title: Regulation of IL 3 expression by glucocorticoids in cloned murine T lymphocytes.
abstract: We have examined the effects of glucocorticoids on the concanavalin A (Con A)-stimulated production of interleukin 3 (IL 3) by a murine helper T cell clone Cl.Ly-1+2-/9. The addition of Con A to Cl.Ly-1+2-/9 cells leads to the rapid induction of both IL 3 mRNA and activity. A synthetic glucocorticoid, dexamethasone, inhibits the appearance of IL 3 activity in the supernatants of Con A-stimulated cells, as well as the accumulation of IL 3 mRNA in the cells. A similar effect is observed with other Con A-inducible mRNA, such as the mRNA encoding granulocyte-macrophage colony-stimulating factor (GM-CSF), but the hormone effects are not general; the constitutive synthesis of Thy-1 mRNA is not altered by dexamethasone treatment. Several lines of evidence suggest that dexamethasone directly inhibits transcription of the IL 3 gene: the kinetics of dexamethasone action on IL 3 mRNA are rapid; the stability of IL 3 mRNA is not affected by dexamethasone; hormone treatment does not inhibit either mRNA processing or transport from the nucleus. Our findings demonstrate that a set of mitogen-inducible genes in helper T cells can be subject to a second level of regulation mediated by glucocorticoid hormones.
authors.forename: J A
authors.initials: JA
authors.lastname: Culpepper
authors.forename: F
authors.initials: F
authors.lastname: Lee
mesh_terms: D000818:Animals; D002999:Clone Cells / Q000276:immunology / Q000378:metabolism; D003208:Concanavalin A / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007377:Interleukin-3; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000096:biosynthesis / Q000378:metabolism*; D008407:Mast Cells / Q000166:cytology; D051379:Mice; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D007166:Immunosuppressive Agents; D007377:Interleukin-3; D008222:Lymphokines; D012333:RNA, Messenger; D003208:Concanavalin A; D003907:Dexamethasone