Serum amyloid A (SAA) is a 12-kDa protein secreted in large amounts by liver cells during microbial infections or inflammatory diseases, We have recently reported that SAA induces chemotaxis of polymorphonuclear cells (PMN), monocytes, and T lymphocytes and stimulates their adhesion to endothelial monolayers. In this study, we investigated whether SAA regulates PMN antimicrobial activities. We found that recombinant SAA (rSAA), at concentrations comparable to serum levels attained during an acute phase response, is a potent activator of PMN. Stimulation of PMN by rSAA results in a rapid and transient increase of cytosolic calcium concentration and up-regulation of cell-surface expression of antigens involved in adhesion and microbial recognition such as CD11c and CD16. In addition, stimulation of PMN with rSAA increases secretion of lactoferrin, an antimicrobial protein that is contained in specific granules of PMN and enhances PMN phagocytic activity against heat-killed Candida albicans. Finally, activation of PMN with rSAA enhances their anti-Candida activity within 30 min of stimulation. These results suggest that SAA is involved in up-regulating PMN antimicrobial activities and that high circulating concentrations of SAA as seen in the acute phase response may constitute a potential host defense mechanism against fungal infections.

Serum amyloid A is an activator of PMN antimicrobial functions: induction of degranulation, phagocytosis, and enhancement of anti-Candida activity / R., Badolato; J. M., Wang; A., Negro Ponzi; Duse, Marzia; T., Musso. - In: JOURNAL OF LEUKOCYTE BIOLOGY. - ISSN 0741-5400. - STAMPA. - 67:3(2000), pp. 381-386.

Serum amyloid A is an activator of PMN antimicrobial functions: induction of degranulation, phagocytosis, and enhancement of anti-Candida activity

DUSE, MARZIA;
2000

Abstract

Serum amyloid A (SAA) is a 12-kDa protein secreted in large amounts by liver cells during microbial infections or inflammatory diseases, We have recently reported that SAA induces chemotaxis of polymorphonuclear cells (PMN), monocytes, and T lymphocytes and stimulates their adhesion to endothelial monolayers. In this study, we investigated whether SAA regulates PMN antimicrobial activities. We found that recombinant SAA (rSAA), at concentrations comparable to serum levels attained during an acute phase response, is a potent activator of PMN. Stimulation of PMN by rSAA results in a rapid and transient increase of cytosolic calcium concentration and up-regulation of cell-surface expression of antigens involved in adhesion and microbial recognition such as CD11c and CD16. In addition, stimulation of PMN with rSAA increases secretion of lactoferrin, an antimicrobial protein that is contained in specific granules of PMN and enhances PMN phagocytic activity against heat-killed Candida albicans. Finally, activation of PMN with rSAA enhances their anti-Candida activity within 30 min of stimulation. These results suggest that SAA is involved in up-regulating PMN antimicrobial activities and that high circulating concentrations of SAA as seen in the acute phase response may constitute a potential host defense mechanism against fungal infections.
2000
acute phase reactants; flow cytometry; respiratory burst; yeast
01 Pubblicazione su rivista::01a Articolo in rivista
Serum amyloid A is an activator of PMN antimicrobial functions: induction of degranulation, phagocytosis, and enhancement of anti-Candida activity / R., Badolato; J. M., Wang; A., Negro Ponzi; Duse, Marzia; T., Musso. - In: JOURNAL OF LEUKOCYTE BIOLOGY. - ISSN 0741-5400. - STAMPA. - 67:3(2000), pp. 381-386.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/95365
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