Expression on human eosinophils of CD148: a membrane tyrosine phosphatase.Implications in the effector function of eosinophils

The role of protein tyrosine phosphatases (PTP) is crucial in regulating th e phosphorylation status of cells. CD148 is a recently described membrane-t ype PTP, In this study, we hare demonstrated that this molecule is expresse d on human eosinophils and eosinophilic cell Line EoL-3, Interestingly, our data also showed that this molecule acts as a transduction molecule on the se cells. Thus, the crosslinking of CD148,vas able to induce the degranulat ion and the induction of superoxide anion generation. By using specific inh ibitor and by western blotting, we have shown that tyrosine kinase activati on is involved in this transduction pathway. In addition, we have Shown the presence of a serine/threonin kinase activity associated with CD148. In co nclusion, the activation capacity of CD148 on eosinophils suggests a potent ial role of this molecule on inflammatory diseases, such as allergic and pa rasitic diseases, associated,with eosinophilia.