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Platelets expressing IgG receptor FcγRIIA/CD32A determine the severity of experimental anaphylaxis.
- Source :
-
Science immunology [Sci Immunol] 2018 Apr 13; Vol. 3 (22). - Publication Year :
- 2018
-
Abstract
- Platelets are key regulators of vascular integrity; however, their role in anaphylaxis, a life-threatening systemic allergic reaction characterized by the loss of vascular integrity and vascular leakage, remains unknown. Anaphylaxis is a consequence of inappropriate cellular responses triggered by antibodies to generally harmless antigens, resulting in a massive mediator release and rapidly occurring organ dysfunction. Human platelets express receptors for immunoglobulin G (IgG) antibodies and can release potent mediators, yet their contribution to anaphylaxis has not been previously addressed in mouse models, probably because mice do not express IgG receptors on platelets. We investigated the contribution of platelets to IgG-dependent anaphylaxis in human IgG receptor-expressing mouse models and a cohort of patients suffering from drug-induced anaphylaxis. Platelet counts dropped immediately and markedly upon anaphylaxis induction only when they expressed the human IgG receptor FcγRIIA/CD32A. Platelet depletion attenuated anaphylaxis, whereas thrombocythemia substantially worsened its severity. FcγRIIA-expressing platelets were directly activated by IgG immune complexes in vivo and were sufficient to restore susceptibility to anaphylaxis in resistant mice. Serotonin released by activated platelets contributed to anaphylaxis severity. Data from a cohort of patients suffering from drug-induced anaphylaxis indicated that platelet activation was associated with anaphylaxis severity and was accompanied by a reduction in circulating platelet numbers. Our findings identify platelets as critical players in IgG-dependent anaphylaxis and provide a rationale for the design of platelet-targeting strategies to attenuate the severity of anaphylactic reactions.<br /> (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)
- Subjects :
- Anaphylaxis blood
Anaphylaxis pathology
Animals
Blood Platelets metabolism
Humans
Immunoglobulin G immunology
Mice, 129 Strain
Mice, Inbred C57BL
Mice, Knockout
Mice, Transgenic
Platelet Activation
Platelet Count
Receptors, IgG genetics
Receptors, IgG metabolism
Serotonin blood
Serotonin immunology
Severity of Illness Index
Thrombocytosis blood
Thrombocytosis immunology
Anaphylaxis immunology
Blood Platelets immunology
Disease Models, Animal
Receptors, IgG immunology
Subjects
Details
- Language :
- English
- ISSN :
- 2470-9468
- Volume :
- 3
- Issue :
- 22
- Database :
- MEDLINE
- Journal :
- Science immunology
- Publication Type :
- Academic Journal
- Accession number :
- 29654057
- Full Text :
- https://doi.org/10.1126/sciimmunol.aan5997