title: Tyrosine phosphorylation induced by cross-linking of Fc gamma-receptor type II in human neutrophils.
abstract: Neutrophils express several receptors for the Fc region of IgG molecules. Specific cross-linking of the type II receptor (Fc gamma RII) can be achieved by treating neutrophils with the Fab fragment of a specific monoclonal antibody IV.3 against the receptor followed by goat anti-mouse IgG F(ab')2 fragment. Such treatment initiates a number of neutrophil responses including the release of O2-. and increased protein tyrosine phosphorylation. The increase in tyrosine phosphorylation is rapid and transient and correlates with O2-. release. Both responses are inhibited by pretreatment of neutrophils with a protein tyrosine kinase inhibitor, genistein. The increase in protein tyrosine phosphorylation is not inhibited by pretreatment of neutrophils with pertussis toxin or an intracellular Ca2+ chelator, but is enhanced by a phosphoprotein phosphatase inhibitor, okadaic acid. The activity of a neutrophil Ca2+/calmodulin-dependent protein kinase II (CAMPKII) is also stimulated by cross-linking Fc gamma RII. The increase in CAMPKII activity is inhibited by pretreatment with either genistein or Ca2+ chelator. The results suggest that the increase in protein tyrosine phosphorylation induced by cross-linking of Fc gamma RII requires neither pertussis-toxin-sensitive G-proteins nor a rise in intracellular Ca2+ but can be regulated by protein phosphatases. Furthermore, protein tyrosine phosphorylation may be an early signal functionally linked to Fc gamma RII-mediated signal transduction leading to CAMPKII activation and O2-. release in human neutrophils.
authors.affiliation: Department of Pathology, University of Connecticut Health Center, Farmington 06030.
authors.forename: L
authors.initials: L
authors.lastname: Liang
authors.forename: C K
authors.initials: CK
authors.lastname: Huang
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D003432:Cross-Linking Reagents; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004988:Ethers, Cyclic / Q000494:pharmacology; D019833:Genistein; D006801:Humans; D007529:Isoflavones / Q000494:pharmacology; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000378:metabolism*; D019319:Okadaic Acid; D037342:Pertussis Toxin; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D017452:Receptors, IgG / Q000276:immunology / Q000502:physiology*; D016897:Respiratory Burst; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D003432:Cross-Linking Reagents; D004988:Ethers, Cyclic; D007529:Isoflavones; D010750:Phosphoproteins; D017452:Receptors, IgG; D010566:Virulence Factors, Bordetella; D019319:Okadaic Acid; D019000:Phosphotyrosine; D014443:Tyrosine; D004533:Egtazic Acid; D019833:Genistein; D037342:Pertussis Toxin; D011505:Protein-Tyrosine Kinases; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid