Eosinophils in allergic diseases: immunopharmacological regulation

Eosinophils (EOS) are cells that have excited great interest among researchers because of their involvement in many phenomena, and particularly those of defence against parasitic infestations and of modulation of allergic inflammatory reactions. The ontogenesis, morphology and functions of EOS are described, and especially the receptors and chemical mediators they synthesize. Particular attention is paid to the EOS role as a central element in allergic inflammation processes, able to maintain the inflammatory state by producing specific cytokines and to cause tissue damage by producing free radicals. The cell's role in the defence against parasitic infestations is also considered. Finally, emphasis is placed on EOS capacity for immunopharmacological regulation by means both of active secretion of regulating substances and of modulation of other substances, able to inhibit certain phases of allergic inflammation.