T-cell chemiluminescence. A novel aspect of T-cell membrane activation studied with a Jurkat tumour cell line.
The binding of mitogenic lectins phytohaemagglutinin (PHA), concanavalin A (Con A) and/or of monoclonal antibodies to different receptors such as antigen receptor complex or CD2 on human T cells generates increases in the concentrations of inositol triphosphate (IP3) and cytoplasmic free calcium. This T lymphocyte requires the delivery of two signals; the first can be provided by specific monoclonal antibodies or by mitogenic lectins, and the second by a phorbol ester, phorbol myristate acetate (PMA). In other cells such as macrophages, the rise of intracellular calcium via the generation of IP3 and stimulation of protein kinase C can activate the phospholipase A2, a calcium-dependent enzyme. This enzyme initiates the release of reactive oxygen intermediates and metabolites of arachidonic acid. In order to know whether this other metabolic pathway can be generated in T cells, we tested the capacity of different T-cell lines and clones to produce superoxide anion after stimulation by the above-mentioned activating agents. In this paper, we demonstrate that treatment of the Jurkat human cell line with Con A, PHA, and PMA results in a significant release of reactive oxygen metabolites. Of the various T-cell lines and clones tested, only Jurkat exhibited an oxidative burst. Moreover, none of the antibodies tested (anti-CD3, anti-CD2, and anti-CD28) and known to activate T cells, and none of the immune complexes was able to mediate such an effect. The existence of an oxidative metabolism in at least one T-cell line suggests that T-cell activation may in some instances use another metabolic pathway.
Benichou
G
G
Claude Bernard Research Centre, Pasteur Institute, Paris, France.
Kanellopoulos
J M
JM
Mitenne
F
F
Galanaud
P
P
Leca
G
G
D005609:Free Radicals; D006801:Humans; D037102:Lectins / Q000494:pharmacology; D015458:Leukemia, T-Cell / Q000378:metabolism; D008163:Luminescent Measurements; D008213:Lymphocyte Activation; D010100:Oxygen / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D005609:Free Radicals; D037102:Lectins; D013755:Tetradecanoylphorbol Acetate; D010100:Oxygen