Analysis of subcellular calcium signals in T-lymphocytes.
Subcellular Ca(2+) signals were analysed in Jurkat and peripheral human T-lymphocytes by confocal Ca(2+) imaging employing an off-line deconvolution method. Stimulation of the TCR/CD3 complex in T-lymphocytes resulted in a series of subcellular pacemaker Ca(2+) signals preceding the first global Ca(2+) signal. The pacemaker signals occurred in a cytosolic "trigger" zone, which is localised close to the plasma membrane. The pacemaker signals were almost independent of extracellular Ca(2+) as shown by measurements in the absence of extracellular Ca(2+), or in the presence of the Ca(2+) channel blocker SK-F 96365. Analysis of the confocal Ca(2+) images revealed characteristic amplitudes of 82 +/- 30 to 109 +/- 21 nM, signal diameters between 2.5 +/- 0.9 and 3.5 +/- 1.5 microm and frequencies between 0.235 and 0.677 s(-1). Taken together, our data constitute the first analysis of subcellular Ca(2+) signals in T cells and indicate that the pacemaker Ca(2+) release events, which are necessary for the development of the global Ca(2+) signal, are composed of Ca(2+) release both from inositol 1,4,5-trisphosphate- and ryanodine receptors.
Kunerth
Svenja
S
Center for Theoretical Medicine, Institute for Biochemistry and Molecular Biology I: University Hospital Hamburg-Eppendorf, D-20246 Hamburg, Germany.
Mayr
Georg W
GW
Koch-Nolte
Friedrich
F
Guse
Andreas H
AH
D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D053496:Inositol 1,4,5-Trisphosphate Receptors; D019169:Jurkat Cells; D018613:Microscopy, Confocal; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000819:agonists / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000187:drug effects / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000187:drug effects / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*
D002121:Calcium Channel Blockers; D015220:Calcium Channels; C506926:ITPR1 protein, human; D053496:Inositol 1,4,5-Trisphosphate Receptors; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D018160:Receptors, Cytoplasmic and Nuclear; D019837:Ryanodine Receptor Calcium Release Channel; D002118:Calcium