It is still unknown how eosinophils degranulate in nasal mucus. Currently, cytolysis is being reevaluated as the mode of degranulation of eosinophils in allergic nasal mucosa. To examine whether eosinophils migrating to the nasal mucus degranulate by cytolysis, we sampled nasal mucus from 9 patients with nasal allergy and observed it under electron and light microscopes. Both intact and necrotic eosinophils were observed in the nasal mucus. Although the total eosinophil count in the nasal mucus was not correlated with the frequency of sneezes, there was a significant correlation (p = .0025) between the rate of eosinophil lysis and the frequency of sneezes. Whereas extracellular release of eosinophil peroxidase was not detected from the eosinophils with intact cell membranes, large quantities of eosinophil peroxidase were found outside the eosinophils with injured cell membranes. We concluded that eosinophils migrating to the nasal mucus degranulate mainly by cytolysis, and that granular proteins released from the necrotic eosinophils into the nasal mucus are one of the important factors causing hypersensitivity in the nasal mucosa.
It is known that eosinophil granular proteins cause tissue damage. To explore how eosinophils degranulate, we studied the degranulation of eosinophils that had migrated around fungal hyphae. In electron microscopic observations of allergic mucin from patients with allergic fungal sinusitis, fungal hyphae were detected, surrounded by numerous eosinophils. A number of eosinophils, including many disintegrated eosinophils, adhered to the cuticular layer of the hyphal surface. Although the fungal hyphae were detected in allergic mucins in all 5 patients, fungal hyphae surrounded by eosinophils were observed in only 1 patient. In the eosinophil cytoplasm, the cell membrane was invaginated, deep, and sheetlike, and the space formed by its infolding was filled with a highly electron-dense substance. This substance appeared to be a mixture of the cuticular substance of the hyphal surface and granular proteins. Thus, the eosinophil phagocytosed the cuticular substance of the hyphae into a sheetlike invaginated space, and released granular proteins into that space. The structure invaginated in the cytoplasm retained its form even after disintegration of the eosinophil, and adhered to the cuticular layer. This structure detected in eosinophils has not been reported previously, and is considered to be an interesting finding from the viewpoint of the function of eosinophils.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.