Quantifying signaling-induced reorientation of T cell receptors during immunological synapse formation.
Productive T cell recognition of antigen-presenting cells (APCs) is normally accompanied by the formation of a cell-cell contact called the "immunological synapse." Our understanding of the steps leading up to this formation has been limited by the absence of tools for analyzing 3D surfaces and surface distributions as they change over time. Here we use a 3D fluorescence quantitation method to show that T cell receptors are recruited in bulk within the first minute after the onset of activation and with velocities ranging from 0.04 to 0.1 microm/s; a speed significantly greater than unrestricted diffusion. Our method reveals a second feature of this reorientation: a conformational change as the T cell pushes more total membrane into the interface creating a larger contact area for additional receptors. Analysis of individual T cell receptor velocities using a single-particle tracking method confirms our velocity measurement. This method should permit the quantitation of other dynamic membrane events and the associated movement of cell-surface molecules.
Moss
William C
WC
Department of Microbiology and Immunology, Stanford University School of Medicine and Howard Hughes Medical Institute, CA 94305, USA.
Irvine
Darrell J
DJ
Davis
Mark M
MM
Krummel
Matthew F
MF
D000818:Animals; D017252:CD3 Complex / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology; D002465:Cell Movement; D016764:Cell Polarity; D002999:Clone Cells; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D008213:Lymphocyte Activation; D051379:Mice; D008806:Mice, Inbred AKR; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D015398:Signal Transduction / Q000276:immunology*; D013569:Synapses / Q000276:immunology / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000502:physiology; D014162:Transfection
D017252:CD3 Complex; C121704:CD3 antigen, zeta chain; D008164:Luminescent Proteins; D011948:Receptors, Antigen, T-Cell; D049452:Green Fluorescent Proteins