Lymphocytes Adhesion Molecules on Human T Redistribution of Antigen
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Lipid Microdomain Clustering Induces a Redistribution of Antigen Recognition and Adhesion Molecules on Human T Lymphocytes This information is current as of September 26, 2021. Jason S. Mitchell, Oguz Kanca and Bradley W. McIntyre J Immunol 2002; 168:2737-2744; ; doi: 10.4049/jimmunol.168.6.2737 http://www.jimmunol.org/content/168/6/2737 Downloaded from References This article cites 45 articles, 27 of which you can access for free at: http://www.jimmunol.org/content/168/6/2737.full#ref-list-1 http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication by guest on September 26, 2021 *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2002 by The American Association of Immunologists All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. Lipid Microdomain Clustering Induces a Redistribution of Antigen Recognition and Adhesion Molecules on Human T Lymphocytes1 Jason S. Mitchell, Oguz Kanca, and Bradley W. McIntyre2 The study of lipid microdomains in the plasma membrane is a topic of recent interest in leukocyte biology. Many T cell activation and signaling molecules are found to be associated with lipid microdomains and have been implicated in normal T cell function. It has been proposed that lipid microdomains with their associated molecules move by lateral diffusion to areas of cellular  interactions to initiate signaling pathways. Using sucrose density gradients we have found that human T cell 1 integrins are not normally associated with lipid microdomains. However, cross-linking of GM1 through cholera toxin B-subunit (CTB) causes an  enrichment of 1 integrins in microdomain fractions, suggesting that cross-linking lipid microdomains causes a reorganization of Downloaded from molecular associations. Fluorescent microscopy was used to examine the localization of various lymphocyte surface molecules before and after lipid microdomain cross-linking. Lymphocytes treated with FITC-CTB reveal an endocytic vesicle that is en-  riched in TCR and CD59, while 1 integrin, CD43, and LFA-3 were not localized in the vesicle. However, when anti-CTB Abs are used to cross-link lipid microdomains, the microdomains are not internalized but are clustered on the cell surface. In this study,  CD59, CD43, and 1 integrin are all seen to colocalize in a new lipid microdomain from which LFA-3 remains excluded and the TCR is now dissociated. These findings show that cross-linking lipid microdomains can cause a dynamic rearrangement of the http://www.jimmunol.org/ normal order of T lymphocyte microdomains into an organization where novel associations are created and signaling pathways may be initiated. The Journal of Immunology, 2002, 168: 2737–2744. he lymphocyte cell surface membrane consists of micro- as Ras, Lck, Grb-2, phosphatidylinositol-3 kinase, and Fyn (2, scopically and biochemically distinguishable lipid mi- 4–7). Lipid rafts/microdomains are also believed to have a func- T crodomains that result from the assembly of sphingolipids tional significance, because cells with cholesterol depleted from and cholesterol into laterally mobile rafts (1, 2). Sphingolipids lipid microdomains have decreased levels of basal adhesion and contain predominately large, saturated acyl chains that allow them decreased CD3-induced TCR phosphorylation (8, 9). Further- to pack tightly together. Furthermore, phase separations between more, lipid raft/microdomain patching can induce Ca2ϩ flux, by guest on September 26, 2021 lipid microdomains and loosely ordered membrane glycerophos- Z-chain associated-70 kDa protein/linker for activation of T cells/ pholipids give lipid microdomains a high degree of lateral mobility extracellular signal-regulated kinase-2 phosphorylation, and within the membrane (3). These lipid microdomains are also NFAT stimulation (10). The partitioning of these signaling mole- known as lipid rafts or glycolipid-enriched membrane domains cules to laterally mobile sphingolipids has been proposed as a and, due to their insolubility in nonionic mild detergents, they are means for signaling molecules to specifically “traffic” to areas of also called detergent-insoluble glycolipid-enriched domains receptor engagement and initiate a variety of different signaling (DIGs)3 or detergent-resistant membranes (4). Lipid microdomains pathways (1, 3). have a low density, and sucrose gradient ultracentrifugation of Lipid microdomains can be detected with the B-subunit of chol- mild detergent cell lysates can isolate these microdomains into era toxin (CTB), the membrane-binding subunit that binds a major low-density fractions along with the molecules that are associated component of lipid rafts, GM1 gangliosides (11, 12). Costimula- with them. Western blot analysis of these low-density fractions has tion of naive T lymphocytes with anti-CD3 and anti-CD28 beads revealed the presence of many GPI-anchored proteins, such as results in redistribution of GM1 lipids from a diffuse distribution to Thy-1, Ly-6, and CD59, and intracellular signaling proteins such a concentration at the bead contact site, as visualized by FITC- CTB. It was also determined that cross-linking GPI-anchored CD59, a raft/microdomain-associated lymphocyte surface protein, Department of Immunology, University of Texas, M. D. Anderson Cancer Center, or, more importantly, cross-linking of GM1 directly with immo- Houston, TX 77030 bilized CTB provided efficient T cell costimulation (13). The im- Received for publication July 10, 2001. Accepted for publication January 14, 2002. plication of these studies was that costimulation is mediated by The costs of publication of this article were defrayed in part by the payment of page lipid microdomains. Furthermore, the integrin LFA-1 was shown charges. This article must therefore be hereby marked advertisement in accordance to colocalize to membrane rafts/microdomains, and high-avidity with 18 U.S.C. Section 1734 solely to indicate this fact. adhesion could be induced by clustering these membrane microdo- 1 This work was supported by National Institutes of Health Grant CA62596 and Predoctoral Cancer Immunobiology Training Program Grant CA09598. mains (8). Therefore, lipid microdomains may also regulate lym- 2 Address correspondence and reprint requests to Dr. Bradley W. McIntyre, Depart- phocyte intercellular interactions needed for efficient adhesion to ment of Immunology University of Texas, M. D. Anderson Cancer Center, 1515 APCs during immune recognition or for adhesion to endothelial Holcombe Boulevard, Box 180, Houston, TX 77030. E-mail address: bmcintyr@ cells to mediate lymphocyte migration and recirculation. The bio- mail.mdanderson.org chemical evidence available so far has substantially implicated 3 Abbreviations used in this paper: DIG, detergent-insoluble glycolipid-enriched do- main; CTB, cholera toxin B-subunit; HPB-ALL, human peripheral blood acute lym- lipid rafts/microdomains in the normal function of T cells (14–16). phocytic leukemia; IODO-GEN, 1,3,4,6-tetrachloro-3␣,6␣,diphenylglycoluril. However, the information from this type of analysis may be Copyright © 2002 by The American Association of Immunologists 0022-1767/02/$02.00 2738 REORGANIZATION OF LYMPHOCYTE SURFACE MICRODOMAINS limited because the use of detergents in these experiments may sucrose gradients and the collected fractions were immunoprecipitated with  partially solubilize some lipid microdomains even at low temper- protein G-agarose beads (Pierce) precomplexed with the anti- 1 integrin atures, disrupting low-affinity interactions and transient associa- mAb 18D3. Polypeptides were eluted by boiling in reducing Laemmli sam- ple buffer and separated by 7.5% SDS-PAGE. Dried gels were exposed to tions (3, 15). Because lipid microdomain trafficking is based on Kodak XR film (Kodak, Rochester, NY) at Ϫ80°C. molecular compartmentalization, fluorescence microscopy has be- come an invaluable tool to visualize lipid microdomain associa- Fluorescence staining and image analysis tions and movements. In this paper we have investigated the spatial In the GM1 internalization experiments, HPB-ALL T cells were stained in relationships of various T cell adhesion and activation molecules complete RPMI 1640 medium with FITC-conjugated CTB (Sigma-Al- in the context of Ab cross-linking of GM1 lipid microdomains. drich) at 25 g/ml for1hat37°C. The cells were then washed twice with Using CTB to follow lipid microdomains and specific fluorescent complete medium, fixed for 45 min with 4% paraformaldehyde, perme- abilized gently with 0.1% Triton X-100 (Sigma-Aldrich) in PBS for 5 min, mAbs to follow surface molecules, we have found that clustering and stained with specific monoclonal (10 g/ml) and AlexaFluor 594 goat lipid microdomains at physiological temperatures causes a dy- anti-mouse Abs. Finally, the cells were mounted to glass slides with Pro- namic rearrangement of normal T cell microdomain organization long Antifade reagents (Molecular Probes).