Mast cell and eosinophil surface receptors as targets for anti-allergic therapy

Allergy is the host immune response towards harmless substances, called allergens. Allergic diseases comprise allergic asthma, allergic rhinitis, allergic conjunctivitis, atopic dermatitis, and food allergy. While some drugs counteract the symptoms and the inflammation arising from allergy, no completely effective and acceptable side effect free drug has been developed as yet. Moreover, severe asthma and atopic dermatitis are classified as unmet clinical needs. Mast cells and eosinophils are the main effector cells of the allergic response and thus, must be the first cells targeted to impede the allergic inflammation symptoms and evolution. The presence on mast cells and eosinophils of several surface receptors with either activating or inhibitory functions indicates the possibility of their pharmacological targeting. This review deals with some of the receptors expressed on mast cells and eosinophils and their ligand(s). Some receptors have already been exploited as drug targets and others can be feasibly utilized as novel targets for anti-allergic therapy.