The role of caspase activation and mitochondrial depolarisation in cultured human apoptotic eosinophils

Abstract EN

-Caspases are key intracellular molecules in the control of apoptosis, but little is known concerning their relative contribution to the cascade of events leading to eosinophil apoptosis.

We examined caspase-3, -8, and -9 activities in receptor ligation dependent apoptosis induction in the cultured eosinophils (CE).

CE cultured alone for 48 hours exhibited constitutive apoptosis (12% ± 1.2).

Significant (P < 0.05) enhancement of eosinophil apoptosis was observed following monoclonal antibody (Mab) treatment with CD45 (40% ± 0.7), CD95 (36% ± 1.6), or CD69 (34% ± 0.2).

Caspase activity was analysed using the novel CaspaTagTM technique and flow cytometry.

CE ligated with CD45 (Bra55), CD95 (Fas) and CD69 Mab resulted in caspase-3 and -9 activation after 16 hours post-ligation.

This trend in caspase-3 and -9 activation continued to increase significantly through to the 20 and 24 hours time points when compared to isotype control.

Activated up-stream caspase-8 was detected 16 and 20 hours after treatment with CD45, CD95 and * Corresponding author.

E-mail address: fqalenzi@ksu.edu.sa (F.Q.

Alenzi).