title: n-3 Fatty acids inhibit transcription of human IL-13: implications for development of T helper type 2 immune responses.
abstract: Fish oil supplementation during pregnancy has been associated with lower levels of cord blood IL-13, suggesting that the administration of n-3 fatty acids may attenuate the development of allergic disease. The present study aimed to investigate the mechanism by which n-3 fatty acid administration influences the production of IL-13. Pregnant BALB/c mice were fed nutritionally complete high-fat diets (15 %, w/w) with an n-3 fatty acid-enriched (DHA 1 %, w/w) or control diet (0 % DHA) immediately following delivery. Pups were exposed during suckling and weaned to the maternal diet for the remainder of the study. The production of IL-13, IL-4, IL-10 and interferon-γ from the splenocytes of ovalbumin (ova)-sensitised animals was assessed following in vitro ova stimulation or unstimulated conditions. Human T helper type 2 (Th2) cells were mitogen-stimulated in the presence or absence of DHA (10 μM) and assessed for IL-13 and IL-4 expression using intracellular flow cytometry. The influence on transcriptional activation was studied using a human IL-13 promoter reporter construct and electromobility shift assay. Ova-activated splenocytes from DHA-fed mice produced less IL-13 (57.2 (se 21.7) pg/ml) and IL-4 (7.33 (SE 3.4) pg/ml) compared with cells from the animals fed the control diet (161.5 (SE 45.0), P< 0.05; 33.2 (SE 11.8), P< 0.05). In vitro, DHA inhibited the expression of IL-13 protein from human Th2 cells as well as transcriptional activation and binding of the transcription factors cyclic AMP response element binding and activating transcription factor 2 to the human IL-13 promoter. These data indicate the potential of n-3 fatty acids to attenuate IL-13 expression, and suggest that they may subsequently reduce allergic sensitisation and the development of allergic disease.
authors: Department of Medicine, Heritage Medical Research Centre, University of Alberta, Edmonton, AB, Canada.
authors: Emily
authors: E
authors: MacLean
authors: Norman
authors: N
authors: Madsen
authors: Harissios
authors: H
authors: Vliagoftis
authors: Catherine
authors: C
authors: Field
authors: Lisa
authors: L
authors: Cameron
mesh_terms: D000818:Animals; D059305:Diet, High-Fat; D004281:Docosahexaenoic Acids; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000517:prevention & control; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D018793:Interleukin-13 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics*; D015847:Interleukin-4 / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D013154:Spleen / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D018418:Th2 Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D015525:Fatty Acids, Omega-3; D018793:Interleukin-13; D016753:Interleukin-10; D015847:Interleukin-4; D004281:Docosahexaenoic Acids; D007371:Interferon-gamma; D010047:Ovalbumin