[Eosinophils: structure and functions].

Long considered to be secondary cells characterized mainly by their ability to be recruited to inflammation sites, these cells are now known to release a wide array of cytotoxic mediators. Moreover they participate in immune response regulation by producing Th1 and Th2 cytokines as well as regulatory cytokines and chemokines. This review describes recent findings about their expression of surface molecules, eosinophil mediators, and the role of both in these novel eosinophil functions.