Anahí Yáñez, Kiss Ildikó, Piotr Kuna, Miguel Tortajada, Román Valiente, the Bilastine Pediatric Safety Study Group

PP78 Sensitisation to Alternaria alternata: Is it a risk factor for severe rhinitis?

Susana Lopes, Filipa Almeida, Tânia Lopes, Cristina Madureira, José Oliveira, Fernanda Carvalho

PP79 Validation of the Patient Benefit Index (PBI) for the assessment of patient-related outcomes in allergic rhinitis in children

Julia Feuerhahn, Christine Blome, Meike Hadler, Efstrathios Karagiannis, Anna Langenbruch, Matthias Augustin

PP80 Efficacy of sublingual tablet of house dust mite allergen extracts in adolescents with house dust mite-associated allergic rhinitis

Michel Roux, Shinji Kakudo, Efstrathios Karagiannis, Robert K. Zeldin

PP81 Lung function improvement in a child treated with omalizumab for bronchial asthma

Anna Sokolova, Tiago Milheiro Silva

PP82 How to treat a child suffering from asthma, allergic rhinitis, allergy to peanuts and diabetes at the same time?

Snezana S. Zivanovic, Vesna Cvetkovic, Ivana Nikolic, Sonja J. Zivanovic

PP83 Nitric oxide in exhaled air in the relationship of the degree of sensitisation to aeroallergens

Snezana S. Zivanovic, Ljiljana Saranac, Ivana Nikolic, Sonja J. Zivanovic, Zorica Zivkovic

PP84 Clinical basis of diagnostic errors in pediatric asthma

Zoia Nesterenko

PP85

PP86 Childhood asthma control in Serbia and organised Asthma Educational Intervention (AEI)

Snezana Radic, Branislava Milenkovic, Spomenka Smiljanic, Milka Micic-Stanijevic, Olivera Calovic

PP87 Experience from a group of adolescents with severe allergic asthma treated with Omalizumab

Anne Marie Bro Hofbauer, Lone Agertoft

THEMATIC POSTER SESSION 1: Prevention and Treatment—Epidemiology (TP01–TP18)

TP01 A cost effective primary school asthma education program: pilot study from inner London schools

Lucy Everson, Jessica Kearney, Jonny Coppel, Simon Braithwaite, Rahul Chodhari

TP02 The prevalence of allergic diseases among 14–15 years old adolescents in two Danish birth cohorts 14 years apart

Elisabeth S. Christiansen, Henrik Fomsgaard Kjaer, Esben Eller, Charlotte G. Mørtz, Susanne Halken

TP03 Does pattern of sensitisation to phleum pratense change with age? Is it different in children with allergic rhinitis or asthma?

Cristina Román India, Ana Moreira Jorge, Loreto González Domínguez, Cristina Muñoz Archidona, Sergio Quevedo Teruel, Teresa Bracamonte Bermejo, Juana Jiménez Jiménez, Luis Echeverría Zudaire

TP04 Practicalities of prevention of peanut allergy: modelling a national response to LEAP

Cathal O’Connor, Jonathan Hourihane

TP05 Comparison of the influence of sunflower seed oil and skin care lotion on the skin barrier function of newborns: a randomised controlled trial

Varvara Kanti, Lena Lünnemann, Günther Malise, Laine Ludriksone, Andrea Stroux, Wolfgang Henrich, Michael Abu-Dakn, Ulrike Blume-Peytavi, Natalie Garcia Bartels

TP06 The effect of daily skin care on skin barrier properties in infants with dry skin and risk for atopic dermatitis

Varvara Kanti, Lena Lünnemann, Laine Ludriksone, Marianne Schario, Andrea Stroux, Ulrike Blume-Peytavi, Natalie Garcia Bartels

TP07 Change in sum total aeroallergen skin prick test wheal diameters at 6 months predicts which children will respond to subcutaneous immunotherapy by three years

Thorsten Stanley, Nicolien Brandenbarg

TP08 Are mobile apps regarding adrenaline auto-injectors accessed by adolescents for support and education in the community?

Alia Boardman, Gary McGreevy, Emily Rodger, Katherine Knight, Victoria Timms, Trisha Taylor, Gemma Scanlan, Roisin Fitzsimons

TP09

TP10 Prevention of early atopic dermatitis among low-atopy-risk infants by immunoactive prebiotics is not sustained after the first year of life

Grüber Christoph, Ulrich Wahn, Margriet van Stuivenberg, Fabio Mosca, Guido Moro, Gaetano Chirico, Christian P. Braegger, Joseph Riedler, Yalcin Yavuz, Günther Boehm

TP11

TP12

TP13 Treatment with Omalizumab in a 16-year-old Caucasian girl with refractory solar urticaria

Stefania Arasi, Giuseppe Crisafulli, Lucia Caminiti, Federica Porcaro, Giovanni Battista Pajno

TP14 Ultra-pure soft water ameliorates skin conditions of adult and child patients with atopic dermatitis

Akane Tanaka, Yaei Togawa, Kumiko Oida, Naotomo Kambe, Peter Arkwright, Yosuke Amagai, Naoki Shimojo, Yasunori Sato, Hiroyuki Mochizuki, Hyosun Jang, Saori Ishizaka, Hiroshi Matsuda

TP15 Potential adjuvant effect of immunomodulator to improve specific immunotherapy in asthmatic child

Wisnu Barlianto, Ery Olivianto, H. M. S. Chandra Kusuma

TP16 How can Component Resolved Diagnosis (CRD) influence in Specific Immunotherapy (SIT) prescription, in a Spanish children population

Ana Moreira Jorge, Cristina Román India, Loreto González Domínguez, Cristina Muñoz Archidona, Juana Jiménez Jiménez, Teresa Bracamonte Bermejo, Sergio Quevedo Teruel, Luis Echeverría Zudaire

TP17 Mitochondrial dysfunction in food allergy: effects of L. rhamnosus GG in a mice model of peanut allergy

Rosita Aitoro, Mariapia Mollica, Roberto Berni Canani, Giovanna Trinchese, Elena Alfano, Antonio Amoroso, Lorella Paparo, Francesco Amato, Claudio Pirozzi, Antonio Calignano, Rosaria Meli

TP18 Prediction of atopic diseases in childhood: elevated blood eosinophils in infancy in a high risk birth cohort

Siri Rossberg, Kerstin Gerhold, Kurt Zimmermann, Mohammad Zaino, Thomas Geske, Eckard Hamelmann, Susanne Lau

THEMATIC POSTER SESSION 2: Food allergy—Anaphylaxis (TP19–TP38)

TP19

TP20

TP21 Double-blind provocation tests in non-IgE mediated cow’s milk allergy and the occurrence of placebo reactions

Sarah Bogovic, Jochem van den Berg, Chantal Janssen

TP22 Gradual introduction of baked egg (BE) in egg allergic patients under 2 years old

Angela Claver

TP23 Randomised controlled trial of SOTI with raw hen’s egg in children with persistent egg allergy I: safety and efficacy of daily vs. weekly protocols of induction

Mª Flor Martin-Muñoz, C. Martorell, M. T. Belver, E. Alonso Lebrero, L. Zapatero, V. Fuentes, M. Piqué, A. Plaza, C. Muñoz, A. Martorell, Cristina Blasco, B. Villa, C. Gómez, S. Nevot, J. M. García, L. Echeverria

TP24 Randomised controlled trial of SOTI with raw hen’s egg in children with persistent egg allergy II: a randomised controlled trial to study a safer, more effective and easy to perform maintenance (daily vs. every two days) pattern of egg SOTI

Mª Flor Martin-Muñoz, C. Martorell, M. T. Belver, E. Alonso Lebrero, L. Zapatero, V. Fuentes, M. Piqué, A. Plaza, C. Muñoz, A. Martorell, Cristina Blasco, B. Villa, C. Gómez, S. Nevot, J. M. García, L. Echeverria

TP25 Determining the safety of baked egg home reintroduction for children with mild egg allergy

Brenda DeWitt, Judith Holloway, Donald Hodge

TP26 Demographics, investigations and patterns of sensitisation in children with oral allergy syndrome in a London Teaching Hospital

Sian Ludman, Merhdad Jafari-Mamaghani, Rosemary Ebling, Adam T. Fox, Gideon Lack, George Du Toit

TP27 Airborne peanut challenge in children: allergic reactions are rare

Sofia Lovén Björkman, Caroline Nilsson, Natalia Ballardini

TP28 The nutty question on Pediatric Wards: to be or “nut” to be?

Supriyo Basu, Jenny Hallet, Jyothi Srinivas

TP29

TP30

TP31 Allergy education in nursery schools

Hazel Stringer, Nicola Jay

TP32 Food allergy in the first year of life

Tânia Lopes, Cristina Madureira, Filipa Almeida, Susana Lopes, Paula Fonseca, Clara Vieira, Fernanda Carvalho

TP33 Prevalence and geographic distribution of oral allergy syndrome in Italian children: a multicenter study

Carla Mastrorilli, Carlo Caffarelli, Riccardo Asero, Salvatore Tripodi, Arianna Dondi, Gianpaolo Ricci, Carlotta Povesi Dascola, Elisabetta Calamelli, Francesca Cipriani, Andrea Di Rienzo Businco, Annamaria Bianchi, Paolo Candelotti, Tullio Frediani, Carmen Verga, Paolo Maria Matricardi

TP34 Are common standardised allergen extracts used in skin test enough in the diagnosis of nuts allergy?

Cristina Muñoz Archidona, Loreto González Domínguez, Ana Moreira Jorge, Sergio Quevedo Teruel, Teresa Bracamonte Bermejo, Miriam Castillo Fernández, Fernando Pineda de la Losa, Luis Ángel Echeverría Zudaire

TP35 Evaluation of IgE sensitisation in children with allergic proctocolitis and its relationship to atopic dermatitis

Despina Mermiri, Paraskevi Korovessi, Skevi Tiliakou, Evaggelia Tavoulari, Kalliopi-Maria Moraiti, Fotini Giannoula, Athina Papadopoulou

TP36 Food allergy in children: are we managing them appropriately in the Emergency Department?

Wan Jean Tee, Samir Deiratany, Raymond Seedhoo, Roisin McNamara, Ike Okafor

TP37 Importance of oil body associated allergenic proteins in nuts suspected allergy children

Loreto González Domínguez, Ana Moreira Jorge, Cristina Muñoz Archidona, Teresa Bracamonte Bermejo, Sergio Quevedo Teruel, Fernando Pineda de la Losa, Miriam Castillo Fernández, Luis Ángel Echeverría Zudaire

TP38 Practical application of basophil activation test in children with food allergy

Ekaterina Khaleva, Gennady Novic, Natalia Bychkova

THEMATIC POSTER SESSION 3: Asthma (TP39–TP57)

TP39 Effect of corticosteroid therapy upon serum magnesium level in chronic asthmatic children

Amany Abd Al-Aziz, Amany Fatouh, Ayat Motawie, Eman El Bostany, Amr Ibrahim

TP40 ADAM33 in Bulgarian children with asthma

Guergana Petrova, Dimitrinka Miteva, Snezhina Lazova, Penka Perenovska, Sylvia Andonova, Alexey Savov

TP41

TP42 The impact of vitamin D serum levels in asthma and allergic rhinitis

Maria Zoto, Marialena Kyriakakou, Paraskevi Xepapadaki, Nikolaos G. Papadopoulos

TP43 Life-threatening, first reported, paradoxical bronchospasm after nebulised Salbutamol in a 10 year old child

Paraskevi Korovessi, Mariza Vassilopoulou, Athina Balaska, Lambros Banos, Stavroula Kostaridou, Despina Mermiri

TP44

TP45 Asthma symptoms in children with treatment for allergic rhinoconjunctivitis

Jorien Wartna, Arthur M. Bohnen, Gijs Elshout, David H. J. Pols, Patrick J. E. Bindels

Erasmus MC, Rotterdam, The Netherlands

TP46 Atopy increased the risk of developing exercise-induced bronchoconstriction in young athletes

Sven F. Seys; Ellen Dilissen, Sarah Van der Eycken, An-Sofie Schelpe, Gudrun Marijsse, Thierry Troosters, Vincent Vanbelle, Sven Aertgeerts, Jan L. Ceuppens, Lieven J. Dupont, Koen Peers, Dominique M. Bullens

TP47 The effect of higher BMI on risk for asthma and treatment outcome in overweight and obese children

Ivana Banic, Sandra Bulat Lokas, Jelena Zivkovic, Boro Nogalo, Iva Mrkic Kobal, Davor Plavec, Mirjana Turkalj

TP48

TP49

TP50

TP51

TP52 The impact of a multidisciplinary project intended to change the culture of nebulisers towards pressurised metered dose inhalers

Georgeta Oliveira, Katharine Pike, Alda Melo, Tomás Amélia, José Carlos Cidrais Rodrigues, Cristina Serrano, José Manuel Lopes dos Santos, Carla Lopes

TP53

TP54

TP55

TP56 Increased asthma control in patients with severe persistent allergic asthma after 12 month of nightly temperature controlled laminar airflow (TLA)

Eckard Hamelmann, Uwe Schauer, Karl-Christian Bergmann

TP57

THEMATIC POSTER SESSION 4: Drug allergy—Dermatology (TP58–TP77)

TP58 Should we proceed directly to provocation challenges to diagnose drug allergy? Our experience says yes

Luis Moral, Teresa Toral, Nuria Marco, Beléns García Avilés, Mª Jesús Fuentes, Jesús Garde, Cristina Montahud, Javier Perona, Mª José Forniés

TP59 Anaphylaxis to 13-valent pneumococcal vaccine

Esozia Arroabarren, Marta Anda, Maria Luisa Sanz, Maria Teresa Lizaso, Candida Arregui

TP60 Intrapartum antibiotic exposure for treatment of group B streptococcus was not associated with the development of penicillin allergy in children

Sara May, Martha Hartz, Avni Joshi, Miguel A. Park

TP61 Evaluation of suspected drug hypersensitivity reactions in 169 children referred to the General Hospital

Sonja Posega Devetak, Tina Vesel, Anja Koren Jeverica, Tadej Avčin

TP62 Drug provocation testing: experience of a tertiary hospital

Leonor Castro, Carolina Gouveia, Ana Carvalho Marques, Antonio Jorge Cabral

TP63 Perioperative anaphylaxis: a growing concern in pediatric population

Luis Amaral, Fabrícia Carolino, Eunice Castro, Madalena Passos, Josefina R. Cernadas

TP64 Raising awareness of hypersensitivity to non-steroidal anti-inflammatory drugs in the pediatric age

Fabrícia Carolino, Luís Amaral, Eunice Dias de Castro, Josefina R. Cernadas

TP65 Perioperative anaphylaxis in young children: how to confirm the suspicion

Josefina R. Cernadas, Fabrícia Carolino, Luís Amaral, Fernando Pineda, Armanda Gomes

TP66 A case study of a child suspected to be penicillin allergic-digging deeper

Katherine Knight, Roisin Fitzsimons, Helen Brough

TP67 Prevalence, characteristics and risk factors of hypersensitivity reactions to antibiotics in patients with cystic fibrosis

Jobst Röhmel, Carsten Schwarz, Anne Mehl, Philippe Stock, Doris Staab

TP68 Antibiotic drug hypersensitivity in cystic fibrosis: A pilot study using cellular allergy tests for diagnostics

Jobst Röhmel, Carsten Schwarz, Christine Seib, Doris Staab, Philippe Stock

TP69 Oral antibiotics challenges in children

Anita Critchlow, Alyson Barber, Nicola Jay

TP70 Hypersensitivity reaction to vancomycin: a new successful desensitization protocol

Belen Delavalle, Teresa Garriga, Blanca Vilá, Cristina Blasco

TP71

TP72 Clinical phenotypes according to FLG gene loss of function mutations in children with atopic dermatitis

Francesca Cipriani, Annalisa Astolfi, Costanza Di Chiara, Elisabetta Calamelli, Iria Neri, Annalisa Patrizi, Gianpaolo Ricci

TP73

TP74 Urticaria in children: clinical and epidemiological features

Katerina Neskorodova, Asya Kudryavtseva

TP75

TP76 Acute urticaria at the Pediatrics Emergency Department: is it allergy?

Esozia Arroabarren, Jorge Alvarez, Marta Anda, Miriam Palacios, Marta Martinez-Merino, Ibone Vaquero

TP77

Structural and biological characterization of highly purified hepta-acyl lipid A present in the lipopolysaccharide of the Salmonella enterica sv. Minnesota Re deep rough mutant strain R595

One major component of the Salmonella enterica sv. Minnesota Re deep rough mutant (strain R595) lipopolysaccharide is hepta-acyl lipid A (LAhepta). In a recent publication [Tanamoto K-I, Azumi S. Salmonella-type heptaacylated lipid A is inactive and acts as an antagonist of lipopolysaccharide action on human line cells. J Immunol 2000; 164: 3149—3156] the corresponding synthetic hepta-acyl lipid A (compound 516) was reported to be agonistically inactive but to rather suppress pro-inflammatory activation by the endotoxichexa-acyl lipid A (LAhexa, compound 506) and S-form LPS from Escherichia coli in the human macrophage-like cell lines THP-1 and U937. These results, however, were in contrast to previous findings with human mononuclear cells (hMNC) isolated from peripheral blood, in which compound 516 was found to be an agonist, expressing low, but significant,cytokine-inducing activity as compared to LAhexa. We have investigated the structure of natural LA hepta from the S. enterica sv. Minnesota Re deep rough mutant strain (R595) by TLC immunoblot, MALDI-TOF mass spectrometry and NMR spectroscopy. Using these techniques, the structural identity between LAhepta and the synthetic compound 516 was confirmed. In corroboration of previous findings with studies employing compound 516, purified LA hepta was found to induce the production of TNF- , IL-1 and IL-6 in hMNC, thus displaying moderate agonistic activity. Furthermore, we showed that LAhepta agonistically activated nuclear translocation of NF- B in THP-1 cells, thus clearly ruling out the possibility that LAhepta is an antagonist and that its biological activity is influenced by the type of human myeloid cells used for testing endotoxicity(hMNC versus THP-1 cells).

Inhibition of LPS binding on human monocytes by phosphonooxyethyl analogs of lipid A

We investigated the inhibition of LPS binding on human monocytes by synthetic analogs of lipid A. A common characteristic of the analyzed structures is a α-(or β-) phosphonooxyethyl group in position 1 of the GlcN I of the lipid A backbone. Compounds PE-1, PE-2 and PE-3 are analogs of synthetic Escherichia coli lipid A whereas PE-4 represents an analog of tetraacyl precursor Ia (synthetic compound 406). By determining the ability of these preparations to inhibit the binding of FITC-labeled LPS (E. coli 0111:B4) on human monocytes the relationship between their structure and cellular binding affinity was evaluated. The results showed a structure-dependent hierarchy of inhibition capacity. Thus, compound PE-1 inhibited the binding of FITC-LPS only slightly more than PE-2. However, compound PE-3, possessing β-configurated GlcN I, exhibited a drastically decreased inhibition capability. Best inhibition was obtained with compound PE-4. It was furthermore shown by a Lineweaver-Burk plot that the inhibition of LPS binding was due to competition of FITC-LPS and PE-4 for the same binding structure. The synthesis of stable 1-phosphonooxyethyl analogs of precursor Ia with high affinity for LPS receptor structures but lacking cytokine-inducing capacity (like PE-4) may be of relevance for their function as potent antagonists of LPS in therapy of endotoxic shock and sepsis.

Decay-accelerating factor (DAF/CD55) is a functional active element of the LPS receptor complex

Previously, we identified an 80 kDa membrane protein (LMP80) that is capable of binding to LPS and lipid A in the presence of LBP and sCD14. LMP80 could also be detected after immuno-coprecipitation of cell membranes with LPS and lipid A, indicating a physical contact of LMP80 and LPS/lipid A. Further analysis and peptide sequencing revealed that LMP80 is identical to CD55 (decay accelerating factor, DAF), a regulatory molecule of the complement cascade. Transfection of LPS-hyporesponsive Chinese hamster ovary (CHO) cells with human CD55 resulted in the translocation of NF-κB upon stimulation with LPS or lipid A. Our results demonstrate a new functional role of CD55 as a molecule able to mediate LPS-induced activation of cells that may be part of a multimeric LPS receptor complex.

Investigation on the agonistic and antagonistic biological activities of synthetic Chlamydia lipid A and its use in in vitro enzymatic assays

The synthetic 1,4′-bisphosphorylated penta-acyl and tetra-acyl lipid A structures representing the major molecular species of natural chlamydial lipid A were tested for their endotoxic activities as measured by interleukin-8 release from human embryonic kidney (HEK) 293 cells expressing Toll-like receptor (TLR) 2 or TLR4. Both compounds were unable to activate HEK293 cells transiently transfected with TLR2. The penta-acyl lipid A was a weak activator of HEK293 cells expressing TLR4/MD-2/CD14 whereas tetra-acyl lipid A was inactive even at high concentrations. The weak activity of the penta-acyl lipid A could be antagonized by the tetra-acyl derivative of Escherichia coli lipid A (compound 406) or the anti-CD14 monoclonal antibody MEM-18. Both, tetra- and pentaacyl lipid A were unable to antagonize the activity of synthetic E. coli-type lipid A (compound 506) or smooth lipopolysaccharide of Salmonella enterica serovar Friedenau. Tetra- and penta-acyl lipid A served as acceptors for Kdo transferases from E. coli, Chlamydia trachomatis and Chlamydophila psittaci as shown by in vitro assays and detection of the products by thin layer chromatography and immune staining with monoclonal antibody.

Endosomal recognition of Lactococcus lactis G121 and its RNA by dendritic cells is key to its allergy-protective effects

BACKGROUND

Bacterial cowshed isolates are allergy protective in mice; however, the underlying mechanisms are largely unknown. We examined the ability of Lactococcus lactis G121 to prevent allergic inflammatory reactions.

OBJECTIVE

We sought to identify the ligands and pattern recognition receptors through which L lactis G121 confers allergy protection.

METHODS

L lactis G121-induced cytokine release and surface expression of costimulatory molecules by untreated or inhibitor-treated (bafilomycin and cytochalasin D) human monocyte-derived dendritic cells (moDCs), bone marrow-derived mouse dendritic cells (BMDCs), and moDC/naive CD4⁺ T-cell cocultures were analyzed by using ELISA and flow cytometry. The pathology of ovalbumin-induced acute allergic airway inflammation after adoptive transfer of BMDCs was examined by means of microscopy.

RESULTS

L lactis G121-treated murine BMDCs and human moDCs released T_H1-polarizing cytokines and induced T_H1 T cells. Inhibiting phagocytosis and endosomal acidification in BMDCs or moDCs impaired the release of T_H1-polarizing cytokines, costimulatory molecule expression, and T-cell activation on L lactis G121 challenge. In vivo allergy protection mediated by L lactis G121 was dependent on endosomal acidification in dendritic cells (DCs). Toll-like receptor (Tlr) 13^-/- BMDCs showed a weak response to L lactis G121 and were unresponsive to its RNA. The T_H1-polarizing activity of L lactis G121-treated human DCs was blocked by TLR8-specific inhibitors, mediated by L lactis G121 RNA, and synergistically enhanced by activation of nucleotide-binding oligomerization domain-containing protein (NOD) 2.

CONCLUSION

Bacterial RNA is the main driver of L lactis G121-mediated protection against experimentally induced allergy and requires both bacterial uptake by DCs and endosomal acidification. In mice L lactis G121 RNA signals through TLR13; however, the most likely intracellular receptor in human subjects is TLR8.

Interleukin-4 and interferon-γ orchestrate an epithelial polarization in the airways

Interferon-γ (IFN-γ) and interleukin-4 (IL-4) are key effector cytokines for the differentiation of T helper type 1 and 2 (Th1 and Th2) cells. Both cytokines induce fate-decisive transcription factors such as GATA3 and TBX21 that antagonize the polarized development of opposite phenotypes by direct regulation of each other's expression along with many other target genes. Although it is well established that mesenchymal cells directly respond to Th1 and Th2 cytokines, the nature of antagonistic differentiation programs in airway epithelial cells is only partially understood. In this study, primary normal human bronchial epithelial cells (NHBEs) were exposed to IL-4, IFN-γ, or both and genome-wide transcriptome analysis was performed. The study uncovers an antagonistic regulation pattern of IL-4 and IFN-γ in NHBEs, translating the Th1/Th2 antagonism directly in epithelial gene regulation. IL-4- and IFN-γ-induced transcription factor hubs form clusters, present in antagonistically and polarized gene regulation networks. Furthermore, the IL-4-dependent induction of IL-24 observed in rhinitis patients was downregulated by IFN-γ, and therefore IL-24 represents a potential biomarker of allergic inflammation and a Th2 polarized condition of the epithelium.

Allergy protection by cowshed bacteria - recent findings and future prospects

Since the first publication in 1999, numerous epidemiologic studies provided strong evidence that frequent contact to a traditional farm environment in early life protects children from the development of allergic airway diseases. These consistent findings prompted enormous efforts to identify and characterize the potential causative factors and the underlying immunologic mechanisms in experimental studies. The cumulating evidence for the role of the cowshed-associated bacterial flora led to enhanced efforts not only to identify the relevant species but also to examine their specific immunomodulatory capacity, the bacterial components involved, and particularly the cellular and molecular mechanisms of their interaction with the immune system. We review here the methods applied to identify relevant bacterial species, the species which emerged thereof, and the similarities and differences in their mode of action as revealed so far. We further consider the impact of the current knowledge on worthwhile clinical application and reflect on the required next steps to foster the translation of the encouraging scientific progress which has been made in recent years.

Isolation of Enterococcus faecium NM113, Enterococcus faecium NM213 and Lactobacillus casei NM512 as novel probiotics with immunomodulatory properties

Probiotics, defined as living bacteria that are beneficial for human health, mainly function through their immunomodulatory abilities. Hence, these microorganisms have proven successful for treating diseases resulting from immune deregulation. The aim of this study was to find novel candidates to improve on and complement current probiotic treatment strategies. Of 60 lactic acid bacterial strains that were isolated from fecal samples of healthy, full-term, breast-fed infants, three were chosen because of their ability to activate human immune cells. These candidates were then tested with regard to immunomodulatory properties, antimicrobial effects on pathogens, required pharmacological properties and their safety profiles. To identify the immunomodulatory structures of the selected isolates, activation of specific innate immune receptors was studied. The three candidates for probiotic treatment were assigned Enterococcus faecium NM113, Enterococcus faecium NM213 and Lactobacillus casei NM512. Compared with the established allergy-protective strain Lactococcus lactis G121, these isolates induced release of similar amounts of IL-12, a potent inducer of T helper 1 cells. In addition, all three neonatal isolates had antimicrobial activity against pathogens. Analysis of pharmacological suitability showed high tolerance of low pH, bile salts and pancreatic enzymes. In terms of safe application in humans, the isolates were sensitive to three antibiotics (chloramphenicol, tetracycline and erythromycin). In addition, the Enterococcus isolates were free from the four major virulence genes (cylA, agg, efaAfs and ccf). Moreover, the isolates strongly activated Toll-like receptor 2, which suggests lipopeptides as their active immunomodulatory structure. Thus, three novel bacterial strains with great potential as probiotic candidates and promising immunomodulatory properties have here been identified and characterized.

Anti-endotoxic activity and structural basis for human MD-2·TLR4 antagonism of tetraacylated lipid A mimetics based on βGlcN(1↔1)αGlcN scaffold

Interfering with LPS binding by the co-receptor protein myeloid differentiation factor 2 (MD-2) represents a useful approach for down-regulation of MD-2·TLR4-mediated innate immune signaling, which is implicated in the pathogenesis of a variety of human diseases, including sepsis syndrome. The antagonistic activity of a series of novel synthetic tetraacylated bis-phosphorylated glycolipids based on the βGlcN(1↔1)αGlcN scaffold was assessed in human monocytic macrophage-like cell line THP-1, dendritic cells and human epithelial cells. Two compounds were shown to inhibit efficiently the LPS-induced inflammatory signaling by down-regulation of the expression of TNF-α, IL-6, IL-8, IL-10 and IL-12 to background levels. The binding of the tetraacylated by (R)-3-hydroxy-fatty acids (2 × C_12, 2 × C₁₄), 4,4′-bisphosphorylated βGlcN(1↔1)αGlcN-based lipid A mimetic DA193 to human MD-2 was calculated to be 20-fold stronger than that of Escherichia coli lipid A. Potent antagonistic activity was related to a specific molecular shape induced by the β,α(1↔1)-diglucosamine backbone. ‘Co-planar’ relative arrangement of the GlcN rings was inflicted by the double exo-anomeric conformation around both glycosidic torsions in the rigid β,α(1↔1) linkage, which was ascertained using NOESY NMR experiments and confirmed by molecular dynamics simulation. In contrast to the native lipid A ligands, the binding affinity of βGlcN(1↔1)αGlcN-based lipid A mimetics to human MD-2 was independent on the orientation of the diglucosamine backbone of the synthetic antagonist within the binding pocket of hMD-2 (rotation by 180°) allowing for two equally efficient binding modes as shown by molecular dynamics simulation.

The intestinal archaea Methanosphaera stadtmanae and Methanobrevibacter smithii activate human dendritic cells

The methanoarchaea Methanosphaera stadtmanae and Methanobrevibacter smithii are known to be part of the indigenous human gut microbiota. Although the immunomodulatory effects of bacterial gut commensals have been studied extensively in the last decade, the impact of methanoarchaea in human's health and disease was rarely examined. Consequently, we studied and report here on the effects of M. stadtmanae and M. smithii on human immune cells. Whereas exposure to M. stadtmanae leads to substantial release of proinflammatory cytokines in monocyte-derived dendritic cells (moDCs), only weak activation was detected after incubation with M. smithii. Phagocytosis of M. stadtmanae by moDCs was demonstrated by confocal microscopy as well as transmission electronic microscopy (TEM) and shown to be crucial for cellular activation by using specific inhibitors. Both strains, albeit to different extents, initiate a maturation program in moDCs as revealed by up-regulation of the cell-surface receptors CD86 and CD197 suggesting additional activation of adaptive immune responses. Furthermore, M. stadtmanae and M. smithii were capable to alter the gene expression of antimicrobial peptides in moDCs to different extents.

Taken together, our findings strongly argue that the archaeal gut inhabitants M. stadtmanae and M. smithii are specifically recognized by the human innate immune system. Moreover, both strains are capable of inducing an inflammatory cytokine response to different extents arguing that they might have diverse immunomodulatory functions. In conclusion, we propose that the impact of intestinal methanoarchaea on pathological conditions involving the gut microbiota has been underestimated until now.

Farm-derived Gram-positive bacterium Staphylococcus sciuri W620 prevents asthma phenotype in HDM- and OVA-exposed mice

BACKGROUND

Farm-derived dust samples have been screened for bacteria with potential allergo-protective properties. Among those was Staphylococcus sciuri W620 (S. sciuri W620), which we tested with regard to its protective capacities in murine models of allergic airway inflammation.

METHODS

We employed two protocols of acute airway inflammation in mice administering either ovalbumin (OVA) or house dust mite extract (HDM) for sensitization. Mechanistic studies on the activation of innate immune responses to S. sciuri W620 were carried out using human primary monocytic dendritic cells (moDC) and co-culture with autologous T cells.

RESULTS

The allergo-protective properties of S. sciuri W620 were proven in a T(H)2-driven OVA model as well as in a mixed T(H)1/T(H)2 phenotype HDM model as demonstrated by abrogation of eosinophils and neutrophils in the airways after intranasal treatment. In the HDM model, lymph node cell T(H)1/T(H)2 signature cytokines were decreased in parallel. Studies on human moDC revealed an activation of TLR2 and NOD2 receptors and initiation of DC maturation following incubation with S. sciuri W620. Cytokine expression analyses after exposure to S. sciuri W620 showed a lack of IL-12 production in moDC due to missing transcription of the IL-12p35 mRNA. However, such DC selectively supported T(H)1 cytokine release by co-cultured T cells.

CONCLUSION AND CLINICAL RELEVANCE

Our proof-of-concept experiments verify the screening system of farm-derived dust samples as suitable to elucidate new candidates for allergo-protection. S. sciuri W620 was shown to possess preventive properties on airway inflammation providing the basis for further mechanistic studies and potential clinical implication.

The structure of the extracellular teichoic acids from the allergy-protective bacterium Lactococcus lactis G121

The Gram-positive bacterium Lactococcus lactis G121 is a farm isolate that protects mice from ovalbumin-induced asthma. To understand the molecular mechanisms of such allergy-protective properties, the isolation and characterization of cell envelope constituents is crucial. Here, structural analyses of the extracellular teichoic acid (EC TA) from L. lactis G121 are presented. Extraction with 0.9% saline afforded a crude TA fraction. Consecutive size exclusion chromatography on Biogel P60 and P10 matrix was performed to purify the sample. Chemical component analyses, high-resolution electrospray ionization Fourier-transformed ion cyclotron mass spectrometry, and nuclear magnetic resonance spectroscopy were conducted for structural elucidation. The EC TA was a poly(glycosylglycerol phosphate) molecule with a repeating unit of -6)-[β-D-Glcp-(1→3)-][α-D-GlcpNAc-(1→4)-]α-D-GalpNAc-(1→3)-β-D-GlcpNAc-(1→2)-glycerol-(1-P-).

Histone deacetylase (HDAC) 1 controls the expression of beta defensin 1 in human lung epithelial cells

Deregulation of the expression human beta defensin 1 (DEFB1), an antimicrobial peptide, has been implicated in the pathogenesis of COPD and asthma. Since the molecular mechanisms that regulate DEFB1 gene expression are widely unknown, the epigenetic processes involved in the regulation of the constitutive expression of DEFB1 in lung epithelial cells (A549) were investigated. The data demonstrate that histone deacetylases (HDACs) participate in the regulation of DEFB1 gene expression. Inhibition of the class I HDACs, HDACs 1-3, increases DEFB1 gene expression in A549 cells. Chromatin immunoprecipitation (ChIP) assays revealed that the inhibition of the class I HDACs also results in modifications of the chromatin at the DEFB1 promoter. Histone modifications, histone H3 acetylation and H3K4 trimethylation, that are associated with transcriptional activation, were found to increase after inhibition of HDACs 1-3. Finally, RNAi knockdown experiments identified HDAC1 as the sole HDAC responsible for maintaining the constitutive level of DEFB1 transcription. Taken together, our data reveal epigenetic mechanisms which are the basis of the maintenance of the constitutive gene expression of human beta defensin 1.

LPS-induced cytokine production in human monocytes and macrophages

Lipopolysaccharide (LPS) from Gram-negative bacteria is one of the most potent innate immune-activating stimuli known. Here we review the current understanding of LPS effects on human monocyte and macrophage function. We provide an overview of LPS signal transduction with attention given to receptor cooperativity and species differences in LPS responses, as well as the role of tyrosine phosphorylation and lysine acetylation in signalling. We also review LPS-regulated transcription, with emphasis on chromatin remodeling and primary versus secondary transcriptional control mechanisms. Finally, we review the regulation and function of LPS-inducible cytokines produced by human monocytes and macrophages including TNFα, the IL-1 family, IL-6, IL-8, the IL-10 family, the IL-12 family, IL-15 and TGFβ.

Immunization with an anti-idiotypic antibody against the broadly lipopolysaccharide-reactive antibody WN1 222-5 induces Escherichia coli R3-core-type specific antibodies in rabbits

The mouse monoclonal antibody (mAb) WN1 222-5 recognizes a carbohydrate epitope in the inner core region of LPS that is shared by all strains of Escherichia coli and Salmonella enterica and is able to neutralize their endotoxic activity in vitro and in vivo. Immunization of mice with mAb WN1 222-5 yielded several anti-idiotypic mAbs one of which (mAb S81-19) competitively inhibited binding of mAb WN1 222-5 to E. coli and Salmonella LPS. After immunization of rabbits with mAb S81-19, the serological responses towards LPS were characterized at intervals over two years. Whereas the serological response against the anti-idiotype developed as expected, the anti-anti-idiotypic response against LPS developed slowly and antibodies appeared after 200 d that bound to E. coli LPS of the R3 core-type and neutralized its TNF-α inducing capacity for human peripheral mononuclear cells. We describe the generation of a novel anti-idiotypic antibody that can induce LPS core-reactive antibodies upon immunization in rabbits and show that it is possible, in principle, to obtain LPS neutralizing antibodies by anti-idiotypic immunization against the mAb WN1 222-5. The mimicked epitope likely shares common determinants with the WN1 222-5 epitope, yet differences with respect to either affinity or specificity do exist, as binding to smaller oligosaccharides of the inner core was not observed.

Increased expression of beta-defensin 1 (DEFB1) in chronic obstructive pulmonary disease

On-going airway inflammation is characteristic for the pathophysiology of chronic obstructive pulmonary disease (COPD). However, the key factors determining the decrease in lung function, an important clinical parameter of COPD, are not clear. Genome-wide linkage analyses provide evidence for significant linkage to airway obstruction susceptibility loci on chromosome 8p23, the location of the human defensin gene cluster. Moreover, a genetic variation in the defensin beta 1 (DEFB1) gene was found to be associated with COPD. Therefore, we hypothesized that DEFB1 is differently regulated and expressed in human lungs during COPD progression. Gene expression of DEFB1 was assessed in bronchial epithelium and BAL fluid cells of healthy controls and patients with COPD and using bisulfite sequencing and ChIP analysis, the epigenetic control of DEFB1 mRNA expression was investigated. We can demonstrate that DEFB1 mRNA expression was significantly increased in bronchopulmonary specimen of patients with COPD (n = 34) vs. healthy controls (n = 10) (p<0.0001). Furthermore, a significant correlation could be detected between DEFB1 and functional parameters such as FEV₁ (p = 0.0024) and the FEV₁/VC ratio (p = 0.0005). Upregulation of DEFB1 mRNA was paralleled by changes in HDAC1-3, HDAC5 and HDAC8 mRNA expression. Whereas bisulfite sequencing revealed no differences in the methylation state of DEFB1 promoter between patients with COPD and controls, ChIP analysis showed that enhanced DEFB1 mRNA expression was associated with the establishment of an active histone code. Thus, expression of human DEFB1 is upregulated and related to the decrease in pulmonary function in patients with COPD.