Interleukin 2 rapidly stimulates synthesis and breakdown of polyphosphoinositides in interleukin 2-dependent, murine T-cell lines.
Several T-cell functions are controlled by the regulatory peptide interleukin 2 (IL-2). Binding of IL-2 with specific receptors has been well documented, but the molecular mechanism by which IL-2/IL-2 receptor interaction is transduced is not known. We have found that treatment of IL-2-dependent T-cell lines with IL-2 is followed by a rapid stimulation of inositol phospholipid metabolism, as determined by isotopic methodology employing myo-[1,2-3H]inositol. Increased incorporation of the metabolic precursor into phosphatidylinositol and phosphatidylinositol 4-monophosphate, together with the appearance of radiolabeled phosphatidylinositol 4,5-bisphosphate, occurred within minutes of treatment with IL-2 of factor-dependent CT6 cells. Analysis of labeled water-soluble compounds from prelabeled cells indicated a rapid (within 1 min) stimulation of inositol phospholipid hydrolysis following IL-2 treatment. Increased recovery of [3H] inositol phosphates and appearance of [3H]inositol trisphosphate were observed after treatment with IL-2 of CT6 cells, as well as of a second IL-2-dependent cell line, CTB6. These findings suggests that inositol phospholipid-derived metabolites (i.e. diacylglycerol and inositol trisphosphate) may be part of the mechanism by which certain IL-2 signals are transduced.
D000818:Animals; D002460:Cell Line; D004075:Diglycerides / Q000378:metabolism; D007294:Inositol / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000378:metabolism; D007376:Interleukin-2 / Q000502:physiology*; D007700:Kinetics; D051379:Mice; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism*
D004075:Diglycerides; D007295:Inositol Phosphates; D007376:Interleukin-2; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; C037178:phosphatidylinositol 4-phosphate; D007294:Inositol; D015544:Inositol 1,4,5-Trisphosphate