Docosahexaenoic acid-induced alteration of Thy-1 and CD8 expression on murine splenocytes.
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.
Jenski
L J
LJ
Department of Biology, Indiana University-Purdue University at Indianapolis, IN 46202-5132, USA.
Bowker
G M
GM
Johnson
M A
MA
Ehringer
W D
WD
Fetterhoff
T
T
Stillwell
W
W
D000818:Animals; D016827:CD8 Antigens / Q000096:biosynthesis*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D002478:Cells, Cultured; D004041:Dietary Fats / Q000008:administration & dosage; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D008081:Liposomes; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000187:drug effects / Q000378:metabolism*; D018800:Thy-1 Antigens / Q000096:biosynthesis*
D016827:CD8 Antigens; D004041:Dietary Fats; D008081:Liposomes; D018800:Thy-1 Antigens; D004281:Docosahexaenoic Acids