Spatial and temporal characteristics of the increase in intracellular Ca2+ induced in cytotoxic T lymphocytes by cellular antigen.
The increase in intracellular Ca2+ concentration [( Ca2+]i) in cytolytic T lymphocytes in response to target cell binding was investigated by ratio image fluorescence microscopy. Ca2+ mobilization from intracellular stores occurred at a site distal to target cell contact and was transient. Extracellular Ca2+ influx resulted in an increase in [Ca2+]i that was prolonged and distributed more proximal to the target cell. Oscillations in [Ca2+]i were observed after target cell contact, although the periodicity was dependent on the presence of extracellular Ca2+. The Ag-specific reorientation of cytoplasmic granules occurred well after [Ca2+]i had begun to decline to a resting level, but was dependent on extracellular Ca2+. These studies indicate that the Ag-stimulated increase in [Ca2+]i exhibits considerable spatial and temporal variation, and that these characteristics are altered by the availability of extracellular Ca2+. The results also suggest that these changes in [Ca2+]i may play a role in the cytoplasmic events that accompany T cell-mediated cytolysis.
Gray
L S
LS
Department of Pathology, University of Virginia School of Medicine, Charlottesville 22908.
Gnarra
J R
JR
Sullivan
J A
JA
Mandell
G L
GL
Engelhard
V H
VH
D000818:Animals; D001826:Body Fluids / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism* / Q000502:physiology; D002450:Cell Communication; D003594:Cytoplasmic Granules / Q000378:metabolism; D003601:Cytotoxicity Tests, Immunologic; D005110:Extracellular Space / Q000502:physiology; D015234:HLA-A Antigens / Q000276:immunology; D015789:HLA-A2 Antigen; D007424:Intracellular Fluid / Q000378:metabolism*; D007700:Kinetics; D008213:Lymphocyte Activation; D051379:Mice; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism* / Q000502:physiology
D015234:HLA-A Antigens; D015789:HLA-A2 Antigen; D002118:Calcium