Interferon-γ Inhibits in vitro Mobilization of Eosinophils by Interleukin-5

다국어 초록 (Multilingual Abstract)

<P><I>Background:</I> Th2 cytokines play pivotal roles in allergic inflammation, including eosinophilia, and their actions are antagonized by Th1 cytokines, conferring them therapeutic potential. <I>Methods:</I> In this study, we examined the ability of a number of cytokines to suppress the activation of eosinophils that function as effector cells for allergic airway diseases. <I>Results:</I> Interleukin (IL)-5, IL-6, and tumor necrosis factor (TNF) induced an eosinophil shape change, whereas interferon (IFN)-γ significantly inhibited the shape change. Other cytokines, including IL-1β, IL-4, IL-10 and IL-13, had little or only slightly enhancing or reducing effects on the shape change. We further analyzed the IFN-γ effect, showing that pretreatment with IFN-γ strongly suppressed IL-5-induced eosinophil shape change, and cycloheximide (CHX) abrogated the suppression by IFN-γ, suggesting that new protein synthesis is required for the inhibitory effect by this cytokine. In agreement with these results, IFN-γ blocked the eosinophil migration and ERK phophorylation induced by IL-5, and the addition of CHX restored eosinophil chemotaxis. <I>Conclusions:</I> Collectively, IFN-γ may attenuate eosinophilic inflammation by directly negating eosinophil mobilization.</P><P>Copyright © 2005 S. Karger AG, Basel</P>