Effect of dietary fish oil on development and selected functions of murine inflammatory macrophages

• Published in: Journal of leukocyte biology Vol. 49; no. 6; pp. 592 - 598
• Main Authors: Hubbard, Neil E., Somers, Scott D., Erickson, Kent L.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Society for Leukocyte Biology 01.06.1991; Federation of American Societies for Experimental Biology
• Subjects: activational state; Administration, Oral; Animals; Biological and medical sciences; Cell Adhesion - drug effects; Cell Adhesion - physiology; Cell Movement - drug effects; Cell Movement - physiology; Cells, Cultured; Dietary Fats, Unsaturated - administration & dosage; Dietary Fats, Unsaturated - pharmacology; docosahexaenoic acid; Dose-Response Relationship, Drug; eicosapentaenoic acid; Female; Fish Oils - administration & dosage; Fish Oils - pharmacology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Histocompatibility Antigens Class II - metabolism; Immunobiology; Inflammation - pathology; Inflammation - physiopathology; Interferon-gamma - pharmacology; la expression; Lipopolysaccharides - pharmacology; Macrophages - drug effects; Macrophages - pathology; Macrophages - physiology; Mice; Modulation of the immune response (stimulation, suppression); peroxide production; Peroxides - metabolism; Phagocytosis - drug effects; Phagocytosis - physiology; Safflower Oil - administration & dosage; Safflower Oil - pharmacology; Tetradecanoylphorbol Acetate - pharmacology; Zymosan - pharmacology; Cell function; Immunomodulation; Induction; Rodentia; Cytokine; Biosynthesis; Inflammation; Fish oil; Vertebrata; Mammalia; Mouse; Restricted diet; Hydrogen peroxides; Gamma interferon; Macrophage
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/jlb.49.6.592

Inflammatory macrophages from mice fed diets containing menhaden fish oil (MFO) have a reduced capacity for cytotoxicity of mastocytoma cells upon activation with interferon‐γ (IFNγ) and lipopolysaccharide due to an altered responsiveness to IFNγ. In an effort to elucidate further how dietary MFO effects macrophage function, we have studied the maturation of inflammatory macrophages from mice fed MFO compared with mice fed safflower oil (SFO) using several processes that serve as markers of the activational state. No significant differences in the recruitment or percentage of peritoneal exudate cells as macrophages after thioglycollate injection and no differences in spreading, binding, or phagocytosis of sheep erythrocytes or phagocytosis of yeast by inflammatory macrophages were observed when the dietary groups were compared. However, MFO macrophages had an altered capacity for peroxide release when stimulated with unopsonized zymosan (10–200 μg/ml). Furthermore, to elucidate how MFO feeding could alter IFNγ‐induced responses of inflammatory macrophages, we assessed phorbol‐12‐myristate‐13‐acetate‐induced hydrogen peroxide production and expression of class II MHC determinants (la). There were no differences between macrophages from mice fed the two diets with respect to the production of peroxide when they were preincubated with 0.1–10 U/ml of IFNγ. However, MFO macrophages had greater peroxide production after enhancement with 100 U/ml of IFNγ. With respect to la induction, the percentage of macrophages responding to IFNγ was not altered by diet, and there were no differences in expression of la induced by 24 hr exposure to IFNγ. Thus the differential effect of MFO compared with SFO is probably mediated not by an alteration in the maturation of inflammatory macrophages but rather through the alteration of IFNγ‐induced functions such as peroxide production.