Fig 1: Establishment of in vitro eosinophil activation model and increased CCL2 release in activated eosinophils. A, The schema of butyric acid induced eosinophil differentiation, and activation by elastin and cathepsin G. B, Liu's staining of the HL-60 clone 15 (HC15) with or without butyric acid treatment. Scale bar: 10um. C, Representative image of immunofluorescent staining of HC15 differentiation into eosinophil and activation. Green: Siglec-8. Blue: DAPI. Scale bar: 10um. D, Cytokine array screening of culture medium from untreated HC15 and from activated eosinophils. The list of cytokine/ chemokine were documented in supplementary table 2. E, Image J quantification of cytokine array signal intensity. F, TCA precipitation of culture medium from HC15 and eosinophils (Eos) and western blot analysis of CCL-2 protein.