Lipid Rafts & Co.: An integrated model of membrane organization in T cell activation

Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna, Vienna, Austria.
Progress in Lipid Research (Impact Factor: 10.02). 06/2006; 45(3):187-202. DOI: 10.1016/j.plipres.2006.01.002
Source: PubMed


The model of membrane compartmentalization by self-organizing functional lipid microdomains, named lipid rafts, has been a fruitful concept resulting in great progress in understanding T cell signal transduction. However, due to recent results it has become clear that lipid rafts describe only one out of several membrane organizing principles crucial for T cell activation besides fences and pickets and protein-protein interactions that take part in the formation of the immunological synapse as a highly organized structure at the T cell contact site to the antigen-presenting cell. This review describes the concepts of lipid rafts and other membrane organizing principles to evolve a novel integrated model on the functional role of microdomains in immunological synapse formation and T cell activation. Further research has to elucidate the relative contribution and interrelation of different modes of membrane organization in productive T cell activation.

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    • "The function of the lipid raft is correlated to its cholesterol content and the removal of cholesterol from these micro-domains can interfere with signaling pathways in immune cells,[49] and with antigen-presenting function.[50] One main function of lipid rafts is the regulation of signaling through the T cell receptors.[51]–[53] As an example, the localization of major histocompatibility (MHC) class II molecules in lipid rafts[54]–[56] facilitate the function of antigen-presenting cells and is essential for T cell activation, as this process decreases the amount of antigen necessary for T cell activation.[57],[58] "
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    • "Cholesterol-rich microdomains known as lipid rafts are postulated to be a driving force in immunological synapse formation and critical for T-cell signaling [1], [59]–[61]. "
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