Eosinophil granulocytes: functional differences of a new isolation kit compared to the isolation with anti‐CD16‐conjugated MicroBeads

Abstract

Using a new eosinophil isolation kit, we were not able to confirm our previous findings of a delayed apoptosis of eosinophils in atopic dermatitis. Thus, we investigated whether this new isolation kit modulates the functional activity of eosinophils. Peripheral blood eosinophils were isolated with the new isolation kit as well as conventionally with anti-CD16-conjugated MicroBeads. We analysed viability, apoptosis, CD69 and CD95 expression, streptavidin binding and superoxide anion release. Purity of eosinophils was higher using the new isolation kit (P < 0.05). However, these eosinophils had a decreased survival (P < 0.05-0.01), presented morphological features of apoptosis, showed an increased percentage of apoptotic nuclei (P < 0.01), an increased release of superoxide anions (P < 0.05), a higher expression of CD69 and CD95 (P < 0.05) and an increased binding to streptavidin compared to eosinophils isolated with anti-CD16 conjugated MicroBeads. The new eosinophil isolation kit should not be used for the investigation of eosinophils as it potently affects their functional activity.