title: The adjuvant effect of di-(2-ethylhexyl) phthalate is mediated through a PPARalpha-independent mechanism.
abstract: Previous studies in BALB/c mice revealed an adjuvant effect of di-(2-ethylhexyl) phthalate (DEHP) to simultaneously administered ovalbumin. DEHP is the most commonly used phthalate plasticizer. In vivo formed metabolites of DEHP are peroxisome-proliferator-activated receptor (PPAR) ligands, a group of chemicals that may have immunomodulatory properties. To study whether the PPARalpha receptor was involved in the adjuvant effect of DEHP, PPARalpha-deficient 129/Sv mice were exposed intraperitoneally to a mixture of OVA and DEHP, and the OVA-specific IgE, IgG1 and IgG2a responses were compared to the corresponding responses in the wild-type strain. The study showed that the adjuvant mechanism of DEHP is mediated through a PPARalpha-independent mechanism. Compared to mice only given OVA, DEHP induced highly increased levels of OVA-specific IgG1 and IgG2a, both in the wild-type and in the PPARalpha knock-out strains, indicating that DEHP is a mixed Th1/Th2 adjuvant.
authors.affiliation: Airway Allergy and Irritation Group, National Institute of Occupational Health, Denmark. stl@ami.dk
authors.forename: Søren Thor
authors.initials: ST
authors.lastname: Larsen
authors.forename: Gunnar Damgård
authors.initials: GD
authors.lastname: Nielsen
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D004051:Diethylhexyl Phthalate / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007114:Immunization; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D010047:Ovalbumin / Q000276:immunology; D047493:PPAR alpha / Q000235:genetics / Q000502:physiology*; D015203:Reproducibility of Results; D018417:Th1 Cells / Q000187:drug effects / Q000276:immunology; D018418:Th2 Cells / Q000187:drug effects / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D007074:Immunoglobulin G; D047493:PPAR alpha; D007073:Immunoglobulin E; D010047:Ovalbumin; D004051:Diethylhexyl Phthalate