ISSN:
1420-908X
Keywords:
Neutrophil
;
Defensin
;
Phagocytosis
;
Adhesion molecule
;
Superoxide anion generation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Defensins are known to be the microbicidal components of neutrophil granules, which contribute to oxygen-independent antimicrobial mechanisms. In this study, we have examined the effect of defensins on neutrophil functions, such as adhesion, superoxide anion generation, phagocytosis and chemotaxis. Guinea-pig defensins increased the expression of CD11b, CD11c and CD54 (intercellular adhesion molecule ICAM-1) on human neutrophils, and induced adhesion of guinea-pig and human neutrophils. When the effect of guinea-pig defensins on superoxide anion generation was examined, defensins inhibited superoxide anion generation during phagocytosis of complement-opsonized particles. Furthermore, defensins inhibited complement-dependent phagocytosis. However, they did not inhibit the binding of complement-opsonized particles to neutrophils, suggesting that defensins possibly inhibit complement-dependent phagocytosis by affecting the ingestion step but not the binding step. Defensins exhibited neither chemotactic nor chemokine activity. Interestingly, 10–20% of total defensins were released extracellularly from phagocytosing neutrophils. Together these observations indicate that, in addition to their antimicrobial activity, defensins may have the ability to modulate the functions of neutrophils at sites of infection or inflammation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02265117
