Modification of mononuclear cell function after incubation with albumin-bound unsaturated fatty acids or soybean oil emulsion

• Published in: APMIS : acta pathologica, microbiologica et immunologica Scandinavica Vol. 105; no. 7-12; pp. 671 - 679
• Main Authors: BØRSUM, KJETIL, AKSNES, JON, MÜLLER, FREDRIK, HAGVE, TOR-ARNE, KIERULF, PETER, ROLLAG, HALVOR
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-09-1997; Blackwell
• Subjects: Biological and medical sciences; Cells, Cultured; Emulsions; Fat Emulsions, Intravenous - metabolism; Fatty Acids - metabolism; Fatty Acids, Unsaturated - metabolism; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Immune response; Immunobiology; Leukocytes, Mononuclear - metabolism; linoleic acid; lipid emulsion; Lymphocyte Activation; lymphocyte activity; Membrane Fluidity; Modulation of the immune response (stimulation, suppression); mononuclear cell activity; phospholipids; Phospholipids - metabolism; plasma membrane; Respiratory Burst; Serum Albumin - metabolism; Soybean Oil - metabolism; unsaturated fatty acids; Immune response; Monocyte; Immunomodulation; Fat emulsion; Phospholipid; Activation; In vitro; Linoleic acid; Pig; Vertebrata; Mammalia; Mononuclear cell; Fluidity; Oleic acid; Plasma membrane; Unsaturated fatty acid; Artiodactyla; Soybean oil; Lymphocyte; Ungulata
• ISSN: 0903-4641; 1600-0463
• DOI: 10.1111/j.1699-0463.1997.tb05070.x

Administration of total parenteral nutrition (TPN) with soybean oil emulsion leads to a linoleic acid enrichment of the plasma membrane that may explain an in vivo activation of mononuclear cells (MNC) seen in our previous studies. Fatty acids from the lipid emulsion may have been accessible to MNC after endocytosis of lipid particles, or by direct uptake of fatty acids after lipoprotein lipase hydrolyzation of the emulsion triglycerides. To resemble the incorporation of fatty acids in vivo, we have modified MNC membrane lipid composition by incubation with different albumin‐bound unsaturated fatty acids (UFA) or soybean oil emulsion. After incubation with albumin‐bound linoleic and oleic acid, the unstimulated release of superoxide anion was unchanged, while zymosan‐stimulated release was 140% (n.s) and 112% (p<0.05) and phorbol‐myristate‐acetate (PMA)‐stimulated release 148% (p<0.05) and 124 % (p<0.05) of controls, respectively. Incubation with other UFAs or emulsion did not change superoxide anion release. Unstimulated lymphocyte proliferation increased 3 to 13‐fold (p<0.05) after incubation with all UFAs compared to controls, while UFA incubation did not change phytohemagglutinin (PHA) or PMA‐stimulated proliferation. Unstimulated lymphocyte proliferation was decreased after incubation with emulsion, while PHA/PMA‐stimulated proliferation was unchanged. Increase in membrane fluidity was detectable only after incubation with emulsion. The increased reactivity may have been caused by changes in the lipid environment surrounding membrane‐bound enzymes important for signal transduction through the plasma membrane.