Docosahexaenoic acid changes lipid composition and interleukin-2 receptor signaling in membrane rafts

Abstract

Polyunsaturated fatty acids, including docosahexaenoic acid (DHA, 22:6n-3), modulate immune responses and exert beneficial immunosuppressive effects, but the molecular mechanisms inhibiting T-cell activation are not yet elucidated. Lipid rafts have been shown to play an important role in the compartmentalization and modulation of cell signaling. We investigated the role of DHA in modulating the lipid composition in lipid rafts and membrane subdomain distribution of interleukin-2 (IL-2) receptor signaling molecules. We found that DHA altered lipid components of rafts and modified the IL-2-induced Janus kinase-signal transducer and activator of transcription (STAT) signaling pathway by partially displacing IL-2 receptors from lipid rafts. We fractionated plasma membrane subcellular compartments and discovered that certain amounts of STAT5a and STAT5b existed in detergent-resistant plasma membrane fractions of T-cells. After DHA treatment, STAT5a and STAT5b were not detected in lipid raft fractions and were located in detergent-soluble fractions.These data demonstrate for the first time that DHA alters the lipid composition of membrane microdomains and suppresses IL-2 receptor signaling in T-cells. Thus, our data provide evidence for a functional modification in lipid rafts by DHA treatment and explain PUFA-mediated immunosuppressive effects. Polyunsaturated fatty acids, including docosahexaenoic acid (DHA, 22:6n-3), modulate immune responses and exert beneficial immunosuppressive effects, but the molecular mechanisms inhibiting T-cell activation are not yet elucidated. Lipid rafts have been shown to play an important role in the compartmentalization and modulation of cell signaling. We investigated the role of DHA in modulating the lipid composition in lipid rafts and membrane subdomain distribution of interleukin-2 (IL-2) receptor signaling molecules. We found that DHA altered lipid components of rafts and modified the IL-2-induced Janus kinase-signal transducer and activator of transcription (STAT) signaling pathway by partially displacing IL-2 receptors from lipid rafts. We fractionated plasma membrane subcellular compartments and discovered that certain amounts of STAT5a and STAT5b existed in detergent-resistant plasma membrane fractions of T-cells. After DHA treatment, STAT5a and STAT5b were not detected in lipid raft fractions and were located in detergent-soluble fractions. These data demonstrate for the first time that DHA alters the lipid composition of membrane microdomains and suppresses IL-2 receptor signaling in T-cells. Thus, our data provide evidence for a functional modification in lipid rafts by DHA treatment and explain PUFA-mediated immunosuppressive effects. Polyunsaturated fatty acids, particularly the n-3 series, modulate the immune response and especially affect T-cell function (1Zurier R.B. Fatty acids, inflammation and immune response.Prostaglandins Leukot. Essent. Fatty Acids. 1993; 48: 57-62Google Scholar). Therefore, they are used clinically as immunosuppressive agents (2Van der Heide J.J. Biol H.J. Donker J.M. Wilmink J.M. Tegzess A.M. Effect of dietary fish oil on renal function and rejection in cyclosporine-treated recipients of renal transplants.N. Engl. J. Med. 1993; 329: 769-773Google Scholar) for various inflammatory diseases (3Belluzzi A. Brignola C. Campieri M. Pera A. Boschi S. Miglioli M. Effect of an enteric-coated fish-oil preparation on relapses in Crohn's disease.N. Engl. J. Med. 1996; 334: 1557-1560Google Scholar, 4Cappelli P. DiLiberato L. Stuard S. Ballone E. Albertazzi A. N-3 polyunsaturated fatty acid supplementation in chronic progressive renal disease.J. Nephrol. 1997; 10: 157-162Google Scholar, 5Cleland L.G. French J.K. Betts W.H. Murphy G.A. Elliott M.J. Clinical and biochemical effects of dietary fish oil supplements in rheumatoid arthritis.J. Rheumatol. 1988; 15: 1471-1475Google Scholar, 6Kremer J.M. Jubiz W. Michalek A.E.A. Fish-oil fatty acid supplementation in active rheumatoid arthritis. A double-blinded, controlled, crossover study.Ann. Intern. Med. 1987; 106: 497-504Google Scholar). Moreover, they have also been associated with the concept of immunonutrition. Their presence in cell membrane phospholipids can increase membrane fluidity and regulate the functions of membrane receptors and enzymes. The immunomodulatory effects of PUFAs are associated with their ability to inhibit T-cell activation (7Brouard C. Pascaud M.M. Effects of moderate dietary supplementations with n-3 fatty acids on macrophage and lymphocyte phospholipids and macrophage eicosanoid synthesis in the rat.Biochim. Biophys. Acta. 1990; 1047: 19-28Google Scholar, 8Rossetti R.G. Seiler C.M. DeLuca P. Laposata M. Zurier R.B. Oral administration of unsaturated fatty acids: effects on human peripheral blood T lymphocyte proliferation.J. Leukoc. Biol. 1997; 62: 438-443Google Scholar). However, this molecular alteration of PUFA-induced T-cell inhibition has not yet been elucidated. Lipid rafts are specialized in membrane microdomains, which are insoluble in nonionic detergents and can be isolated as detergent-resistant membrane domains. A large number of signaling proteins are targeted to lipid rafts. Therefore, lipid rafts serve as signaling platforms to facilitate efficient and specific signal transduction in living cells. Some findings have indicated that several proteins involved in the signaling pathway via the T-cell receptor, B-cell receptor, and IgE receptor are within lipid raft compartments (9Dillon S.R. Mancini M. Rosen A. Schlissel M.S. Annexin V binds to viable B cells and colocalizes with a marker of lipid rafts upon B cell receptor activation.J. Immunol. 2000; 164: 1322-1332Google Scholar, 10Stulnig T.M. Huber J. Leitinger N. Imre E.M. Angelisová P. Nowotny P. Waldhäusl W. Polyunsaturated eicosapentaenoic acid displaces proteins from membrane rafts by altering raft lipid composition.J. Biol. Chem. 2001; 276: 37335-37340Google Scholar). Many of the critical signaling components involved in the T-cell receptor-mediated signal pathway are localized in rafts, including Fyn, Lck, and LAT Src family kinases (10Stulnig T.M. Huber J. Leitinger N. Imre E.M. Angelisová P. Nowotny P. Waldhäusl W. Polyunsaturated eicosapentaenoic acid displaces proteins from membrane rafts by altering raft lipid composition.J. Biol. Chem. 2001; 276: 37335-37340Google Scholar, 11Stefanova I. Ho⊘ejší V. Ansotegui I.J. Knapp W. Stockinger H. GPI-anchored cell-surface molecules complexed to protein tyrosine kinases.Science. 1991; 254: 1016-1019Google Scholar, 12Shenoy-Scaria A.M. Kwong J. Fujita T. Olszowy M.W. Shaw A.S. Lublin D.M. Signal transduction through decay-accelerating factor. Interaction of glycosyl-phosphatidylinositol anchor and protein tyrosine kinases p56lck and p59fyn.J. Immunol. 1992; 149: 3535-3541Google Scholar). G-proteins (13Moffett S. Brown D.A. Linder M.E. Lipid-dependent targeting of G proteins into rafts.J. Biol. Chem. 2000; 275: 2191-2198Google Scholar) and endothelial nitric oxide synthase (14Gratton J.P. Fontana J. O'Connor D.S. García-Cardeña G. Timothy T.J. McCabe J. Sessa W.C. Reconstitution of an endothelial nitric-oxide synthase (eNOS), hsp90, and caveolin-1 complex in vitro. Evidence that hsp90 facilitates calmodulin stimulated displacement of eNOS from caveolin-1.J. Biol. Chem. 2000; 275: 22268-22272Google Scholar) are also enriched in rafts. PUFA supplementation inhibited T-lymphocyte activation by modifying detergent-insoluble membrane domains and displacing signaling proteins from lipid rafts in T-cells (15Stulnig T.M. Berger M. Sigmund T. Raederstorff D. Stockinger H. Waldhäusl W. Polyunsaturated fatty acids inhibit T cell signal transduction by modification of detergent-insoluble membrane domains.J. Cell Biol. 1998; 43: 637-644Google Scholar). The interleukin-2R (IL-2R) subunits complex (α, β, and γc) is involved in both proliferative and activation-induced cell death signaling of T-cells. The high-affinity IL-2 receptors consist of the IL-2Rα chain, a 55 kDa transmembrane glycoprotein with 251 amino acids, and IL-2Rβ and IL-2Rγc, which contribute to IL-2 binding and mediate signal transduction. Binding of IL-2 to the IL-2R results in the activation of Janus kinase-1 (JAK1) and JAK3 and their phosphorylation and activation (16Holowka D. and lipid raft components are by the Cell 2000; Scholar). phosphorylation of tyrosine in receptor results in the of the signal transducer and activator of transcription (STAT) T. A. H. activation of and by with IL-2 receptor Scholar). phosphorylation of proteins to their to the proteins regulate through IL-2R are important in the activation of in our that and are associated with lipid rafts of T-cells and that eicosapentaenoic acid lipid raft and the distribution of and in the plasma membrane and IL-2R signaling the the immunomodulatory effects of docosahexaenoic acid (DHA, 22:6n-3), the unsaturated fatty acid found in by the raft lipid composition and the of molecules of IL-2R signaling in both rafts and fractions. Thus, our data provide evidence for a functional modification in lipid rafts by DHA treatment and explain PUFA-mediated immunosuppressive effects. and acid were from and were also from and modified were from IL-2 and the were from IL-2Rα IL-2Rβ and from were used for of and STAT5b as as and were from from The and from from and were from The human T-cell in with and and with the modification of the cells were for in modified with fatty with the of DHA acid from in acid as a is the fatty acid to be to fatty acids are in human and this fatty acid shown not to PUFA and the membrane subdomain distribution of proteins with with The role of and in signaling by IL-2 family 2000; Scholar). The cells were with for to lipid rafts. After with IL-2 for cells were and Lipid rafts were isolated from T-cells as M. G. V. Waldhäusl W. T.M. LAT displacement from lipid rafts as a molecular for the inhibition of T cell signaling by polyunsaturated fatty Biol. Chem. Scholar) by The cells were in and in and and of of of of of of of of and of were on for with an of in and with of by of The were to for with a in an of were from the of the by The cells were with with of and with is to a of to of of in the for cells were with the cells were in and by on were with The proteins in fractions isolated from were by on a and to of and and and of and and were to with the and the were to and detergent-soluble fractions from and T-cells were of of acid as an by for After of and of were and to for The by and in of of which and by on a The with a an and a for to for and to for with a of The fatty acid composition is as The of in fatty acid raft and membrane fractions of and T-cells by in detergent-resistant and detergent-soluble fractions from and T-cells were The were with of and and and of and with the of of The and of and for The by and The on a of The and the A of and B of on a from with a The the through a V V and a to The and were with to the molecular of the The of and were both The The were as as time and as time in the and in the the displacement of IL-2R from membrane rafts be to altered fatty acid composition in lipid rafts, isolated rafts and T-cells. T-cells were with the n-3 polyunsaturated fatty acids acid acid and were in raft fractions with of cells The of acid and acid were also in raft fractions of cells with cells. from cells fatty acids acid and acid with rafts of cells. The n-3 and the of n-3 PUFAs to PUFAs were in rafts from T-cells with rafts from cells. DHA treatment the of polyunsaturated fatty acids in raft fractions in T-cells and altered the lipid of membrane acid composition of raft and fractions from cells and fractions of and T-cells with fractions of cells fractions of and T-cells with fractions of cells with fractions of cells rafts of T-cells with fractions of cells rafts of T-cells with fractions of cells with fractions of cells rafts of T-cells with fractions of cells with fractions of cells rafts of T-cells fractions of and T-cells with fractions of cells with fractions of cells rafts of T-cells with fractions of cells with fractions of cells with fractions of cells with fractions of cells fractions of and T-cells with fractions of cells rafts of T-cells with fractions of cells with fractions of cells with fractions of cells with fractions of cells with fractions of cells rafts of T-cells with fractions of cells rafts of T-cells fractions of and T-cells fatty with fractions of cells fatty with fractions of cells with 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fractions of cells fractions of T-cells in rafts with fractions of cells in rafts with fractions of cells fractions of T-cells in rafts with fractions of cells fractions of T-cells in rafts with fractions of cells in rafts with fractions of cells rafts of T-cells in rafts with fractions of cells rafts of T-cells in rafts with fractions of cells fractions of T-cells in rafts with fractions of cells in rafts with fractions of cells rafts of T-cells fractions of T-cells in rafts with fractions of cells rafts of T-cells in rafts with fractions of cells rafts of T-cells fractions of T-cells T-cells were with DHA which used as a Lipid rafts were isolated by were by and are in of of in rafts with fractions of cells in rafts with fractions of cells rafts of T-cells rafts of T-cells fractions of T-cells in rafts with fractions of cells in a fatty raft from T-cells and fractions of T-cells in rafts with fractions of cells in rafts with fractions of cells rafts of T-cells fractions of T-cells in 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S. G. of and kinases in T lymphocyte plasma Biol. 10: Scholar, E. rafts in cell 1997; Scholar). be used to lipid rafts on the plasma and caveolin-1 is the of in lipid rafts. the of caveolin-1 in lipid rafts After treatment, lipid rafts were as indicated by the of caveolin-1 in We investigated IL-2R subunits were associated with lipid rafts and DHA the of IL-2R in lipid rafts. The cells were stimulated for with IL-2 L. of protein raft and T cell signaling by and polyunsaturated fatty Biol. Chem. 2000; 275: Scholar). The of a protein with membrane rafts is and were fractionated by of fractions from that IL-2Rα detected in detergent-resistant membrane fractions of T-cells with the nonionic The IL-2Rβ and were also detected in the lipid raft fractions but not in the membrane fractions IL-2R were enriched in lipid rafts and localized within lipid raft Lipid rafts play an important role in the of the IL-2R signaling After DHA treatment, and were detected not in raft fractions but also in membrane fractions which indicated that IL-2R from lipid rafts this results that DHA lipid raft and the distribution of and in the plasma membrane and IL-2R signaling. After by and JAK3 kinases are associated with the IL-2R and can tyrosine phosphorylation of and JAK3 which is critical for IL-2R signal transduction. We the of and IL-2-induced tyrosine the shown in and were detected in membrane fractions. After DHA treatment, found the presence of and in the but their with that in cells treatment suppresses the of and in detergent-soluble T-cells were in the presence of DHA for and stimulated for with The were by the nonionic and lipid rafts as as detergent-soluble were fractionated by The proteins were by and with and STAT5a and STAT5b transcription signal from the plasma membrane to the by this investigated lipid rafts are involved in signaling. The data in that large amounts of STAT5a and STAT5b were associated with membrane fractions and that of STAT5a and STAT5b were localized in plasma membrane raft fractions. However, the tyrosine phosphorylation of detected in rafts. After DHA treatment, STAT5a and STAT5b were not detected in detergent-resistant lipid raft fractions and were in detergent-soluble fractions. STAT5a and STAT5b proteins were from raft fractions to membrane fractions in T-cells and and the tyrosine phosphorylation of as is evidence for the effects of n-3 PUFAs on inflammatory and they exert beneficial effects in various inflammatory The of n-3 polyunsaturated fatty Biol. Chem. Scholar). DHA is of the molecules polyunsaturated fatty acids interleukin-2 and the of and 1997; Scholar). have that several signaling proteins are enriched in lipid rafts and can be from membrane rafts by (15Stulnig T.M. Berger M. Sigmund T. Raederstorff D. Stockinger H. Waldhäusl W. Polyunsaturated fatty acids inhibit T cell signal transduction by modification of detergent-insoluble membrane domains.J. Cell Biol. 1998; 43: 637-644Google Scholar, V. M. a role in signaling via Scholar). The raft lipid composition is also altered However, is the biochemical alteration of the lipid in rafts by PUFA treatment, which be the molecular for PUFAs displacing proteins from membrane rafts. has not been that DHA the fatty composition in lipid rafts and alters the lipid provide biochemical evidence for the displacement of proteins in IL-2R signaling from lipid rafts in the fatty acid composition and fatty in phospholipids in detergent-resistant rafts and membrane fractions of and T-cells. T-cells were with the n-3 PUFAs and were enriched in raft fractions with of cells. DHA treatment in a increase of unsaturated fatty in rafts from T-cells with cells. fatty acids, as acid and were also in raft fractions of cells with and acid were alteration indicated that cells to lipid composition in rafts by the fatty this is PUFAs proteins from rafts and affect and transmembrane proteins in rafts by with fatty (15Stulnig T.M. Berger M. Sigmund T. Raederstorff D. Stockinger H. Waldhäusl W. Polyunsaturated fatty acids inhibit T cell signal transduction by modification of detergent-insoluble membrane domains.J. Cell Biol. 1998; 43: 637-644Google Scholar). The alteration in membrane fatty composition affect membrane in the and also has effects on the membrane subdomain distribution of proteins (10Stulnig T.M. Huber J. Leitinger N. Imre E.M. Angelisová P. Nowotny P. Waldhäusl W. Polyunsaturated eicosapentaenoic acid displaces proteins from membrane rafts by altering raft lipid composition.J. Biol. Chem. 2001; 276: 37335-37340Google Scholar). Lipid alteration of including and in lipid rafts have effects on displacing proteins from the functional lipid rafts. treatment in T-cells in the of PUFAs in the as as the of rafts (10Stulnig T.M. Huber J. Leitinger N. Imre E.M. Angelisová P. Nowotny P. Waldhäusl W. Polyunsaturated eicosapentaenoic acid displaces proteins from membrane rafts by altering raft lipid composition.J. Biol. Chem. 2001; 276: 37335-37340Google Scholar). Therefore, the of fatty acids in raft not in the lipid and but also in the membrane lipid and DHA DHA treatment the of with and of and fatty acids and is to by the amounts of and unsaturated of fatty acids and of with in rafts of cells with cells of the fatty composition of and affect the displacement of proteins from lipid rafts (10Stulnig T.M. Huber J. Leitinger N. Imre E.M. Angelisová P. Nowotny P. Waldhäusl W. Polyunsaturated eicosapentaenoic acid displaces proteins from membrane rafts by altering raft lipid composition.J. Biol. Chem. 2001; 276: 37335-37340Google Scholar). with and with and and with and in rafts in cells with cells DHA treatment the fatty composition of from the in rafts. Thus, the of fatty in the and lipid of lipid rafts from cells play an important role in raft and lipid this found that IL-2 in and proteins were detected in the fractions of membrane lipid rafts with the data of and J. A. G. and signaling of the interleukin-2 receptor in human T cell J. Scholar). also and that and subunits receptor in lipid rafts H. H. the and of transcription pathway in endothelial of signaling proteins in J. 2000; Scholar). These findings were from of a M. for lipid rafts in interleukin-2 receptor 2001; which that IL-2Rα enriched in lipid rafts and that the IL-2Rβ and were found in detergent-soluble results that DHA treatment and displacement from membrane lipid rafts. The IL-2R from lipid rafts to membrane fractions were important for the of the IL-2R signaling The Janus family kinases and JAK3 kinases and in response to IL-2 were not detected in lipid rafts but in membrane fractions with a J. A. G. and signaling of the interleukin-2 receptor in human T cell J. Scholar). data are for the of PUFAs on the signaling of receptors and in rafts H. H. the and of transcription pathway in endothelial of signaling proteins in J. 2000; Scholar, J. L. of and receptor in membrane rafts of human T Leukoc. Biol. 2000; Scholar). Some results have indicated that were detected in rafts, enriched in detergent-soluble H. H. the and of transcription pathway in endothelial of signaling proteins in J. 2000; Scholar). to the of signaling upon IL-2-induced receptor are to the of the plasma membrane receptor and by family and to the to modulate of that the of with plasma membrane rafts from docosahexaenoic acid suppresses T cell protein lipid raft and IL-2 Immunol. Scholar, I. G. L. signaling through the J. 1998; 334: Scholar, and 1997; Scholar, J.J. and Immunol. 1998; Scholar, and activation in response to and signaling Scholar, M. V. signaling. in plasma membrane rafts.J. Biol. Chem. Scholar). However, in and M. P. receptor is associated with the components of the signaling pathway and to activation of this pathway upon receptor in the human cell Biol. Chem. 1997; Scholar) first found of the in a detergent-resistant of human cells. and were also in this of cell membrane M. V. signaling. in plasma membrane rafts.J. Biol. Chem. which the of signaling in cell membrane rafts and in Scholar). in this detected the presence of STAT5a and STAT5b not in detergent-soluble fractions but also in detergent-resistant rafts. DHA treatment, STAT5a and STAT5b were not detected in lipid raft fractions but were located in detergent-soluble fractions. the results in that associated with detergent-soluble fractions and with DHA We that in membrane rafts be a in signaling and that membrane rafts for the effects of and activation of the alteration of in rafts an of the subcellular distribution of our data demonstrate that altered raft lipid the membrane subdomain distribution of proteins in the IL-2R signaling pathway in T-cells. in lipid rafts by DHA treatment the function and immunomodulatory However, the PUFA treatment in in in a by the in and by from in The are for the for