Induction of hypodense eosinophils and nuclear hypersegmentation of eosinophils by various chemotactic factors and lymphokines in vitro.

We have previously reported pulmonary eosinophils in eosinophilic pneumonia (PIE syndrome) showed two characteristics: hypodensity and nuclear hypersegmentation. Our present working hypothesis is that the eosinophil chemotactic factor and certain lymphokines may be involved in the induction of these characteristic features. Therefore, we examined whether these stimuli can induce two characteristics in vitro. Results were as follows. 1) Chemoattracts (ECF-A, histamine and PAF) can induce both nuclear hypersegmentation and hypodense eosinophils. 2) Hypodense eosinophils can be induced earlier than induction of hypersegmented nuclei (hypodense eosinophils within three hours, hypersegmented nuclei: 12 hrs). 3) Furthermore, lymphokines can not induce hypodense eosinophil. 4) However, PHA-lymphocyte culture medium (PHALCM), gamma-IFN and IL-3 + GM-CSF can induce hypersegmented nuclei but IL-2 has no effect on nuclear segmentation of eosinophils.