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 the phosphorylation status of cells. CD148 is a recently described membrane-type PTP. In this study, we have demonstrated that this molecule is expressed on human eosinophils and eosinophilic cell line EoL-3. Interestingly, our data also showed that this molecule acts as a transduction molecule on these cells. Thus, the crosslinking of CD148 was able to induce the degranulation and the induction of superoxide anion generation. By using specific inhibitor and by western blotting, we have shown that tyrosine kinase activation is involved in this transduction pathway. In addition, we have shown the presence of a serine/threonine kinase activity associated with CD148. In conclusion, the activation capacity of CD148 on eosinophils suggests a potential role of this molecule on inflammatory diseases, such as allergic and parasitic diseases, associated with eosinophilia.