Integrin-mediated intracellular Ca2+ signaling in Jurkat T lymphocytes.
T lymphocytes interact with components of the extracellular matrix after transendothelial migration on their way to sites of inflammation. To characterize the molecular basis of the interaction between T lymphocytes with different extracellular matrix proteins, we investigated the role of intracellular Ca2+ as a signal mediating such interactions and identified the cell surface integrins involved in this process. When Jurkat T lymphocytes loaded with the calcium-sensitive fluorescent dye fura-2 were placed on coverslips coated with human fibronectin, human collagen types I, IV, and VI, human tenascin, human laminin I, or mouse laminin I, an elevation in intracellular Ca2+ concentration was observed. In contrast, contact of the Jurkat T lymphocytes with vitronectin and thrombospondin did not induce Ca2+ signals in more cells as compared with control measurements in which cells were in contact with only BSA or polylysine. Furthermore, the percentage of Jurkat T lymphocytes responding with Ca2+ signals to collagen types I and IV, fibronectin, and laminin I was completely reduced to levels observed on BSA or polylysine when the cells were pretreated with specific anti-integrin Abs, suggesting a role for cell surface integrins as mediators of cell matrix-induced intracellular Ca2+ signaling. Similar results were obtained with peripheral human T lymphocytes activated by phytohemagglutinin.
Weismann
M
M
University of Hamburg, Institute of Physiological Chemistry, Department of Enzyme Chemistry, Germany.
Guse
A H
AH
Sorokin
L
L
Bröker
B
B
Frieser
M
M
Hallmann
R
R
Mayr
G W
GW
D019138:Antibodies, Blocking / Q000494:pharmacology; D002118:Calcium / Q000276:immunology / Q000378:metabolism*; D002450:Cell Communication / Q000276:immunology; D006801:Humans; D016023:Integrins / Q000276:immunology / Q000502:physiology*; D007424:Intracellular Fluid / Q000276:immunology / Q000378:metabolism; D019169:Jurkat Cells; D008213:Lymphocyte Activation / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology*; D013601:T-Lymphocytes / Q000378:metabolism*; D019699:Thrombospondins; D019096:Vitronectin / Q000502:physiology
D019138:Antibodies, Blocking; D016023:Integrins; D008562:Membrane Glycoproteins; D019699:Thrombospondins; D019096:Vitronectin; D002118:Calcium