title: Anti-immunoglobulin pretreatment induces a calcium-mobilization response to the chemotactic agent N-formylmethionylleucylphenylalanine in Daudi lymphoblastoid cells.
abstract: Anti-immunoglobulin treatment of fura-2-loaded Daudi cells induces a calcium mobilization as judged by the increase in the fluorescence of the dye fura-2, AM. No calcium mobilization by N-fMet-Leu-Phe is observed in these cells. However, exposure of the cells to N-fMet-Leu-Phe after the first hit with anti-immunoglobulin (but not after soluble IgG) shows a rapid, dose-dependent calcium mobilization by N-fMet-Leu-Phe. The expression of the calcium-mobilizing response occurs in less than 2 min and is stable. Binding of tritiated N-fMet-Leu-Phe is increased in anti-immunoglobulin-treated but not control cells. The induction is specific for N-fMet-Leu-Phe because the chemoattractant platelet-activating factor did not induce any calcium mobilization. The N-fMet-Leu-Phe antagonist t-butoxycarbonyl-L-Phe-D-Leu-L-Phe-D-Leu-L-Phe- OH did not show any calcium mobilization on its own, either before or after anti-immunoglobulin treatment, and inhibited the calcium mobilization of N-fMet-Leu-Phe at low concentrations. Treatment of the cells with phorbol 12-myristate 13-acetate or pertussis toxin prior to anti-immunoglobulin treatment caused a dose-dependent abolition of both the anti-immunoglobulin-mediated calcium mobilization and the subsequent calcium mobilization by N-fMet-Leu-Phe. Metabolic inhibitors that act predominantly by lowering the ATP levels within the cell (iodoacetate, sodium fluoride, oligomycin, and 2-deoxyglucose) all produced a greater inhibition of the N-fMet-Leu-Phe-mediated calcium mobilization than the anti-immunoglobulin-mediated response. Lowering the temperature from 37 degrees C to 22 degrees C reduced the anti-immunoglobulin response and completely inhibited the expression of the N-fMet-Leu-Phe effect. Our results indicate that activation of the calcium-mobilization pathway in B cells by crosslinking of bound surface immunoglobulin causes an induction of N-fMet-Leu-Phe-sensitive calcium mobilization.
authors.affiliation: Regional Research Laboratory, Kaiser Permanente Medical Center, Los Angeles, CA 90027.
authors.forename: C I
authors.initials: CI
authors.lastname: Kalunta
authors.forename: J S
authors.initials: JS
authors.lastname: Kaptein
authors.forename: H
authors.initials: H
authors.lastname: Niedzin
authors.forename: S J
authors.initials: SJ
authors.lastname: Scott
authors.forename: G H
authors.initials: GH
authors.lastname: Lee
authors.forename: P M
authors.initials: PM
authors.lastname: Lad
mesh_terms: D000936:Antigen-Antibody Complex; D001572:Benzofurans; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D016257:Fura-2; D006801:Humans; D007074:Immunoglobulin G; D007700:Kinetics; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000936:Antigen-Antibody Complex; D001572:Benzofurans; D007074:Immunoglobulin G; D009240:N-Formylmethionine Leucyl-Phenylalanine; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium; D016257:Fura-2