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Updated: Jul 23, 2026

Development and Identification of a Novel Subpopulation of Human Neutrophil-derived Giant Phagocytes In Vitro
Published on: January 25, 2017
Polymorphonuclear neutrophils release 35S-labelled proteoglycans into cartilage during frustrated phagocytosis
E E Gardiner1, S S Mok, A Sriratana
1Department of Biochemistry, Monash University, Clayton, Australia.
Abstract:
Rabbit peritoneal polymorphonuclear neutrophils (PMN), incubated in medium containing [35S]sulphate, incorporated 35S into proteoglycan and protein fractions. Approximately 46% of the 35S-labelled macromolecules associated with the PMN cells after 1 h of incubation were recovered in a cytoplasmic granule extract, the majority being present in azurophil granules. Analysis of the azurophil granule fraction showed that approximately 90% of the 35S-labelled macromolecules were proteoglycans. When challenged with heat-aggregated rabbit gamma-globulin in the presence of cytochalasin B and cGMP, PMN were induced to release granular enzymes but did not release 35S-labelled proteoglycans into the incubation medium. When incubated with articular cartilage slices, PMN released their granule 35S-labelled proteoglycan into the medium and into the cartilage matrix. Granule enzymes and 35S-labelled granule proteoglycan were extracted from the cartilage tissue after incubation and 35S-labelled macromolecules were detected in the cartilage tissue by autoradiography.
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