Functional expression of the murine Thy-1.2 gene in transfected human T cells.
The interaction of certain mAbs with the Thy-1 molecules of murine T lymphocytes leads to cell activation and proliferation. To examine the signal transduction mechanism underlying this process and to determine what, if any, relationship exists between Thy-1-dependent triggering and T cell activation mediated through the T3-antigen receptor (T3-Ti) complex, a genomic clone of murine Thy-1.2 was isolated and transfected into the human T cell tumor, Jurkat. The transfected gene was actively transcribed in these human cells and high levels of Thy-1.2 glycoprotein were found on the cell membrane. Although certain mAbs to Thy-1.2 failed to bind to the Thy-1 transfected Jurkat cells, several known mitogenic anti-Thy-1 mAbs did react, and in the presence of phorbol ester, induced IL-2 secretion. One Thy-1+ transfectant out of five failed to produce IL-2 in response to anti-T3/Ti antibodies even though it retained the ability to increase intracytoplasmic calcium concentration [( Ca2+]i) in response to these ligands. A Thy-1 negative revertant of this cell regained anti-T3/Ti reactivity, suggesting a regulatory defect in signal transmission via T3/Ti in the original transfectant. These data confirm the ability of Thy-1 to act as an activation receptor for T cells. They reveal a potential role for changes in [Ca2+]i in this process, in common with other pathways of T cell activation, but also indicate a more complex series of events is involved.
Gunter
K C
KC
Kroczek
R A
RA
Shevach
E M
EM
Germain
R N
RN
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000235:genetics / Q000502:physiology*; D002051:Burkitt Lymphoma; D002460:Cell Line; D000939:Epitopes / Q000276:immunology; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D007518:Isoantibodies / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018800:Thy-1 Antigens; D014162:Transfection
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D000939:Epitopes; D007376:Interleukin-2; D007518:Isoantibodies; D018800:Thy-1 Antigens; C035678:anti-Thy antibody; D013755:Tetradecanoylphorbol Acetate