title: Induction of FMLP-mediated calcium mobilization requires crosslinking of surface immunoglobulin in Daudi cells.
abstract: We have explored the requirements for the induction of the N-formyl-methionyl-leucyl-phenylalanine (FMLP) response in Daudi cells after anti-immunoglobulin treatment. Our results indicate that (a) induction of responsiveness to FMLP was observed in Daudi only after crosslinking of surface immunoglobulin by anti-immunoglobulin; (b) this induced responsiveness was not observed in Ramos or Wil-2 cells; (c) the F(ab')2 fragment was sufficient for the induction of the FMLP response, but the Fab fragment and the Fc fragment were ineffective; (d) of the many agents active in B lymphocyte regulation which were tested, none were as effective as anti-immunoglobulin in the induction of the FMLP response; and (e) three inhibitors of calcium mobilization (W-7 (N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide), PMA (phorbol 12-myristate 13-acetate), and colchicine), acting on distinct mechanisms, inhibited both the calcium mobilization due to anti-immunoglobulin and the induction of responsiveness to FMLP. Our results suggest important determinants in the induction of a calcium-mobilizing FMLP response in cells of B lymphocyte lineage include (a) the cell type, (b) a selective requirement for activation via surface immunoglobulin, and (c) crosslinking of the surface immunoglobulin.
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: S J
authors.initials: SJ
authors.lastname: Scott
authors.forename: C K
authors.initials: CK
authors.lastname: Lin
authors.forename: D G
authors.initials: DG
authors.lastname: Gu
authors.forename: P M
authors.initials: PM
authors.lastname: Lad
mesh_terms: D000906:Antibodies; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line / Q000187:drug effects; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry / Q000378:metabolism*; D007136:Immunoglobulins / Q000737:chemistry; D008565:Membrane Proteins / Q000378:metabolism; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D015398:Signal Transduction
chemical_list: D000906:Antibodies; D007140:Immunoglobulin Fab Fragments; D007136:Immunoglobulins; D008565:Membrane Proteins; D009240:N-Formylmethionine Leucyl-Phenylalanine; D002118:Calcium