(n-3) Polyunsaturated fatty acids modulate the expression of functionally associated molecules on human monocytes in vitro.
Diets rich in (n-3) polyunsaturated fatty acids (PUFA) are associated with suppression of the immune system, but the mechanisms are unclear. Specific immune responses are initiated by antigen-presenting cells. This study examines the in vitro effect of the (n-3) PUFA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the expression of cell surface molecules required for normal antigen-presenting cell function on human blood monocytes. Monocytes were incubated with or without EPA or DHA for 48 h at 37 degrees C. Following incubation, expression of major histocompatibility complex (MHC) class II molecules (HLA-DR, -DP and -DQ) and adhesion molecules [intercellular adhesion molecule-1 (ICAM-1) and leucocyte function associated antigen-1] was quantified by flow cytometry. In the presence of EPA alone there was a significantly lower median intensity of expression of HLA-DR and ICAM-1 relative to incubations without EPA. In contrast, significantly greater median intensities of expression of HLA-DR and -DP were observed following incubation with DHA. In parallel experiments, where monocytes were simultaneously activated by the addition of interferon-gamma to the cultures, median expression intensities of HLA-DR, -DP and ICAM-1 were significantly lower in the presence of either EPA or DHA compared with incubations without the (n-3) PUFA. These findings support previous animal studies that suggest that (n-3) PUFA can influence immune reactivity by modulating antigen-presenting cell function.
Hughes
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DA
Department of Nutrition, Diet and Health, Institute of Food Research, Norwich Laboratory, United Kingdom.
Southon
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Pinder
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AC
D000328:Adult; D002478:Cells, Cultured; D004281:Docosahexaenoic Acids / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015118:Eicosapentaenoic Acid / Q000494:pharmacology; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D005260:Female; D005434:Flow Cytometry; D006681:HLA-D Antigens / Q000096:biosynthesis*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis*; D007371:Interferon-gamma / Q000494:pharmacology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000096:biosynthesis*; D008297:Male; D009000:Monocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D011994:Recombinant Proteins
D015525:Fatty Acids, Omega-3; D006681:HLA-D Antigens; D016169:Lymphocyte Function-Associated Antigen-1; D011994:Recombinant Proteins; D018799:Intercellular Adhesion Molecule-1; D004281:Docosahexaenoic Acids; D007371:Interferon-gamma; D015118:Eicosapentaenoic Acid