Abstract |
The role of IgG4 antibodies in allergic disorders is suspected. Yet, their presence on human basophil membrane has not been demonstrated and the mechanism of the degranulation induced by anti-IgG4 antibodies remains unclear. As previously reported, we observed that monoclonal anti-IgG4 (10 to 100 micrograms/ml) induced histamine release in the presence of D2O from leukocytes of normal and atopic subjects. The release was accompanied by a decrease of the number of toluidine blue-positive basophils (TB+). Histamine release and TB+ decrease were also observed with lower concentrations of anti-IgG4 (1 to 100 pg/ml). Since basophil activation assessed by TB+ decrease was more sensitive than histamine release, we thus used the former method to further study the mechanisms of the anti-IgG4- vs anti-IgE-induced basophil activation. Basophil activation by anti-IgG4 at 1 to 100 pg/ml, but not by anti-IgG4 at 10 to 100 micrograms/ml or anti-IgE, required the presence of polymorphonuclear cells. Furthermore, anti-IgG4-stimulated purified eosinophils, but not neutrophils, released basophil-activating factors identified as cationic proteins from eosinophils. Thus, the human basophil can be activated by anti-IgG4 via two different mechanisms according to the antibody concentration. At high concentrations (10 to 100 micrograms/ml) basophil activation does not require the presence of polymorphonuclear cells whereas at lower concentrations (1 to 100 pg/ml) the presence of eosinophils is necessary. We propose that in the latter concentration range, basophil activation is a two-step process: 1) release by anti- IgG4 of eosinophil cationic proteins that 2) will, in turn, activate human basophils. This study lends support to the role of IgG4 and eosinophils in anaphylactic reactions.
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Authors | F Beauvais, C Hieblot, C Burtin, J Benveniste |
Journal | Journal of immunology (Baltimore, Md. : 1950)
(J Immunol)
Vol. 144
Issue 10
Pg. 3881-90
(May 15 1990)
ISSN: 0022-1767 [Print] United States |
PMID | 1692064
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Antibodies, Anti-Idiotypic
- Antibodies, Monoclonal
- Immunoglobulin G
- Tolonium Chloride
- Immunoglobulin E
- Calcium
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Topics |
- Antibodies, Anti-Idiotypic
(immunology)
- Antibodies, Monoclonal
- Asthma
(immunology)
- Basophils
(physiology)
- Calcium
(physiology)
- Eosinophils
(physiology)
- Histamine Release
- Humans
- Immunoglobulin E
(physiology)
- Immunoglobulin G
(physiology)
- In Vitro Techniques
- Rhinitis, Allergic, Seasonal
(immunology)
- Temperature
- Tolonium Chloride
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