TNF-induced IL-8 and MCP-1 production in the eosinophilic cell line, EOL-1

Abstract

The role of eosinophils in inflammation and their mode of activation is not well understood. Eosinophil accumulation and subsequent expression of cytokines at the site of inflammation may play a role in exacerbation of inflammatory responses. In the present study, we have examined the role of TNF-a in eosinophil activation and chemokine production using a human leukaemic eosinophil cell line, EOL-1. Initial studies demonstrated that TNF-a induced the upregulation of IL-8 and MCP-1 mRNA and protein. Kinetic studies indicated production of chemokines, IL-8 and MCP-1, as early as 4h post-activation, with peak levels of chemokine produced at 8h, and decreasing by 24 h post-TNF-a activation. When EL-10, a suppressive cytokine, was incubated with TNF-a and EOL-1 cells, no effect was observed on EL-8 and MCP-1 production. However, dexamethasone, a glucocorticoid, demonstrated potent inhibitory effects on the EOL-l-derived chemokines. These studies indicate that eosinophils may be a significant source of chemokines capable of participating in, and maintaining, leukocyte recruitment during inflammatory responses, such as asthma. © 1996, Rapid Science Publishers.