ENHANCEMENT OF ANTIGEN-SPECIFIC FUNCTIONAL-RESPONSES BY NEUTROPHILS FROM ALLERGIC PATIENTS

It has been demonstrated that neutrophils from healthy donors or from patients with inflammatory disorders can bind immunoglobulin (Ig) E pr oteins through binding to Mac-2/epsilon bp. Functional responses to al lergens were assessed by measuring the respiratory burst and intracell ular Ca2+ levels, and binding of allergens to neutrophils was assessed by flow cytometry analysis and fluorescence microscopy. In this artic le, we demonstrate that neutrophils sensitized to specific allergens ( from allergic patients), but not from healthy donors, are sensitive to allergens of the same type as those that produce clinical allergic sy mptoms. The activation of neutrophils was analyzed by the induction of a respiratory burst that was detected with luminol-dependent chemilum inescence. Intracellular Ca2+ levels increased parallel to those of th e inducing allergens. In addition, the specific binding of allergens o n the cell surface was revealed by now cytometry and allergen-FITC-lab eled staining analyses. The present data suggest a restricted recognit ion of allergen by sensitive neutrophils, probably associated with the specific binding of the allergen to its corresponding IgE molecule, w hich is bound to the Mac-2/epsilon bp structure. These findings demons trate a functional role of allergen-associated neutrophils during the allergic state.