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Degranulation from human eosinophils stimulated with C3a and C5a
S Takafuji1, K Tadokoro, K Ito
1Department of Medicine and Physical Therapy, Faculty of Medicine, University of Tokyo, Japan.
International Archives of Allergy and Immunology
|January 1, 1994
Summary
Complement factors C3a and C5a trigger eosinophil cationic protein (ECP) release from human eosinophils. This suggests their role in hypersensitivity diseases by promoting eosinophil degranulation.
Area of Science:
- Immunology
- Cell Biology
Background:
- Eosinophil degranulation is crucial in hypersensitivity diseases.
- The in vivo triggers for eosinophil degranulation remain unclear.
Purpose of the Study:
- To investigate the role of complement factors C3a and C5a in inducing eosinophil degranulation.
- To examine eosinophil cationic protein (ECP) release in response to C3a and C5a.
Main Methods:
- Human eosinophils (Eos) were preincubated with cytochalasin B.
- ECP release was measured in response to varying concentrations of C3a and C5a.
- Intracellular calcium ion concentration ([Ca2+]i) changes were monitored.
Main Results:
- C3a and C5a induced significant ECP release from eosinophils, especially when preincubated with cytochalasin B.
- ECP release induced by C3a and C5a was more potent than that induced by platelet-activating factor (PAF).
- C3a and C5a rapidly and transiently increased intracellular calcium levels in eosinophils.
Conclusions:
- C3a and C5a are potent inducers of eosinophil degranulation.
- These complement factors may play a significant role in the pathogenesis of hypersensitivity diseases.