MACROPHAGE-MEDIATED CANDIDACIDAL ACTIVITY IS AUGMENTED BY EXPOSURE TOEOSINOPHIL PEROXIDASE - A PARADIGM FOR EOSINOPHIL-MACROPHAGE INTERACTION

Various disease states are associated with eosinophilia and the releas e of eosinophil peroxidase (EPO) into the microenvironment. The presen t study targets the effects of low levels of EPO on macrophage (MO) ph agocytosis and intracellular killing of Candida albicans as well as MO oxidative activity measured as the luminescence product of luminol di oxygenation. Resident murine peritoneal MO were exposed to various con centrations of EPO. Chemiluminescence data indicate that nanomolar con centrations of EPO markedly enhanced the dioxygenation activity (respi ratory burst) of MO. In other studies, the exposure of MO to 0.17 mu M EPO for 10 min. enhanced MO-mediated candidacidal activity 10 fold. T he above data indicate that EPO enhances certain MO functions. Also th e results illustrate a previously un-recognized interaction between eo sinophils and MO and implicate yet another possible role for EPO in ho st defenses against disease.