The impact of high-IgE levels on metabolome and microbiome in experimental allergic enteritis.

BACKGROUND: The pathological mechanism of the gastrointestinal forms of food allergies is less understood in comparison to other clinical phenotypes, such as asthma and anaphylaxis Importantly, high-IgE levels are a poor prognostic factor in gastrointestinal allergies. METHODS: This study investigated how high-IgE levels influence the development of intestinal inflammation and the metabolome in allergic enteritis (AE), using IgE knock-in (IgEki) mice expressing high levels of IgE. In addition, correlation of the altered metabolome with gut microbiome was analysed. RESULTS: Ovalbumin-sensitized and egg-white diet-fed (OVA/EW) BALB/c WT mice developed moderate AE, whereas OVA/EW IgEki mice induced more aggravated intestinal inflammation with enhanced eosinophil accumulation. Untargeted metabolomics detected the increased levels of N-tau-methylhistamine and 2,3-butanediol, and reduced levels of butyric acid in faeces and/or sera of OVA/EW IgEki mice, which was accompanied with reduced Clostridium and increased Lactobacillus at the genus level. Non-sensitized and egg-white diet-fed (NC/EW) WT mice did not exhibit any signs of AE, whereas NC/EW IgEki mice developed marginal degrees of AE. Compared to NC/EW WT mice, enhanced levels of lysophospholipids, sphinganine and sphingosine were detected in serum and faecal samples of NC/EW IgEki mice. In addition, several associations of altered metabolome with gut microbiome-for example Akkermansia with lysophosphatidylserine-were detected. CONCLUSIONS: Our results suggest that high-IgE levels alter intestinal and systemic levels of endogenous and microbiota-associated metabolites in experimental AE. This study contributes to deepening the knowledge of molecular mechanisms for the development of AE and provides clues to advance diagnostic and therapeutic strategies of allergic diseases.

Effects of pectin methyl-esterification on intestinal microbiota and its immunomodulatory properties in naive mice.

Pectins are dietary fibers that are attributed with several beneficial immunomodulatory effects. Depending on the degree of esterification (DE), pectins can be classified as high methoxyl pectin (HMP) or low methoxyl pectin (LMP). The aim of this study was to investigate the effects of pectin methyl-esterification on intestinal microbiota and its immunomodulatory properties in naive mice. Supplementation of the diet with LMP or HMP induced changes in the composition of the intestinal microbiota in mice toward Bacteroides, which was mainly promoted by HMP. Metabolome analysis of stool samples from pectin-fed mice showed a different effect of the two types of pectin on the levels of short-chain fatty acids and bile acids, which was consistent with highly efficient in vivo fermentation of LMP. Analysis of serum antibody levels showed a significant increase in IgG and IgA levels by both pectins, while FACS analysis revealed a decrease of infiltrating inflammatory cells in the intestinal lamina propria by HMP. Our study revealed that the structural properties of the investigated pectins determine fermentability, effects on microbial composition, metabolite production, and modulation of immune responses. Consumption of HMP preferentially altered the gut microbiota and suppressed pro-inflammatory immune responses, suggesting a beneficial role in inflammatory diseases.

Non-IgE-Mediated Gastrointestinal Food Protein-Induced Allergic Disorders. Clinical Perspectives and Analytical Approaches.

Non-IgE-mediated gastrointestinal food allergy (non-IgE-GI-FA) is the name given to a series of pathologies whose main entities are food protein-induced allergic proctocolitis (FPIAP), food protein-induced enteropathy (FPE), and food protein-induced enterocolitis syndrome (FPIES). These are more uncommon than IgE-mediated food allergies, their mechanisms remain largely unknown, and their diagnosis is mainly done by clinical history, due to the lack of specific biomarkers. In this review, we present the latest advances found in the literature about clinical aspects, the current diagnosis, and treatment options of non-IgE-GI-FAs. We discuss the use of animal models, the analysis of gut microbiota, omics techniques, and fecal proteins with a focus on understanding the pathophysiological mechanisms of these pathologies and obtaining possible diagnostic and/or prognostic biomarkers. Finally, we discuss the unmet needs that researchers should tackle to advance in the knowledge of these barely explored pathologies.

The Dietary Fiber Pectin: Health Benefits and Potential for the Treatment of Allergies by Modulation of Gut Microbiota.

PURPOSE OF REVIEW: The incidence of allergies is increasing and has been associated with several environmental factors including westernized diets. Changes in environment and nutrition can result in dysbiosis of the skin, gut, and lung microbiota altering the production of microbial metabolites, which may in turn generate epigenetic modifications. The present review addresses studies on pectin-mediated effects on allergies, including the immune modulating mechanisms by bacterial metabolites. RECENT FINDINGS: Recently, microbiota have gained attention as target for allergy intervention, especially with prebiotics, that are able to stimulate the growth and activity of certain microorganisms. Dietary fibers, which cannot be digested in the gastrointestinal tract, can alter the gut microbiota and lead to increased local and systemic concentrations of gut microbiota-derived short chain fatty acids (SCFAs). These can promote the generation of peripheral regulatory T cells (Treg) by epigenetic modulation and suppress the inflammatory function of dendritic cells (DCs) by transcriptional modulation. The dietary fiber pectin (a plant-derived polysaccharide commonly used as gelling agent and dietary supplement) can alter the ratio of Firmicutes to Bacteroidetes in gut and lung microbiota, increasing the concentrations of SCFAs in feces and sera, and reducing the development of airway inflammation by suppressing DC function. Pectin has shown immunomodulatory effects on allergies, although the underlying mechanisms still need to be elucidated. It has been suggested that the different types of pectin may exert direct and/or indirect immunomodulatory effects through different mechanisms. However, little is known about the relation of certain pectin structures to allergies.

Knowledge, Attitudes, and Risk Perception Toward Avian Influenza Virus Exposure Among Cuban Hunters.

A critical step for decreasing zoonotic disease threats is to have a good understanding of the associated risks. Hunters frequently handle potentially infected birds, so they are more at risk of being exposed to zoonotic avian pathogens, including avian influenza viruses (AIVs). The objective of the current study was to gain a better understanding of Cuban hunters' general hunting practices, focusing on their knowledge and risk perception on avian influenza. An anonymous and voluntary semi-structured questionnaire was designed and applied to 398 hunters. Multiple correspondence analyses found relationships with potential exposure of AIVs to people and domestic animals. The main associated risks factors identified were not taking the annual flu vaccine (60.1%) and not cleaning hunting knives (26.3%); Direct contact with water (32.1%), cleaning wild birds at home (33.2%); receiving assistance during bird cleaning (41.9%), keeping poultry at home (56.5%) and feeding domestic animals with wild bird leftovers (30.3%) were also identified as significant risk factors. The lack of use of some protective measures reported by hunters had no relationship with their awareness on avian influenza, which may imply a lack of such knowledge. The results evidenced that more effective risk communication strategies about the consequences of AIVs infecting human or other animals, and the importance of reducing such risks, are urgently needed.

Human monocyte-derived type 1 and 2 macrophages recognize Ara h 1, a major peanut allergen, by different mechanisms.

Evidence has suggested that major peanut allergen Ara h 1 activates dendritic cells (DCs) via interaction with DC-SIGN (dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin), a C-type lectin receptor, and contributes to development of peanut allergy. Since macrophages, as well as DCs, play a crucial role in innate immunity, we investigated whether natural Ara h 1 (nAra h 1) activates two different subsets of macrophages, human monocyte derived macrophage type 1 (hMDM1: pro-inflammatory model) and type 2 (hMDM2: anti-inflammatory model). hMDM1 and hMDM2 predominantly produced pro-inflammatory cytokines (IL-6 and TNF-α) and an anti-inflammatory cytokine (IL-10) in response to nAra h 1, respectively. hMDM2 took up nAra h 1 and expressed DC-SIGN at higher levels than hMDM1. However, small interfering RNA knockdown of DC-SIGN did not suppress nAra h 1 uptake and nAra h 1-mediated cytokine production in hMDM2. Inhibitors of scavenger receptor class A type I (SR-AI) suppressed the response of hMDM2, but not of hMDM1, suggesting that SR-AI is a major receptor in hMDM2 for nAra h 1 recognition and internalization. nAra h 1 appears to exert stimulatory capacity on DC and macrophages via different receptors. This study advances our understanding how a major peanut allergen interacts with innate immunity.

Does the Food Ingredient Pectin Provide a Risk for Patients Allergic to Non-Specific Lipid-Transfer Proteins?

Pectin, a dietary fiber, is a polysaccharide that is widely used in food industry as a gelling agent. In addition, prebiotic and beneficial immunomodulatory effects of pectin have been demonstrated, leading to increased importance as food supplement. However, as cases of anaphylactic reactions after consumption of pectin-supplemented foods have been reported, the present study aims to evaluate the allergy risk of pectin. This is of particular importance since most of the pectin used in the food industry is extracted from citrus or apple pomace. Both contain several allergens such as non-specific lipid transfer proteins (nsLTPs), known to induce severe allergic reactions, which could impair the use of pectins in nsLTP allergic patients. Therefore, the present study for the first time was performed to analyze residual nsLTP content in two commercial pectins using different detection methods. Results showed the analytical sensitivity was diminished by the pectin structure. Finally, spiking of pectin with allergenic peach nsLTP Pru p 3 led to the conclusion that the potential residual allergen content in both pectins is below the threshold to induce anaphylactic reactions in nsLTP-allergic patients. This data suggests that consumption of the investigated commercial pectin products provides no risk for inducing severe reactions in nsLTP-allergic patients.

Mimicking Antigen-Driven Asthma in Rodent Models-How Close Can We Get?

Asthma is a heterogeneous disease with increasing prevalence worldwide characterized by chronic airway inflammation, increased mucus secretion and bronchial hyperresponsiveness. The phenotypic heterogeneity among asthmatic patients is accompanied by different endotypes, mainly Type 2 or non-Type 2. To investigate the pathomechanism of this complex disease many animal models have been developed, each trying to mimic specific aspects of the human disease. Rodents have classically been employed in animal models of asthma. The present review provides an overview of currently used Type 2 vs. non-Type 2 rodent asthma models, both acute and chronic. It further assesses the methods used to simulate disease development and exacerbations as well as to quantify allergic airway inflammation, including lung physiologic, cellular and molecular immunologic responses. Furthermore, the employment of genetically modified animals, which provide an in-depth understanding of the role of a variety of molecules, signaling pathways and receptors implicated in the development of this disease as well as humanized models of allergic inflammation, which have been recently developed to overcome differences between the rodent and human immune systems, are discussed. Nevertheless, differences between mice and humans should be carefully considered and limits of extrapolation should be wisely taken into account when translating experimental results into clinical use.

CCR8 leads to eosinophil migration and regulates neutrophil migration in murine allergic enteritis.

Allergic enteritis (AE) is a gastrointestinal form of food allergy. This study aimed to elucidate cellular and molecular mechanisms of AE using a murine model. To induce AE, BALB/c wild type (WT) mice received intraperitoneal sensitization with ovalbumin (an egg white allergen) plus ALUM and feeding an egg white (EW) diet. Microarray analysis showed enhanced gene expression of CC chemokine receptor (CCR) 8 and its ligand, chemokine CC motif ligand (CCL) 1 in the inflamed jejunum. Histological and FACS analysis showed that CCR8 knock out (KO) mice exhibited slightly less inflammatory features, reduced eosinophil accumulation but accelerated neutrophil accumulation in the jejunums, when compared to WT mice. The concentrations of an eosinophil chemoattractant CCL11 (eotaxin-1), but not of IL-5, were reduced in intestinal homogenates of CCR8KO mice, suggesting an indirect involvement of CCR8 in eosinophil accumulation in AE sites by inducing CCL11 expression. The potential of CCR8 antagonists to treat allergic asthma has been discussed. However, our results suggest that CCR8 blockade may promote neutrophil accumulation in the inflamed intestinal tissues, and not be a suitable therapeutic target for AE, despite the potential to reduce eosinophil accumulation. This study advances our knowledge to establish effective anti-inflammatory strategies in AE treatment.

Adjuvant Allergen Fusion Proteins as Novel Tools for the Treatment of Type I Allergies.

While acute allergic symptoms can be managed by emergency medication, to date, allergen-specific immunotherapy (SIT) with allergen extracts is the only available curative treatment option. However, the risk of anaphylactic reactions, long treatment duration, varying extract quality, and underrepresentation of certain allergens currently prevent many patients from successfully undergoing SIT. Novel strategies are needed to enhance efficacy, safety, and convenience of allergy treatment. Fusion proteins combining allergen and adjuvant into a single molecule can efficiently induce immune responses by targeting the allergen to the relevant immune cells in vivo. Simultaneous co-delivery of both antigen and adjuvant to the same cell in a fixed molecular ratio triggers the uptake and presentation of the conjugated allergen in the context of the adjuvant-induced immune cell activation. This review summarizes the published strategies to improve the treatment of type I allergies using fusion proteins consisting of allergen (peptides) and either (1) immune-activating bacterial (flagellin, MPLA, S-layer, cholera-, and tetanus toxin), (2) viral (PreS, VP-1, TAT), or (3) fungal (FIP-fve) components, (4) immune-activating DNA motifs, (5) forced delivery of allergens to the MHC-II loading pathway, and (6) killing of immune cells expressing allergen-specific IgE by fusion of the allergen to diphtheria toxin.

Enhanced Open-Circuit Voltage in Perovskite Solar Cells with Open-Cage [60]Fullerene Derivatives as Electron-Transporting Materials.

The synthesis, characterization, and incorporation of open-cage [60]fullerene derivatives as electron-transporting materials (ETMs) in perovskite solar cells (PSCs) with an inverted planar (p-i-n) structure is reported. Following optical and electrochemical characterization of the open-cage fullerenes 2a-c, p-i-n PSCs with a indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS)/perovskite/fullerene/Ag structure were prepared. The devices obtained from 2a-b exhibit competitive power conversion efficiencies (PCEs) and improved open-circuit voltage (Voc) values (>1.0 V) in comparison to a reference cell based on phenyl-C61-butyric-acid methyl-ester (PC61BM). These results are rationalized in terms of a) the higher passivation ability of the open-cage fullerenes with respect to the other fullerenes, and b) a good overlap between the highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO/LUMO) levels of 2a-b and the conduction band of the perovskite.

The vaccine adjuvant MPLA activates glycolytic metabolism in mouse mDC by a JNK-dependent activation of mTOR-signaling.

INTRODUCTION: The detoxified TLR4-ligand MPLA is a successfully used adjuvant in clinically approved vaccines. However, its capacity to activate glycolytic metabolism in mDC and the influence of MPLA-induced metabolic changes on cytokine secretion are unknown. AIM: To analyze the capacity of MPLA to activate mDC metabolism and the mechanisms contributing to MPLA-induced metabolism activation and cytokine secretion. METHODS: C57BL/6 bone-marrow-derived myeloid dendritic cells (mDCs) were stimulated with LPS or MPLA and analyzed for intracellular signaling, cytokine secretion, and metabolic state. mDC were pre-treated with rapamycin (mTOR-inhibitor), U0126, SP600125, SB202190 (MAPK kinase inhibitors), as well as dexamethasone (MAPK- and NFκB-inhibitor) and analyzed for MPLA-induced cytokine secretion and cell metabolic state. RESULTS: Stimulation of mDCs with either LPS or MPLA resulted in a pronounced, mTOR-dependent activation of glucose metabolism characterized by induction of the Warburg Effect, increased glucose consumption from the culture medium, as well as release of LDH. Compared to LPS, MPLA induced significantly lower cytokine secretion. The activation of mDC metabolism was comparable between LPS- and MPLA-stimulated mDCs. The MPLA-induced cytokine secretion could be partially inhibited using mTOR-, MAP kinase-, and NFκB-inhibitors, whereas the activation of glucose metabolism was shown to depend on both mTOR- and JNK-signaling. SUMMARY: The MPLA-induced activation of glycolytic metabolism in mouse mDC was shown to depend on a JNK-mediated activation of mTOR-signaling, while both MAPK- and NFB-signaling contributed to pro-inflammatory cytokine secretion. Understanding the mechanisms by which MPLA activates dendritic cells will both improve our understanding of its adjuvant properties and contribute to the future development and safe application of this promising adjuvant.

Correction: A new family of fullerene derivatives: fullerene-curcumin conjugates for biological and photovoltaic applications.

[This corrects the article DOI: 10.1039/C8RA08334G.].

A new family of fullerene derivatives: Fullerene-curcumin conjugates for biological and photovoltaic applications.

The synthesis and characterization of a family of [60]fullerocurcuminoids obtained via Bingel reactions is reported. The new C60 derivatives include curcumin and curcuminoids with a variety of end groups. Preliminary biological experiments show the potential activity of the compound containing a curcumin addend, which exhibits moderate anti-HIV-1 and radical scavenger properties, but no anti-cancer activity. In addition, the new fullerocurcuminoids exhibit HOMO/LUMO energy levels that are reasonably matched with those of perovskites and when they were tested in perovskite solar cells (PSCs) as the electron transporting material (ETM), photoconversion efficiencies ranging from 14.04%-14.95% were obtained, whereas a value of 16.23% was obtained for [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) based devices.

RAB2A controls MT1-MMP endocytic and E-cadherin polarized Golgi trafficking to promote invasive breast cancer programs.

The mechanisms of tumor cell dissemination and the contribution of membrane trafficking in this process are poorly understood. Through a functional siRNA screening of human RAB GTPases, we found that RAB2A, a protein essential for ER-to-Golgi transport, is critical in promoting proteolytic activity and 3D invasiveness of breast cancer (BC) cell lines. Remarkably, RAB2A is amplified and elevated in human BC and is a powerful and independent predictor of disease recurrence in BC patients. Mechanistically, RAB2A acts at two independent trafficking steps. Firstly, by interacting with VPS39, a key component of the late endosomal HOPS complex, it controls post-endocytic trafficking of membrane-bound MT1-MMP, an essential metalloprotease for matrix remodeling and invasion. Secondly, it further regulates Golgi transport of E-cadherin, ultimately controlling junctional stability, cell compaction, and tumor invasiveness. Thus, RAB2A is a novel trafficking determinant essential for regulation of a mesenchymal invasive program of BC dissemination.

Resolving bundled microtubules using anti-tubulin nanobodies.

Microtubules are hollow biopolymers of 25-nm diameter and are key constituents of the cytoskeleton. In neurons, microtubules are organized differently between axons and dendrites, but their precise organization in different compartments is not completely understood. Super-resolution microscopy techniques can detect specific structures at an increased resolution, but the narrow spacing between neuronal microtubules poses challenges because most existing labelling strategies increase the effective microtubule diameter by 20-40 nm and will thereby blend neighbouring microtubules into one structure. Here we develop single-chain antibody fragments (nanobodies) against tubulin to achieve super-resolution imaging of microtubules with a decreased apparent diameter. To test the resolving power of these novel probes, we generate microtubule bundles with a known spacing of 50-70 nm and successfully resolve individual microtubules. Individual bundled microtubules can also be resolved in different mammalian cells, including hippocampal neurons, allowing novel insights into fundamental mechanisms of microtubule organization in cell- and neurobiology.

A randomized controlled trial of a cognitive rehabilitation intervention for persons with multiple sclerosis.

OBJECTIVE: To explore the feasibility and effects of a computer-assisted cognitive rehabilitation intervention - Memory, Attention, and Problem Solving Skills for Persons with Multiple Sclerosis (MAPSS-MS) - for persons with multiple sclerosis on cognitive performance, memory strategy use, self-efficacy for control of symptoms and neuropsychological competence in activities of daily living (ADL). DESIGN: A randomized controlled single-blinded trial with treatment and wait list control groups. SETTING: Southwestern United States. SUBJECTS: Convenience sample of 61 persons (34 treatment, 27 wait list control) with multiple sclerosis (mean age 47.9 years, SD 8.8). INTERVENTION: The eight-week MAPSS-MS intervention program included two components: (a) eight weekly group sessions focused on building efficacy for use of cognitive compensatory strategies and (b) a computer-assisted cognitive rehabilitation program with home-based training. OUTCOME MEASURES: A neuropsychological battery of performance tests comprising the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) and self-report instruments (use of memory strategies, self-efficacy for control of multiple sclerosis and neuropsychological competence in ADL) were completed at baseline, two months (after classes), and at five months. RESULTS: Both groups improved significantly (P < 0.05) over time on most measures in the MACFIMS battery as well as the measures of strategy use and neuropsychological competence in ADL. There was a significant group-by-time interaction for scores on the measures of verbal memory and the use of compensatory strategies. CONCLUSIONS: The MAPSS-MS intervention was feasible and well-accepted by participants. Given the large relative increase in use of compensatory strategies by the intervention group, it holds promise for enhancing cognitive function in persons with multiple sclerosis.

Home-Based Computer-Assisted Cognitive Training: Feasibility and Perceptions of People with Multiple Sclerosis.

Initial evidence suggests that computer-assisted cognitive rehabilitation may improve cognitive performance among people with multiple sclerosis (MS). Most studies of computer-assisted cognitive training have incorporated an individualized in-office/clinic approach for training. The purpose of this study was to explore the feasibility of home-based computer-assisted training and systematically examine the perceptions of people with MS regarding home use of the program. Qualitative data (written and verbal) obtained as part of a larger randomized clinical trial of a cognitive rehabilitation intervention were analyzed. The computer training component of the intervention included prescribed tracks and exercises on the Internet-based Neuropsychonline program. The majority of the participants used the program the recommended number of times per week and for the minimum number of minutes over the 8-week intervention. Although participants had notable negative perceptions and complaints about the program during the training experience, most of them acknowledged during training that use of the program helped them recognize cognitive limitations, create and practice strategies to increase cognitive function, and improve the quality of their daily life. Data from focus groups 3 months after the training included similar criticisms regarding lack of feedback and difficulties with the program as well as acknowledgment of the positive effects and a desire for continued access to the program. The findings suggest that while home training is feasible, careful preparation for use of the program is required.

Applying the mental models framework to carbon monoxide risk in northern Mexico.

OBJECTIVES: Low-income residents of northern Mexico rely on unvented heaters during the winter, a practice that puts them at elevated risk for carbon monoxide intoxication. The goal of this study is to develop a communication protocol for carbon monoxide intoxication risks among the primarily low socioeconomic status population of Ciudad Juárez, Chihuahua, Mexico. METHODS: The mental models risk communication approach was used to identify important gaps in public understanding. This approach consists of step-by-step assessment of information needs and effectiveness of risk communication efforts by using interviews and surveys. RESULTS: The mental models process uncovered a key technical misunderstanding, the subject population's belief that carbon monoxide can be seen or smelled, which may result in a risk-prone behavior: failure to use a carbon monoxide detector. A communication protocol was designed to address this and other knowledge gaps, and it produced significant improvements in subjects' knowledge in a pretest/posttest evaluation. CONCLUSIONS: The mental models process was successful in developing a communication instrument capable of improving knowledge in the subject population. Future research needs include assessing the extent to which this instrument succeeds in changing behavior and reducing the risk of carbon monoxide intoxication. Future interventional efforts may focus on encouraging people to use carbon monoxide detectors.