IPD-1151T (suplatast tosilate), an anti-allergic agent, inhibits platelet-activating factor (PAF)-induced b2 integrin expression on the eosinophilic cell line (EoL-l)☆

Abstract Rationale We have previously examined whether platelet-activating factor (PAF), as a chemotactic agent for eosinophils, is involved in adhesion molecule expression using an eosinophilic cell line(EoL-1), resulting in induction of β 2 integrin family expression by PAF (10 −7 M). IPD-1151T (suplatast tosilate) is a novel anti-allergic agent and has the effect on IgE production on Th2-mediated eosinophilia or on mast cells. Although the effect of IPD - 1151T on eosinophil function is not well demonstrated. Methods In this study, we examined the effect of IPD-1151T on β 2 integrin expression induced by PAF. Results The inhibitory effect of IPD-1151T on β 2 integrin expression induced by PAF, whereas IPD-1151T had no effect on β 2 integrin expression on untreated EoL-l. Moreover, IPD-1151T inhibited adherence of these cells to recombinant soluble ICAM-l-coated plate augmented by PAF, suggesting IPD-1151T down regulates not only surface expression of β 2 integrin family but also functional adherence. Conclusions We would conclude that IPD-1151T (suplatast tosilate) has not only anti-allergic activities but also anti-inflammatory properties for eosinophils.