The Degranulation Effect of Interleukin 5 on Eosinophils

Abstract

We evaluated the degranulation effect of interleukin (IL) 5 on eosinophils purified from peripheral blood in the subjects with nasal allergy.
Eosinophils were incubated with IL-5, IL-3 and platelet activating factor (PAF) at 37°C for lhr. The release of eosinophil cationic protein (ECP) was measured by radio im munoassay as an index of degranulation. High concentrations of IL-5 and IL-3 induced a significant release of ECPfrom eosinophils, although the amount of ECP was small compared with that in the nasal lavage fluid after antigen challenge. PAF did not have any effect on eoinophil degranulation.
These findings s uggest that the roles of IL-5 and IL-3 on eosinophil degranulation are minimum in vivo.