title: Antigen-specific IgG and IgA, but not IgE, activate the effector functions of eosinophils in the presence of antigen.
abstract: BACKGROUND
  Activated eosinophils are thought to play an important role in allergic inflammation. Prior reports suggest that eosinophils have receptors recognizing IgA, IgG and IgE; however, little is known regarding the direct effects of antigens and antigen-specific immunoglobulins on the functions of eosinophils.
  
  
  METHODS
  To investigate eosinophil activation by antigens mediated by the various antigen-specific immunoglobulins, we used dansyl-conjugated bovine serum albumin (DNS-BSA) and recombinant dansyl-specific antibodies (human IgG 1-4, IgA and IgE). Eosinophils from healthy donors were incubated in the wells coated with dansyl-specific immunoglobulins with or without DNS-BSA. Eosinophil activation was monitored by superoxide production and eosinophil-derived neurotoxin (EDN) release.
  
  
  RESULTS
  Superoxide production and EDN release by eosinophils were induced by the dansyl-specific reaction via all IgG subclasses (IgG 1-4) and IgA in the presence of DNS-BSA; the responses were not observed in the absence of antigen, DNS-BSA. The immune complexes (ICs) of DNS-BSA and dansyl-specific IgE did not induce these responses. Furthermore, IgE ICs did not enhance eosinophil activation stimulated with various immunoglobulins, IL-5 or platelet-activating factor.
  
  
  CONCLUSIONS
  These data suggest that ICs of antigens and antigen-specific IgGs and IgA, but not IgE, in inflamed tissues may activate eosinophils and play an important role in allergic inflammation.
authors: Division of Allergic Diseases and Department of Medicine, Mayo Clinic Rochester, Rochester, Minn., USA. muraki@ko-arena.med.kindai.ac.jp
authors: Masato
authors: M
authors: Muraki
authors: Gerald J
authors: GJ
authors: Gleich
authors: Hirohito
authors: H
authors: Kita
mesh_terms: D000936:Antigen-Antibody Complex / Q000276:immunology*; D003619:Dansyl Compounds / Q000494:pharmacology; D047208:Eosinophil-Derived Neurotoxin / Q000276:immunology; D004804:Eosinophils / Q000276:immunology*; D000939:Epitopes; D006632:Histamine / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007073:Immunoglobulin E / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D012710:Serum Albumin, Bovine / Q000276:immunology*; D018709:Statistics, Nonparametric; D013481:Superoxides / Q000276:immunology
chemical_list: D000936:Antigen-Antibody Complex; D003619:Dansyl Compounds; D000939:Epitopes; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D013481:Superoxides; D012710:Serum Albumin, Bovine; D007073:Immunoglobulin E; D006632:Histamine; D047208:Eosinophil-Derived Neurotoxin