There is a growing need for immunological assays to test toxic and modulatory effects of chemicals. The assays should be easy to use, reproducible and superior to cell line-based assays. We have ...therefore developed a comprehensive portfolio of assays based on primary human blood cells that are suitable for testing chemical effects.
The flow cytometry-based assays were designed to target a wide range of human peripheral blood mononuclear cells and whole blood, including T cells, NK cells, B cells, basophils and innate-like T cells such as γδT, MAIT and NKT cells. We have selected a set of activation markers for each immune cell, e.g: CD154 (T cells), CD137, CD107a (NK cells), CD63 (basophils), CD69, CD83 (B cells), CD69, IFN-γ (MAIT cells) and we selected cell specific stimuli: aCD3 antibodies (T cells); E. coli and cytokines IL-12/15/18 (MAIT cells); CpG ODN2006, R848 or aCD40 antibodies (B cells), fMLP or aFcϵR1 (basophils) or K562 cells (NK cells).
By selecting immune cell-specific markers and cell-specific stimuli, we were able to induce particular immune responses from the targeted immune cells. For example, the response to stimulation with anti-CD3 antibodies was in 36.8% of CD107a+CD8+ cells. Cytokine stimulation induced the production of IFN-γ in 30% of MAIT cells. After stimulation with
, around 50% of MAIT cells produced TNF. About 40% of basophils responded to aFcƐR1 stimulation. Similar activation ranges were achieved in K562-stimulated NK cells.
Our test portfolio covers the most relevant immune cells present in human blood, providing a solid basis for
toxicity and immunomodulatory testing of chemicals. By using human blood, the natural composition of cells found in the blood can be determined and the effects of chemicals can be detected at the cellular level.
Abstract
Background
With the widespread availability of microarray technology for epigenetic research, methods for calling differentially methylated probes or differentially methylated regions have ...become effective tools to analyze this type of data. Furthermore, visualization is usually employed for quality check of results and for further insights. Expert knowledge is required to leverage capabilities of these methods. To overcome this limitation and make visualization in epigenetic research available to the public, we designed EpiVisR.
Results
The EpiVisR tool allows to select and visualize combinations of traits (i.e., concentrations of chemical compounds) and differentially methylated probes/regions. It supports various modes of enriched presentation to get the most knowledge out of existing data: (1) enriched Manhattan plot and enriched volcano plot for selection of probes, (2) trait-methylation plot for visualization of selected trait values against methylation values, (3) methylation profile plot for visualization of a selected range of probes against selected trait values as well as, (4) correlation profile plot for selection and visualization of further probes that are correlated to the selected probe. EpiVisR additionally allows exporting selected data to external tools for tasks such as network analysis.
Conclusion
The key advantage of EpiVisR is the annotation of data in the enriched plots (and tied tables) as well as linking to external data sources for further integrated data analysis. Using the EpiVisR approach will allow users to integrate data from traits with epigenetic analyses that are connected by belonging to the same individuals. Merging data from various data sources among the same cohort and visualizing them will enable users to gain more insights from existing data.
The exposome encompasses an individual's exposure to exogenous chemicals, as well as endogenous chemicals that are produced or altered in response to external stressors. While the exposome concept ...has been established for human health, its principles can be extended to include broader ecological issues. The assessment of exposure is tightly interlinked with hazard assessment. Here, we explore if mechanistic understanding of the causal links between exposure and adverse effects on human health and the environment can be improved by integrating the exposome approach with the adverse outcome pathway (AOP) concept that structures and organizes the sequence of biological events from an initial molecular interaction of a chemical with a biological target to an adverse outcome. Complementing exposome research with the AOP concept may facilitate a mechanistic understanding of stress-induced adverse effects, examine the relative contributions from various components of the exposome, determine the primary risk drivers in complex mixtures, and promote an integrative assessment of chemical risks for both human and environmental health.
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•Mechanistic understanding of the causal links between exposure and adverse effects can be improved.•AOP concept enhances understanding the exposome and its impact on adverse outcome.•Exposome and AOP can connect human health and environmental risk assessment.•Mixtures should be included in AOP concept.
Living with dogs appears to protect against allergic diseases and airway infections, an effect possibly linked with immunomodulation by microbial exposures associated with dogs. The aim of this study ...was to characterize the influence of dog ownership on house dust microbiota composition. The bacterial and fungal microbiota was characterized with Illumina MiSeq sequencing from floor dust samples collected from homes in a Finnish rural-suburban (LUKAS2, N = 182) birth cohort, and the results were replicated in a German urban (LISA, N = 284) birth cohort. Human associated bacteria variable was created by summing up the relative abundances of five bacterial taxa. Bacterial richness, Shannon index and the relative abundances of seven bacterial genera, mostly within the phyla Proteobacteria and Firmicutes, were significantly higher in the dog than in the non-dog homes, whereas the relative abundance of human associated bacteria was lower. The results were largely replicated in LISA. Fungal microbiota richness and abundance of Leucosporidiella genus were higher in dog homes in LUKAS2 and the latter association replicated in LISA. Our study confirms that dog ownership is reproducibly associated with increased bacterial richness and diversity in house dust and identifies specific dog ownership-associated genera. Dogs appeared to have more limited influence on the fungal than bacterial indoor microbiota.
Background There is evidence that microRNAs (miRNAs) are sensitive to environmental stressors, including tobacco smoke. On the other hand, miRNAs are involved in immune regulation, such as regulatory ...T (Treg) cell differentiation. The aim of the present study was to investigate the association between prenatal tobacco smoke exposure, miRNAs, and Treg cell numbers. Methods Within a prospective mother-child study (Lifestyle and Environmental Factors and Their Influence on Newborns Allergy Risk), we analyzed the expression of miR-155 and miR-223 together with Treg cell numbers in maternal blood during pregnancy, as well as in cord blood (n = 441). Tobacco smoke exposure was assessed based on questionnaire answers and maternal urine cotinine levels. Additionally, the concentration of smoking-related volatile organic compounds was measured in dwellings of study participants. Results Both maternal and cord blood miR-223 expressions were positively correlated with maternal urine cotinine levels. An association was also found between maternal miR-223 expression and indoor concentrations of benzene and toluene. High miR-223 expression was associated with lower Treg cell numbers in maternal and cord blood. Furthermore, children with lower Treg cell numbers at birth had a higher risk of atopic dermatitis during the first 3 years of life. The concentration of the toluene metabolite S-benzylmercapturic acid in maternal urine was associated with decreased cord blood, but not maternal blood, miR-155 expression. A relationship between miR-155 expression and Treg cell numbers was not found. Conclusions For the first time, we show that maternal tobacco smoke exposure during pregnancy correlates with the level of miRNA-223 expression in blood, with an effect on children's cord blood Treg cell numbers and subsequent allergy risk.
Background
Parabens, widely used as preservatives in cosmetics, foods, and other consumer products, are suspected of contributing to allergy susceptibility. The detection of parabens in the placenta ...or amniotic fluid raised concerns about potential health consequences for the child. Recently, an increased asthma risk following prenatal exposure has been reported. Here, we investigated whether prenatal paraben exposure can influence the risk for atopic dermatitis (AD).
Methods
261 mother‐child pairs of the German mother‐child study LINA were included in this analysis. Eight paraben species were quantified in maternal urine obtained at gestational week 34. According to the parental report of physician‐diagnosed AD from age 1 to 8 years, disease onset, and persistence, childhood AD was classified into four different phenotypes.
Results
4.6% (n = 12) and 12.3% (n = 32) of the children were classified as having very early‐onset AD (until age two) either with or without remission, 11.9% (n = 31) as early‐onset (after age two), and 3.1% (n = 8) as childhood‐onset AD (after age six). Exposure to ethylparaben and n‐butylparaben was associated with an increased risk to develop very early‐onset AD without remission (EtP: adj.OR/95% CI:1.44/1.04–2.00,nBuP:adj.OR/95% CI:1.95/1.22–3.12). The effects of both parabens were predominant in children without a history of maternal AD and independent of children's sex.
Conclusion
Prenatal EtP or nBuP exposure may increase children's susceptibility for persistent AD with disease onset at very early age. This association was particularly pronounced in children without a history of maternal AD, indicating that children without a genetic predisposition are more susceptible to paraben exposure.
Different paraben species, widely used as preservatives in consumer products, were detected in the urine of pregnant women. Prenatal ethylparaben and n‐butylparaben exposure are associated with an increased risk for very early‐onset atopic dermatitis without remission independent of the child's sex. This risk increase predominantly affects children without a history of maternal atopic dermatitis. Abbreviation: AD, atopic dermatitis
Both allergy-preventing and allergy-promoting effects have been reported. ...a deeper mechanistic understanding of how vitamin D is related to the regulation of immune reactivity and allergic ...inflammation is required. ...only 26% of the genes identified as regulated by vitamin D have a vitamin D response element in proximity to their transcription start site (TSS),1 indicating that additional mechanisms are involved in the transcriptional control by vitamin D. As an additional mechanism, epigenetically mediated transcriptional deregulation through vitamin D-induced changes in DNA methylation was suggested.2 Here, we studied DNA-methylation pattern on a genomewide scale at base-pair resolution in healthy newborn children with high and low vitamin D levels to elucidate the role of vitamin D in epigenetic programming of an allergy-protective or allergy-promoting immune reactivity.
In the first years of their lives, children develop the cognitive, social and emotional skills that will provide the foundations for their lifelong health and achievements. To increase their life ...prospects and reduce the long-term effects of early aversive conditions, it is therefore crucial to understand the risk factors that negatively affect child development and the factors that are instead beneficial. In this study, we tested (i) the effects of different social and environmental stressors on maternal stress levels, (ii) the dynamic relationship between maternal stress and child behavior problems during development, and (iii) the potential promotive (i.e. main) or protective (i.e. buffering) effect of siblings on child behavior problems during development.
We used longitudinal data from 373 mother-child pairs (188 daughters, 185 sons) from pregnancy until 10 years of age. We assessed maternal stress and child behavior problems (internalizing and externalizing) with validated questionnaires, and then used linear mixed models, generalized linear mixed models and longitudinal cross-lagged models to analyze the data.
Our results showed that higher maternal stress levels were predicted by socio-environmental stressors (i.e. the lack of sufficient social areas in the neighborhood). Moreover, prenatal maternal stress reliably predicted the occurrence of behavior problems during childhood. Finally, the presence of older siblings had a promotive function, by reducing the likelihood that children developed externalizing problems.
Overall, our results confirm the negative effects that maternal stress during pregnancy may have on the offspring, and suggest an important main effect of older siblings in promoting a positive child development.
Introduction More than 350,000 chemicals make up the chemical universe that surrounds us every day. The impact of this vast array of compounds on our health is still poorly understood. Manufacturers ...are required to carry out toxicological studies, for example on the reproductive or nervous systems, before putting a new substance on the market. However, toxicological safety does not exclude effects resulting from chronic exposure to low doses or effects on other potentially affected organ systems. This is the case for the microbiome-immune interaction, which is not yet included in any safety studies. Methods A high-throughput in vitro model was used to elucidate the potential effects of environmental chemicals and chemical mixtures on microbiome-immune interactions. Therefore, a simplified human intestinal microbiota (SIHUMIx) consisting of eight bacterial species was cultured in vitro in a bioreactor that partially mimics intestinal conditions. The bacteria were continuously exposed to mixtures of representative and widely distributed environmental chemicals, i.e. bisphenols (BPX) and/or per- and polyfluoroalkyl substances (PFAS) at concentrations of 22 µM and 4 µM, respectively. Furthermore, changes in the immunostimulatory potential of exposed microbes were investigated using a co-culture system with human peripheral blood mononuclear cells (PBMCs). Results The exposure to BPX, PFAS or their mixture did not influence the community structure and the riboflavin production of SIHUMIx in vitro . However, it altered the potential of the consortium to stimulate human immune cells: in particular, activation of CD8 + MAIT cells was affected by the exposure to BPX- and PFAS mixtures-treated bacteria. Discussion The present study provides a model to investigate how environmental chemicals can indirectly affect immune cells via exposed microbes. It contributes to the much-needed knowledge on the effects of EDCs on an organ system that has been little explored in this context, especially from the perspective of cumulative exposure.
Recent publications show that exposure to these chemicals may contribute to an increased risk of allergy development including asthma and atopic dermatitis.1,2 An immune modulatory capacity of these ...compounds is assumed but not fully elucidated by now.3 Epidemiological studies provide evidence that exposure to phthalates and their metabolites might be more critical in the prenatal period when the fetal immune system is developing.4 According to the fact that regulatory T (Treg) cells are key players in the modulation of immune responses, we asked whether phthalates may affect the number of these cells leading to the observed increased risk to develop atopic dermatitis.2 In a recent study, we demonstrated that low number of Treg cells at birth is associated with a higher risk to develop an atopic dermatitis within the first 3 years of life.5 In the present investigation, we aimed to evaluate whether a high maternal phthalate burden impacts the number of Treg cells in pregnancy as well as in early childhood. Associations between maternal urine phthalate metabolite concentrations and the number of Treg cells were calculated using a linear regression model adjusted for maternal atopic dermatitis, maternal smoking and/or ETS exposure at home, maternal education, cat ownership, previous births (presence of older siblings), and in addition (only for children) for sex and breast-feeding until 6 months. Treg cells Allergic outcomes, adjusted OR (95% CI)∗ Hay fever Sensitization to food allergens (fx5)† Sensitization to inhalant allergens (sx1)† 0-3rd year,3.6% (17 of 475) First year,15.3% (79 of 515) Second year,12.1% (41...
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