IL-5 is an eosinophil-specific hemopoietic growth factor in human beings. It promotes the
proliferation of bone marrow precursors and their differentiation into eosinophils, and it
promotes eosinophil survival and eosinophil activation? In addition, it primes eosinophils to
respond to chemoattractants such as f-Met-Leu-Phe by cell movement and degranulation. In
mice, IL-5 has an effect on B cells as well. The association of eosinophils with allergic and
parasitic disease has suggested a role for IL-5 in these conditions. The pathogenic nature of …