MODULATORY ROLE OF EOSINOPHILS IN ALLERGIC INFLAMMATION - NEW EVIDENCE FOR A RATHER OUTDATED CONCEPT

The eosinophilic response has been identified as a key alteration in t he pathogenesis of asthma and other allergic diseases. A close-correla tion between disease severity and eosinophilia, and the eosinophil abi lity to provide toxic and pro-inflammatory agents ave the major elemen ts supporting the interpretation that there is indeed a causal relatio nship between these phenomena. Nevertheless, controversy still persist s since some studies have clearly demonstrated that eosinophil infiltr ation is not necessarily accompanied by tissue damage or hyperresponsi veness. In addition, there ave some examples in the literature in whic h such alterations are not modified following abrogation of eosinophil influx. In this review it will be argued, based on a model of IgE-dep endent pleurisy, that eosinophil infiltration can be associated with d own-regulation of allergic inflammatory response. The potential mechan ism by which eosinophils could be acting as a immunomodulatory cells i n this particular system will also be assessed.