title: The impact of membrane lipid composition on macrophage activation in the immune defense against Rhodococcus equi and Pseudomonas aeruginosa.
abstract: Nutritional fatty acids are known to have an impact on membrane lipid composition of body cells, including cells of the immune system, thus providing a link between dietary fatty acid uptake, inflammation and immunity. In this study we reveal the significance of macrophage membrane lipid composition on gene expression and cytokine synthesis thereby highlighting signal transduction processes, macrophage activation as well as macrophage defense mechanisms. Using RAW264.7 macrophages as a model system, we identified polyunsaturated fatty acids (PUFA) of both the n-3 and the n-6 family to down-regulate the synthesis of: (i) the pro-inflammatory cytokines IL-1β, IL-6 and TNF-α; (ii) the co-stimulatory molecule CD86; as well as (iii) the antimicrobial polypeptide lysozyme. The action of the fatty acids partially depended on the activation status of the macrophages. It is particularly important to note that the anti-inflammatory action of the PUFA could also be seen in case of infection of RAW264.7 with viable microorganisms of the genera R. equi and P. aeruginosa. In summary, our data provide strong evidence that PUFA from both the n-3 and the n-6 family down-regulate inflammation processes in context of chronic infections caused by persistent pathogens.
authors.affiliation: Institute of Physiological Chemistry, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 1, 04103 Leipzig, Germany; E-Mails:  axel.schoeniger@vmf.uni-leipzig.de  (A.S.);  adolph@vetmed.uni-leipzig.de  (S.A.);  fuhrmann@vmf.uni-leipzig.de  (H.F.).
authors.forename: Axel
authors.initials: A
authors.lastname: Schoeniger
authors.forename: Stephanie
authors.initials: S
authors.lastname: Adolph
authors.forename: Herbert
authors.initials: H
authors.lastname: Fuhrmann
authors.forename: Julia
authors.initials: J
authors.lastname: Schumann
mesh_terms: D000193:Actinomycetales Infections / Q000276:immunology*; D000818:Animals; D051940:B7-2 Antigen / Q000378:metabolism; D002460:Cell Line; D004041:Dietary Fats / Q000494:pharmacology; D015536:Down-Regulation; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D007113:Immunity, Innate; D007249:Inflammation / Q000188:drug therapy; D053583:Interleukin-1beta / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D008262:Macrophage Activation; D008264:Macrophages / Q000737:chemistry* / Q000166:cytology; D008563:Membrane Lipids / Q000737:chemistry*; D051379:Mice; D009113:Muramidase / Q000378:metabolism; D053594:Myeloid Differentiation Factor 88 / Q000037:antagonists & inhibitors / Q000378:metabolism; D011552:Pseudomonas Infections / Q000276:immunology*; D011550:Pseudomonas aeruginosa; D016929:Rhodococcus equi; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; D004041:Dietary Fats; D005231:Fatty Acids, Unsaturated; D053583:Interleukin-1beta; D015850:Interleukin-6; D008563:Membrane Lipids; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D014409:Tumor Necrosis Factor-alpha; D009113:Muramidase