title: Rosette inhibitory factor (RIF) augments cyclic AMP generation by helper T lymphocytes.
abstract: The effect of Rosette Inhibitory Factor (RIF) on cyclic AMP generation by peripheral blood mononuclear cells (PBMC) and lymphocyte subpopulations (OKT4+ or helper T cells, OKT8+ or suppressor T cells, B lymphocytes) was analyzed. The results were compared to those observed with isoproterenol, an agent which is known to inhibit erythrocyte rosette (ER) formation and increase cyclic AMP levels in T cells. RIF elevated cyclic AMP levels in PBMC, an effect which was observed to be confined to helper T cells. Isoproterenol also elevated levels of cyclic AMP in PBMC but non-selectively augmented levels of the cyclic nucleotide in all lymphocyte subpopulations. Whereas isoproterenol increased cyclic AMP levels within 30 min, RIF did so after a lag period of 4 hr, a delay which is necessary for inhibition of ER formation. These studies reaffirm the selective effect of RIF on helper T cells. We conclude that inhibition of ER formation and possibly other immunoregulatory effects associated with RIF may be mediated via modulation of the adenyl cyclase-cyclic nucleotide network.
mesh_terms: D002469:Cell Separation; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008214:Lymphocytes / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D012397:Rosette Formation; D006377:T-Lymphocytes, Helper-Inducer / Q000502:physiology*
chemical_list: D008077:Lipoproteins, LDL; C022060:rosette-inhibiting factor; D000242:Cyclic AMP; D007545:Isoproterenol