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Updated: Aug 17, 2026

Humanized Mediator Release Assay as a Read-Out for Allergen Potency
Published on: June 29, 2021
[Histamine release properties of human basophils in response to various stimuli]
Wei Zhu1, Shao-heng He, Zi-xia Lin
1Allergy and Inflammation Research Institute, Medical College, Shantou University, Shantou 515031, China.
Aim:
To investigate the effects of protease activated receptor-2 (PAR-2) agonist, heparin and other stimuli on histamine release from human basophils.
Methods:
Peripheral blood mononuclear cells (PBMCs) were separated by density gradient centrifugation. The PBMCs were then resuspended in complete Hank's balanced salt solution (HBSS) and challenged with various stimulating agents. Histamine level in samples was determined by ELISA.
Results:
10 mg/L trypsin could induce histamine release from basophils. However, its stimulatory effect on basophils was weaker than that of anti-IgE, calcium ionophore (CI), F-Met-Leu-Phe (FMLP), C5a and substance P. PAR-2 agonist SLIGKV-NH(2) failed to activate basophils. Heparin, C5 and adenosine did not induce any histamine release at concentrations tested, but heparin enhanced histamine release induced by C5a and substance P.
Conclusion:
Trypsin, anti-IgE, CI, FMLP, C5a and substance P can induce histamine release from baosophils, but PAR-2 agonist can not. Heparin can greatly enhance the ability of C5a and substance P to stimulate histamine release, which may be a novel mechanism of amplification of basophil activation signal.
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