Potential Biomarkers, Risk Factors, and Their Associations with IgE-Mediated Food Allergy in Early Life: A Narrative Review.

Food allergy (FA) affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. In the past few decades, the prevalence of allergic disease has been on the rise worldwide. Identified risk factors for FA include family history, mode of delivery, variations in infant feeding practices, prior diagnosis of other atopic diseases such as eczema, and social economic status. Identifying reliable biomarkers that predict the risk of developing FA in early life would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. There is also the potential to identify new therapeutic targets. This narrative review provides details on the genetic, epigenetic, dietary, and microbiome influences upon the development of FA and synthesizes the currently available data indicating potential biomarkers. Whereas there is a large body of research evidence available within each field of potential risk factors, there is a very limited number of studies that span multiple methodological fields, for example, including immunology, microbiome, genetic/epigenetic factors, and dietary assessment. We recommend that further collaborative research with detailed cohort phenotyping is required to identify biomarkers, and whether these vary between at-risk populations and the wider population. The low incidence of oral food challenge-confirmed FA in the general population, and the complexities of designing nutritional intervention studies will provide challenges for researchers to address in generating high-quality, reliable, and reproducible research findings.

Health relevance of the modification of low grade inflammation in ageing (inflammageing) and the role of nutrition.

Ageing of the global population has become a public health concern with an important socio-economic dimension. Ageing is characterized by an increase in the concentration of inflammatory markers in the bloodstream, a phenomenon that has been termed "inflammageing". The inflammatory response is beneficial as an acute, transient reaction to harmful conditions, facilitating the defense, repair, turnover and adaptation of many tissues. However, chronic and low grade inflammation is likely to be detrimental for many tissues and for normal functions. We provide an overview of low grade inflammation (LGI) and determine the potential drivers and the effects of the "inflamed" phenotype observed in the elderly. We discuss the role of gut microbiota and immune system crosstalk and the gut-brain axis. Then, we focus on major health complications associated with LGI in the elderly, including mental health and wellbeing, metabolic abnormalities and infections. Finally, we discuss the possibility of manipulating LGI in the elderly by nutritional interventions. We provide an overview of the evidence that exists in the elderly for omega-3 fatty acid, probiotic, prebiotic, antioxidant and polyphenol interventions as a means to influence LGI. We conclude that slowing, controlling or reversing LGI is likely to be an important way to prevent, or reduce the severity of, age-related functional decline and the onset of conditions affecting health and well-being; that there is evidence to support specific dietary interventions as a strategy to control LGI; and that a continued research focus on this field is warranted.

Impact of food processing and detoxification treatments on mycotoxin contamination.

Mycotoxins are fungal metabolites commonly occurring in food, which pose a health risk to the consumer. Maximum levels for major mycotoxins allowed in food have been established worldwide. Good agricultural practices, plant disease management, and adequate storage conditions limit mycotoxin levels in the food chain yet do not eliminate mycotoxins completely. Food processing can further reduce mycotoxin levels by physical removal and decontamination by chemical or enzymatic transformation of mycotoxins into less toxic products. Physical removal of mycotoxins is very efficient: manual sorting of grains, nuts, and fruits by farmers as well as automatic sorting by the industry significantly lowers the mean mycotoxin content. Further processing such as milling, steeping, and extrusion can also reduce mycotoxin content. Mycotoxins can be detoxified chemically by reacting with food components and technical aids; these reactions are facilitated by high temperature and alkaline or acidic conditions. Detoxification of mycotoxins can also be achieved enzymatically. Some enzymes able to transform mycotoxins naturally occur in food commodities or are produced during fermentation but more efficient detoxification can be achieved by deliberate introduction of purified enzymes. We recommend integrating evaluation of processing technologies for their impact on mycotoxins into risk management. Processing steps proven to mitigate mycotoxin contamination should be used whenever necessary. Development of detoxification technologies for high-risk commodities should be a priority for research. While physical techniques currently offer the most efficient post-harvest reduction of mycotoxin content in food, biotechnology possesses the largest potential for future developments.

Fluorescent SNAP-tag galectin fusion proteins as novel tools in glycobiology.

Galectins,ß-galactoside binding proteins, function in several physiological and pathological processes. The further evaluation of these processes as well as possible applications of galectins in diagnosis and therapy has raised high scientific interest. Therefore, easy and reliable test systems are necessary. Here we present the simple and cost-efficient production of recombinant human galectins as fusion proteins with SNAP-tag and fluorescent proteins. These constructs show binding specificities and oligomerisation properties generally comparable to recombinant galectins. Their direct fluorescence signal was utilised by ELISA-type assay and flow cytometry analysis with human and ovine mesenchymal stem cells (MSC). Flow cytometry demonstrated glycan mediated binding of His6-SNAP-YFP-Gal- 3 to both MSC types, which was specifically inhibited by lactose. Moreover, directed immobilisation by SNAP-tag technology onto benzylguanine- activated sepharose was utilised to prepare galectin affinity columns for glycoprotein analysis and purification. The SNAPtag directed coupling yielded up to three-fold higher binding capacities for the glycoprotein standard asialofetuin compared to nondirected coupled galectin suggesting improved functionality following directed coupling.

Directed covalent immobilization of fluorescently labeled cytokines.

Cytokines are important mediators coordinating inflammation and wound healing in response to tissue damage and infection. Therefore, immobilization of cytokines on the surface of biomaterials is a promising approach to improve biocompatibility. Soluble cytokines signal through receptors on the cell surface leading to cell differentiation, proliferation, or other effector functions. Random immobilization of cytokines on surfaces will result in a large fraction of inactive protein due to impaired cytokine--receptor interaction. We developed a strategy that combined (i) directed covalent coupling of cytokines, (ii) quantification of coupling efficiency through fluorescence detection, and (iii) a reliable protease cleavage assay to control orientation of coupling. For this purpose, fusion proteins of the SNAP-tag followed by an enterokinase recognition site, yellow fluorescent protein (YFP), and the cytokine of interest being either interleukin-6 (IL-6) or oncostatin M (OSM) were generated. The SNAP-tag is a derivative of O(6)-alkylguanine-DNA alkyltransferase that couples itself covalently to benzylguanine. Bioactivities of the SNAP-YFP-cytokines were shown to be comparable with the nontagged cytokines. Efficient coupling of SNAP-YFP-cytokines to benzylguanine-modified beads was demonstrated by flow cytometry. The fact that enterokinase treatment released most of the fluorescence from the beads is indicative for directed coupling and only marginal adsorptive binding. Cellular responses to SNAP-YFP-cytokine beads were analyzed in cellular lysates and by confocal microscopy indicating that the directionally immobilized cytokines are fully signaling competent with respect to the activation of ERK and STAT3. The strategy presented here is generally applicable for the directed covalent immobilization of fluorescently labeled proteins including the convenient and reliable control of coupling efficiency and orientation.

Development of an IL-6 inhibitor based on the functional analysis of murine IL-6Ralpha(1).

Dysregulated cytokine production contributes to inflammatory and proliferative diseases. Therefore, inhibition of proinflammatory mediators such as TNF, IL-1, and IL-6 is of great clinical relevance. Actual strategies are aimed at preventing receptor activation through sequestration of the ligand. Here we describe the development of an inhibitor of murine IL-6 based on fused receptor fragments. Molecular modeling-guided analysis of the murine IL-6Ralpha revealed that mutations in the Ig-like domain D1 severely affect protein function, although D1 is not directly involved in the ligand-binding interface. The resulting single chain IL-6 inhibitor (mIL-6-RFP) consisting of domains D1-D3 of mgp130, a flexible linker, and domains D1-D3 of mIL-6Ralpha is a highly potent and specific IL-6 inhibitor. mIL-6-RFP will permit further characterization of the role of IL-6 in various disease models and could ultimately lead to anti-IL-6 therapy.