Identification of the cytokine RANTES released from platelets as an eosinophil chemotactic factor.

Selective infiltration of eosinophils suggests the presence of the factors that attract eosinophils preferentially. Selective chemotactic polypeptides for human eosinophils were purified from thrombin-stimulated platelet supernatants and this chemotaxin was identified as the chemokine RANTES. The isolation of natural RANTES and its activity for eosinophil migration is summarized here. RANTES induced eosinophil migration at nanomolar range, in both chemotactic and chemokinetic manners. Specific desensitization experiments indicated that RANTES binds to receptors different from those for C5a and PAF, well-known potent eosinophil chemotaxins.