Related Experiment Video
Updated: Jun 10, 2026
Basophil Activation Test for Allergy Diagnosis
Published on: May 31, 2021
Expression of CD203c and CD63 in human basophils: relationship to differential regulation of piecemeal and
1Johns Hopkins Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA. dmacglas@jhmi.edu
Background:
Activation of human basophils results in the release of many different mediators and the expression of new cell surface proteins. The markers CD63 and CD203c have been used in recent years to assess basophil activation but there have been many studies that demonstrate that expression of these markers can be dissociated from histamine release.
Objective:
To determine the signal transduction requirements for CD203c and CD63 expression.
Methods:
The current study began by exploring the dependency of CD203c and CD63 expression on protein kinase C (PKC) using known selective inhibitors of PKC.
Results:
Between 30 and 300 nm, Ro-31-8220 and bisindoylmaleimide II (Bis II) had no effect on formyl-met-leu-phe- or anti-IgE-induced CD63 or CD203c but enhanced IgE-mediated expression of CD63 by an average of 15-fold at concentrations >1 microm. These results led to the suggestion that these inhibitors altered the normal pathways of degranulation (by a non-PKC dependent mechanism), shifting the normal presence of piecemeal degranulation to the process termed anaphylactic degranulation (AND). Morphological studies demonstrated that concentrations of Ro-31-8220 and Bis II>1 mum dramatically increased the presence of degranulation sacs, a morphological feature of AND.
Conclusion:
It is proposed that CD63 expression results from only the AND form of histamine release.
