Eosinophils, allergy and parasites

Recently, known eosinophil functions have been extended considerably: previously the cells were thought to have an exclusive role in the release of cytotoxic mediators; now they are known to have roles in antigen presentation and immunoregulation through the release of cytokines. Although questionable, animal models indicate a rather beneficial role of eosinophils in parasitic infections but a detrimental one, together with other cells, in allergy.