Immune suppression of Galleria mellonella (Insecta, Lepidoptera) humoral defenses induced by Steinernema feltiae (Nematoda, Rhabditida): involvement of the parasite cuticle

• Published in: Experimental parasitology Vol. 101; no. 2; pp. 149 - 156
• Main Authors: Brivio, Maurizio F, Pagani, Manuela, Restelli, Stefano
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.06.2002; Elsevier
• Subjects: Animals; Biological and medical sciences; Biological control; Control; Endopeptidases - metabolism; Fundamental and applied biological sciences. Psychology; Hemolymph - enzymology; Hemolymph - parasitology; Host-Parasite Interactions; Insecta; Invertebrates; Larva - immunology; Moths - immunology; Pathology; Pest Control, Biological; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrates; Rhabditida - physiology; Rhabditida - ultrastructure; Host parasite relation; Entomopathogen; Insecta; Biological control; Cuticle; Steinernema feltiae; Pyralidae; Pest; Enzymatic activity; Nematoda; Humoral immunity; Immune response; Hemolymph; Parasite; Parasitosis; Galleria mellonella; Helminthiasis; Infection; Pathogenicity; Immunosuppression; Larva; Arthropoda; Lepidoptera; Nematode disease; Helmintha; Defense mechanism; Nemathelminthia; Invertebrata
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/S0014-4894(02)00111-X

Immune depression of Galleria mellonella larvae was evaluated a short time after infection with the entomopathogenic nematode Steinernema feltiae. In the host the activity of the enzymatic cascade known as the proPO system was significantly reduced by the presence of either live or dead parasites. The presence of parasites decreased the LPS-elicited proPO system activity. In addition, this process seems to be related to a decrease in the activity of hemolymph proteases, more than to phenoloxidase damage. proPO inhibition was also achieved by injected isolated cuticle fragments, suggesting that the parasite body surface plays an important role in the early parasitation phase. Index Descriptors and Abbreviations: proPO system; Steinernema feltiae, Galleria mellonella, insects, nematodes, cuticle, host–parasite interactions. PMSF: phenylmethylsulphonylfluoride; EDTA: ethylendiamine tetraacetic acid; Tris: Tris(hydroxymethyl)aminomethane; l-Dopa: l-3,4-dihydroxyphenylalanine; TNBSA: 2,4,6-trinitrobenzene sulfonic acid; CFF: cell-free fraction.