Human polymorphonuclear leukocytes (PMN) are a first line of defense against fungal infections. PMN express numerous pattern recognition receptors (PRR) that facilitate identification of invading microorganisms and ultimately promote resolution of disease. Dectin-1 (β-glucan receptor) is a PRR expressed on several cell types and has been studied on monocytes and macrophages. However, the role played by dectin-1 in the recognition and killing of fungi by PMN is unknown. We investigated the ability of dectin-1 to mediate human PMN phagocytosis and fungicidal activity. Dectin-1 was expressed on the surface of PMN from all subjects tested (n=29) and in an intracellular compartment that co-sedimented with azurophilic granules in Percoll density gradients. Soluble β-glucan and mAb GE2 (anti-dectin-1) inhibited binding and phagocytosis of zymosan by human PMN (e.g., ingestionwas inhibited 40.1% by 3O min, p<0.001), and blocked reactive oxygen species production. Notably, soluble β-glucan and GE2 inhibited phagocytosis and killing of Candida albicans by PMN (inhibition of killing was 54.8% for β-glucan and 36.2% for GE2, p<0.01). Our results reveal a mechanism whereby PMN dectin-1 plays a key role in the recognition and killing of fungal pathogens by the innate immune system.
Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-19138 |
Date | 01 February 2007 |
Creators | Kennedy, Adam D., Willment, Janet A., Dorward, David W., Williams, David L., Brown, Gordon D., DeLeo, Frank R. |
Publisher | Digital Commons @ East Tennessee State University |
Source Sets | East Tennessee State University |
Detected Language | English |
Type | text |
Source | ETSU Faculty Works |
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