Comparative analysis of phagocytosis of fungal cells by insect hemocytes versus horse neutrophils.
In this study, the phagocytic ability of Spodoptera exigua hemocytes was compared to horse neutrophils. In vitro assays showed that the insect granulocytes and horse neutrophils actively phagocytose FITC-labeled Paecilomyces farinosus blastospores opsonized with S. exigua hemolymph lectin or horse serum, respectively. Killing of fungal cells by the neutrophils and hemocytes was analyzed under in vitro conditions. Neutrophils reduced the growth of P. farinosus up to 65% whereas no fungicidal activity was observed with hemocyte monolayers. The production of oxygen metabolites by both phagocytic cells incubated with various elicitors (fungal cells, bacteria, phorbol myristate acetate) was examined using luminol-enhanced chemiluminescence. Phagocytosis of opsonized microbes by horse neutrophils resulted in marked increase of chemiluminescence activity whereas no chemiluminescence was detected in similarly challenged phagocytic insect hemocytes. Electron microscopy was used to examine phagocytic events and confirmed that insect phagocytes were unable to kill tested microbes.
Mazet
I
I
Department of Entomology, University of Florida, Gainesville 32611, USA.
Pendland
J
J
Boucias
D
D
D000818:Animals; D006434:Hemocytes / Q000276:immunology* / Q000648:ultrastructure; D006736:Horses / Q000276:immunology; D008163:Luminescent Measurements; D008262:Macrophage Activation; D008856:Microscopy, Fluorescence; D009504:Neutrophils / Q000276:immunology* / Q000648:ultrastructure; D010143:Paecilomyces / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology*; D017382:Reactive Oxygen Species / Q000737:chemistry; D018411:Spodoptera / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D017382:Reactive Oxygen Species; D013755:Tetradecanoylphorbol Acetate