Docosahexaenoic acid-induced alteration of Thy-1 and CD8 expression on murine splenocytes

• Published in: Biochimica et biophysica acta 1995-05, Vol.1236 (1), p.39-50
• Main Authors: Jenski, Laura J, Bowker, Gretchen M, Johnson, Michael A, D. Ehringer, William, Fetterhoff, Terry, Stillwell, William
• Format: Article
• Language: English
• Subjects: ( n − 3) Fatty acid; AIDS/HIV; Animals; CD8; CD8 Antigens - biosynthesis; CD8-Positive T-Lymphocytes - metabolism; Cells, Cultured; Dietary Fats - administration & dosage; Docosahexaenoic acid; Docosahexaenoic Acids - administration & dosage; Docosahexaenoic Acids - pharmacology; Liposomes; Lymphocyte Activation; Male; Mice; Mice, Inbred BALB C; Spleen - drug effects; Spleen - metabolism; Thy-1; Thy-1 Antigens - biosynthesis
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/0005-2736(95)00034-Z

Here we test whether the incorporation of docosahexaenoic acid (DHA, 22:6), an ( n − 3) fatty acid, into lymphocyte membranes affects the expression of the surface proteins Thy-1.2 and CD8. DHA was incorporated into splenocytes by three methods: feeding mice diets containing menhaden (fish) oil, fusing splenocytes with DHA-containing phosphatidylcholine vesicles, and culturing splenocytes with DHA. Thy-1.2 and CD8 expression were measured by flow cytometry and complement-mediated lysis using a panel of monoclonal antibodies. As ( n − 3) fatty acid incorporation into the lymphocytes increased, the expression of one Thy-1.2 epitope and one CD8 epitope decreased; the expression of two CD8 epitopes increased. Although diet-induced changes in surface protein expression may result from selective migration of cell populations or the diet's effect on protein biosynthesis, fusion with lipid vesicles demonstrated that DHA-containing phospholipids can mediate a direct and immediate effect. The decrease in Thy-1.2 expression was sustained for more than a week after removal of ( n − 3) fatty acids from the diet, most likely due to retention of membrane-bound ( n − 3) fatty acids. Because Thy-1.2 and CD8 participate in T cell activation, modulation of their expression by DHA suggests that DHA, when serving as a membrane structural element, may alter immune function.