title: Exposure to a farm environment is associated with T helper 1 and regulatory cytokines at age 4.5 years.
abstract: BACKGROUND
  Farm exposure has been shown to protect from childhood asthma and allergic diseases, but underlying immunological mechanisms are not clear yet.
  
  
  OBJECTIVE
  To explore whether farming lifestyle determines cytokine profile of peripheral blood mononuclear cells (PBMCs) of 4.5-year-old children (n = 88) from the Finnish PASTURE birth cohort study.
  
  
  METHODS
  We analysed regulatory (IL-10, IL-2), T helper 1 (Th1)-associated (IL-12, IFN-γ), inflammatory (IL-1β, TNF, CXCL8) and Th2-associated (IL-13) cytokines in unstimulated PBMCs and after a short-term (5 h) stimulation with lipopolysaccharide (LPS). Specific farm exposures (stables, hay barn, farm milk) at age 4 years were assessed from questionnaires.
  
  
  RESULTS
  The unstimulated PBMCs of farm children produced more IL-10 (GMR 1.22, P = 0.032), IL-12 (GMR 1.24, P = 0.012) and IFN-γ (GMR 1.24, P = 0.024) than those of non-farm children. Also, specific farm exposures were associated with higher spontaneous production of cytokines. The number of specific farm exposures tended to be dose dependently associated with higher spontaneous production of IFN-γ (test for trends, P = 0.013) and lower LPS-induced production of TNF (test for trends, P = 0.025).
  
  
  CONCLUSIONS
  Farming lifestyle seemed to be associated with increased spontaneous production of Th1 and regulatory cytokines. Decreased TNF responses to short-term LPS stimulation in farm-exposed children may imply tolerogenic immune mechanisms. These novel findings might contribute to the asthma and allergy protection in farm environment.
authors.affiliation: Department of Environmental Science, University of Eastern Finland, Kuopio, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Kääriö
authors.affiliation: Department of Environmental Science, University of Eastern Finland, Kuopio, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Huttunen
authors.affiliation: Department of Health Protection, National Institute for Health and Welfare, Kuopio, Finland.
authors.forename: A M
authors.initials: AM
authors.lastname: Karvonen
authors.affiliation: Department of Pulmonary and Allergy, University Children's Hospital Munich, LMU Munich, Munich, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Schaub
authors.affiliation: Department of Pulmonary and Allergy, University Children's Hospital Munich, LMU Munich, Munich, Germany.
authors.forename: E
authors.initials: E
authors.lastname: von Mutius
authors.affiliation: Department of Health Protection, National Institute for Health and Welfare, Kuopio, Finland.|Department of Public Health, University of Helsinki, Helsinki, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Pekkanen
authors.affiliation: Department of Environmental Science, University of Eastern Finland, Kuopio, Finland.|Department of Health Protection, National Institute for Health and Welfare, Kuopio, Finland.
authors.forename: M-R
authors.initials: MR
authors.lastname: Hirvonen
authors.affiliation: Department of Environmental Science, University of Eastern Finland, Kuopio, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Roponen
mesh_terms: D000367:Age Factors; D000383:Agriculture; D002478:Cells, Cultured; D002675:Child, Preschool; D016207:Cytokines / Q000378:metabolism*; D004781:Environmental Exposure; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008019:Life Style; D008297:Male; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism*; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism*
chemical_list: D016207:Cytokines
keywords: childhood; cytokine; farming; lipopolysaccharide