title: Host-microbial interactions in childhood atopy: toll-like receptor 4 (TLR4), CD14, and fecal Escherichia coli.
abstract: BACKGROUND
  Perturbations in the gut microbiota have been linked to atopic diseases. However, the development of atopic diseases depends not only on environmental factors (like microbial stimulation) but also on genetic factors. It is likely that particularly gene-environmental interactions in early life determine the development of atopy.
  
  
  OBJECTIVE
  We examine the interaction between detection of fecal Escherichia coli and genetic variations in the CD14 and Toll-like receptor 4 (TLR4) genes in relation to atopic manifestations.
  
  
  METHODS
  Within the Child, Parent and Health: Lifestyle and Genetic Constitution (KOALA) Birth Cohort Study, fecal samples of 957 one-month-old infants were collected and quantitatively screened for E coli. Fourteen haplotype-tagging polymorphisms in the genes TLR4 and CD14 were genotyped in 681 of the 957 children. Atopic outcomes were parentally reported eczema in the first 2 years of life and clinically diagnosed eczema and allergic sensitization at age 2 years. Multiple logistic regression was used to evaluate a multiplicative model of interaction.
  
  
  RESULTS
  Most of the single nucleotide polymorphisms (SNPs) showed no significant interaction with E coli exposure for both eczema and allergic sensitization. A borderline significant multiplicative interaction was found between E coli and the rs2569190 (CD14/-159) SNP regarding allergic sensitization. Furthermore, a statistically significant multiplicative interaction was found for the TLR4 SNP rs10759932 (P for interaction = .001). E coli colonization was associated with a decreased risk of sensitization only in children with the rs10759932 TT genotype (adjusted odds ratio, 0.31; 95% CI, 0.14-0.68) and not in children with the minor C allele. This interaction remained statistically significant after controlling for multiple testing.
  
  
  CONCLUSIONS
  The current study is the first to address the potential effect-modifying role of genetic variations in the relationship between the intestinal microbiota and allergy development.
authors.affiliation: Department of Epidemiology, Nutrition and Toxicology Research Institute Maastricht and Care and Public Health Research Institute, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands. j.penders@epid.unimaas.nl
authors.forename: John
authors.initials: J
authors.lastname: Penders
authors.forename: Carel
authors.initials: C
authors.lastname: Thijs
authors.forename: Monique
authors.initials: M
authors.lastname: Mommers
authors.forename: Ellen E
authors.initials: EE
authors.lastname: Stobberingh
authors.forename: Edward
authors.initials: E
authors.lastname: Dompeling
authors.forename: Naomi E
authors.initials: NE
authors.lastname: Reijmerink
authors.forename: Piet A
authors.initials: PA
authors.lastname: van den Brandt
authors.forename: Marjan
authors.initials: M
authors.lastname: Kerkhof
authors.forename: Gerard H
authors.initials: GH
authors.lastname: Koppelman
authors.forename: Dirkje S
authors.initials: DS
authors.lastname: Postma
mesh_terms: D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000235:genetics; D004926:Escherichia coli / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology*; D020022:Genetic Predisposition to Disease; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000235:genetics*; D007223:Infant; D007231:Infant, Newborn; D018950:Lipopolysaccharide Receptors / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D051197:Toll-Like Receptor 4 / Q000235:genetics* / Q000378:metabolism
chemical_list: D018950:Lipopolysaccharide Receptors; D051197:Toll-Like Receptor 4