Membrane lipid microdomains and the role of PKCtheta in T cell activation.
Productive T cell activation depends on the assembly of a highly ordered and compartmentalized immunological synapse or supramolecular activation complex (SMAC). Reorganization of the actin cytoskeleton and clustering of specialized membrane microdomains, or lipid rafts, occur early following TCR/CD3 and costimulatory receptor ligation. Many key signaling molecules localize in lipid raft patches during T cell activation. Lipid raft reorganization is required for T cell activation, where it plays an apparently important role in stabilizing the T cell synapse. Here we review recent evidence supporting the role of lipid rafts in T cell activation. Particular emphasis is placed on the coupling of protein kinase C-theta(PKCtheta), which is selectively expressed in T cells and is known to function as an essential signal for T cell activation, and lipid rafts.
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K
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Division of Cell Biology, La Jolla Institute for Allergy and Immunology, San Diego, CA 92121, USA.
Altman
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D000818:Animals; D003599:Cytoskeleton / Q000502:physiology; D006801:Humans; D007527:Isoenzymes / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D021962:Membrane Microdomains / Q000276:immunology*; D011493:Protein Kinase C / Q000276:immunology*; D000074121:Protein Kinase C-theta; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D007527:Isoenzymes; D011948:Receptors, Antigen, T-Cell; C076233:PRKCQ protein, human; D011493:Protein Kinase C; D000074121:Protein Kinase C-theta