Masato Muraki1, Gerald J Gleich, Hirohito Kita. 1. Division of Allergic Diseases and Department of Medicine, Mayo Clinic Rochester, Rochester, Minn., USA. muraki@ko-arena.med.kindai.ac.jp
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. CONCLUSION: 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.
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 bovineserum 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. CONCLUSION: 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: Shigeharu Ueki; Rossana C N Melo; Ionita Ghiran; Lisa A Spencer; Ann M Dvorak; Peter F Weller Journal: Blood Date: 2013-01-09 Impact factor: 22.113