Enhancement of neutrophil‐mediated phagocytosis by human granulocyte‐macrophage colony‐stimulating factor demonstrated using a novel mathematical model

Abstract

Sunimar>'. A mathematical model is presenied which may be applied to describe and analyse daia from microscopic phagocyiosis assays. The meihod has been used to investigate the phagocytosis of opsonized yeast by peripheral blood neutrophils Ireatcd with purified recombinam human granulocyte-macrophage colony-stimulating factor {rH GM-CSF) m vitro. Under limiting conditions of scrum opsonization, rH GM-CSF decreased the proportion of non-phagocyiic cells and increased the mean number of ingested yeast per cell. Slimulation of phagocytosis was dose-dependent and occurred with concentrations of rH GM-CSF in the range 10-320 uniis/ml. The effect was dependent on a heat-labile component in serum and was not attributable to endotoxin contamination of the preparation.

Nanoparticles enhance the ability of human neutrophils to exert phagocytosis by a Syk-dependent mechanism

“…Of note, this concentration was previously used for experiments regarding the effect of different NPs on human neutrophil biology [17, 18,29]. As expected, GM-CSF, used here as a positive control, also induced phagocytosis by a factor of about 2 (from 20% to 40%) [31]. Because a different numbers of SRBCs per neutrophil could be observed during this assay (mostly one, but sometime 2 and rarely 3), we next determined whether a specific NP could also increase the number of ingested SRBCs/cell after 30 min of treatment.…”

“…Neutrophils were treated with the following agents: buffer (negative Ctrl), 65 ng/ml GM-CSF (positive control) [31] or different concentrations of NPs, as specified and for the indicated periods of time, and then incubated in a 1:5 ratio with opsonized SRBCs for 30 min at 37°C. In some experiments, cells were treated with the Syk inhibitor piceatannol (30µM)…”

Damage-Associated Molecular Pattern S100A9 Increases Bactericidal Activity of Human Neutrophils by Enhancing Phagocytosis

“…4B). Interestingly, the effect of S100A9 was stronger than the positive control, GM-CSF (32,43). Although concentrations of 40-100 mg/ml S100A9 were found to be optimal, concentrations as low as 1 mg/ml showed a significant effect on phagocytosis (Fig.…”

“…Phagocytosis is expressed as the percentage of neutrophils having ingested at least one opsonized SRBC or neutrophils having ingested two or more opsonized SRBCs (phagocytosis index). GM-CSF (65 ng/ml) was used as a positive control (32 …”

The Florey Lecture, 1991. The colony-stimulating factors: discovery to clinical use

“…Slightly more complex are the demonstrable actions of CSFs in enhancing a range of functional activities of mature granulocytes and macrophages which includes adherence (Arnaout et al 1986;Deveaux et al 1989), chemotaxis (Gasson et al 1984;Wang et al 1987), phagotycosis (Fleischmann et al 1986;Williamson & Brown 1987), increased superoxide production (Vadas et al 1983;Wing et al 1985;Weisbart et al 1987), cytotoxicity for cells or microorganisms (Handman & Burgess 1979;Wing et al 1982;Lopez al. 1983;Ralph et al 1983;Villalta & Kieszenbaum 1986;Grabstein et al 1987;Karabassi et al 1987;Lee & Warren 1987;Ralph & Nakoinz 1987) and the increased synthesis of a variety of products of these cells such as prostaglandin E (Kurland et al 1979), interferon (Warren & Ralph 1986), tumour necrosis factor (Cannistra et al 1987 (Lin & Gordon 1979;Hamilton et al 1980;Lyberg et al 1987) and other growth factors and cytokines (Motoyoshi et al 1982;Horiguchi et al 1987).…”