Ege, M.J. et al. Prenatal farm exposure is related to the expression of receptors of the innate immunity and to atopic sensitization in school-age children. J. Allergy Clin. Immunol. 117, 817-823
We sought to investigate the role of maternal exposures to environments rich in microbial compounds for the development of atopic sensitization, asthma, and corresponding alterations in the innate immune system in offspring.
In the children of the cross-sectional Prevention of Allergy Risk Factors for Sensitization in Children Related to Farming and Anthroposophic Life Style study, asthma and atopy were assessed by means of standardized questionnaires (n = 8263) and serum IgE measurements (n = 2086). In a subsample (n = 322) gene expression of Toll-like receptors (TLR2 and TLR4) and CD14 was assessed. Maternal exposures were defined through questionnaire information.
Both atopic sensitization (adjusted odds ratio, 0.58; 95% CI, 0.39-0.86) and the gene expression of receptors of innate immunity were strongly determined by maternal exposure to stables during pregnancy, whereas current exposures had much weaker or no effects. A dose-response relation was found between the extent of upregulation of these genes and the number of different farm animal species the mother had encountered in her pregnancy. Each additional farm animal species increased the expression of TLR2, TLR4, and CD14 by a factor of 1.16 (95% CI, 1.07-1.26), 1.12 (95% CI, 1.04-1.2), and 1.10 (95% CI, 1.03-1.23), respectively.
Maternal exposure to an environment rich in microbial compounds might protect against the development of atopic sensitization and lead to upregulation of receptors of the innate immune system. The underlying mechanisms potentially operating through the intrauterine milieu or epigenetic inheritance await further elucidation.
When assessing risk factors of allergies in an infant's medical history, attention must also be paid to environmental exposures affecting the mother.
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Article: Ege, M.J. et al. Prenatal farm exposure is related to the expression of receptors of the innate immunity and to atopic sensitization in school-age children. J. Allergy Clin. Immunol. 117, 817-823
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- "Maternal genetic variants may determine the prenatal environment and thus play a role in the development of health conditions in their offspring, particularly for diseases with onset early in life.14,15 Many prenatal factors have been associated with IgE levels later in life.16,17 It is, therefore, conceivable that maternal genetic variants may have an influence on IgE levels in school-age children, particularly for genes in the IL-4/IL-13 pathway, as there is evidence that cord blood IgE was a predictor for allergy and asthma later in life.18,19 "
ABSTRACT: Purpose We investigated maternal genetic effects of four IL-4/IL-13 pathway genes as well as their interactions with the "Western or Eastern lifestyles/environments" on IgE in Karelian children. Methods This study included 609 children and their mothers. Total IgE levels in children and mothers were measured and 10 single nucleotide polymorphisms (SNPs) in IL-4, IL-4Ra, IL-13, and STAT6 were genotyped in mothers and their children. Results The maternal G allele of IL-13 130 (rs20541) was significantly (P=0.001) associated with decreased IgE in children in the Karelian population (Pooling Finnish and Russian children), as well as in Finnish (P=0.030) and Russian children (P=0.018). The IgE levels were significantly (P=0.001) higher in Russian children whose mothers were homozygous for the G allele of the IL-4Ra 50 (rs1805010) SNP than that in Russian children of mothers who were AG heterozygotes or AA homozygotes. After accounting for children's genotypes, we observed interactive effects on children's IgE for maternal IL-13 130 genotypes (P=0.014) and maternal IL-4Ra 50 genotypes (P=0.0003) with "Western or Eastern" lifestyles/environments. With the adjustment for multiple comparisons using a false discovery rate (FDR) of 0.05, the interactive effect of the maternal IL-4Ra50 SNP was significant. Conclusion Maternal genetic variants in IL-4/IL-13 pathway genes, such as IL-13 130 and IL-4Ra50, influenced IgE levels in school children that were independent of the children's genetic effects. These effects differ in "Western or Eastern" environments.Allergy, asthma & immunology research 07/2014; 6(4):350-6. DOI:10.4168/aair.2014.6.4.350 · 2.43 Impact Factor
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- "TLR-mediated innate response pathways are believed to attenuate allergic Th2-driven immune responses . Blood cells of infants of farming-exposed mothers exhibit upregulated expression of TLR2 and TLR4 [123,124]. MiRs are fine-tuners of TLR signaling and play a crucial role in endotoxin tolerance [125,126]. Enhanced exposure of lipopolysaccharides (LPS) in the farm environment may result in stronger LPS-mediated TLR4 activation in monocyte/macrophages and DCs that increase expression of miR-155, miR-146a, and miR-21, crucial regulatory miRs involved in thymic Treg maturation [127-133]. "
ABSTRACT: Epidemiological evidence confirmed that raw cow’s milk consumption in the first year of life protects against the development of atopic diseases and increases the number of regulatory T-cells (Tregs). However, milk’s atopy-protective mode of action remains elusive. This review supported by translational research proposes that milk-derived microRNAs (miRs) may represent the missing candidates that promote long-term lineage commitment of Tregs downregulating IL-4/Th2-mediated atopic sensitization and effector immune responses. Milk transfers exosomal miRs including the ancient miR-155, which is important for the development of the immune system and controls pivotal target genes involved in the regulation of FoxP3 expression, IL-4 signaling, immunoglobulin class switching to IgE and FcϵRI expression. Boiling of milk abolishes milk’s exosomal miR-mediated bioactivity. Infant formula in comparison to human breast- or cow’s milk is deficient in bioactive exosomal miRs that may impair FoxP3 expression. The boost of milk-mediated miR may induce pivotal immunoregulatory and epigenetic modifications required for long-term thymic Treg lineage commitment explaining the atopy-protective effect of raw cow’s milk consumption. The presented concept offers a new option for the prevention of atopic diseases by the addition of physiological amounts of miR-155-enriched exosomes to infant formula for mothers incapable of breastfeeding.Journal of Translational Medicine 02/2014; 12(1):43. DOI:10.1186/1479-5876-12-43 · 3.93 Impact Factor
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- "Environments rich in microbes, such as farming environments, appear to protect against the development of allergies in children, especially when the exposure is pre-natal . These protective effects are associated with alterations in both the neonatal innate ,  and adaptive  immune systems. These studies suggest that the microenvironment of the uterus plays a key role in shaping the infant's response to environmental stimuli, which subsequently influences the development of allergy . "
ABSTRACT: Intrauterine environmental exposures have been shown to influence neonatal immunity and subsequent allergic disease development. We have previously shown that fewer lipopolysaccharide (LPS)-stimulated eosinophil-basophil (Eo/B) colonies grow from cord blood (CB) of high-atopic risk infants, compared to low-atopic risk infants. In the present study, we investigated whether a surrogate ex vivo TH2 milieu (i.e., either IL-4 or IL-13) could represent an underlying mechanism to explain our previous findings. CB CD34+ cells from healthy donors were cultured with IL-4 or IL-13 (in combination with LPS) and assessed for Eo/B differentiation using methylcellulose cultures and flow cytometry for related intracellular signalling pathways. Pharmacological inhibitors were added to the methylcellulose cultures to determine the effect of blocking intracellular signalling in CB CD34+ cells in relation to Eo/B colony forming unit (CFU) formation. Stimulation of CD34+ cells with IL-4, but not IL-13, reduced Eo/B CFU formation in the presence of LPS; this was found to be dependent on IL-4Rα and not IL-13Rα1. Additionally, IL-4 reduced the expression of ERK 1/2 after LPS stimulation, which was recovered by inhibition of IL-4Rα. While IL-13 did not have an inhibitory effect on ERK 1/2 expression, inhibition of ERK 1/2 significantly reduced Eo/B CFU formation. Thus, the responsiveness of CB CD34+ progenitor cells to LPS is differentially regulated by the TH2 cytokines, IL-4 and IL-13. This may have implications for in utero interactions between placental-derived pro-allergic cytokines and neonatal progenitor cells influencing Eo/B-mediated inflammatory responses in early life.PLoS ONE 02/2014; 9(6):e100734. DOI:10.1371/journal.pone.0100734 · 3.23 Impact Factor