The role of hemocytes, serine protease inhibitors and pathogen-associated patterns in prophenoloxidase activation in the desert locust, Schistocerca gregaria

Vanessa Franssens; Gert Simonet; Bert Breugelmans; Sofie Van Soest; Vincent Van Hoef; Jozef Vanden Broeck

doi:10.1016/j.peptides.2007.07.032

The role of hemocytes, serine protease inhibitors and pathogen-associated patterns in prophenoloxidase activation in the desert locust, Schistocerca gregaria

Peptides. 2008 Feb;29(2):235-41. doi: 10.1016/j.peptides.2007.07.032. Epub 2007 Dec 7.

Authors

Vanessa Franssens¹, Gert Simonet, Bert Breugelmans, Sofie Van Soest, Vincent Van Hoef, Jozef Vanden Broeck

Affiliation

¹ Laboratory of Developmental Physiology, Genomics and Proteomics, Department of Animal Physiology and Neurobiology, Zoological Institute, K.U. Leuven, Naamsestraat 59, B-3000 Leuven, Belgium.

PMID: 18207608
DOI: 10.1016/j.peptides.2007.07.032

Abstract

The prophenoloxidase-activating system is an important component of the innate immune response of insects, involved in wound healing and melanotic encapsulation. In this paper we show that in the desert locust, Schistocerca gregaria, hemocytes, challenged with microbial elicitors, are indispensable for the limited proteolytic activation of prophenoloxidase (proPO) in plasma. In addition, we assessed the influence of serine protease inhibitors on the induction of PO-activity in plasma. While soybean Bowman-Birk inhibitor (SBBI) inhibited the PO activation by laminarin-treated hemocytes, the endogenous pacifastin-related inhibitors, SGPI-1 (S. gregaria pacifastin-related inhibitor-1) and SGPI-2 did not affect the PO-activity under similar conditions. On the other hand, real-time PCR analysis revealed that the transcripts, encoding SGPI-1-3, were more abundant in the fat body of immune challenged animals, as compared to control animals.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Catechol Oxidase / blood
Catechol Oxidase / metabolism*
Chymotrypsin / pharmacology
Dose-Response Relationship, Drug
Enzyme Activation / drug effects
Enzyme Precursors / blood
Enzyme Precursors / metabolism*
Fat Body / drug effects
Fat Body / metabolism
Female
Gene Expression / drug effects
Glucans
Grasshoppers / enzymology*
Grasshoppers / microbiology
Hemocytes / chemistry
Hemocytes / drug effects
Hemocytes / metabolism*
Hemolymph / metabolism
Host-Pathogen Interactions
Humans
Insect Proteins / genetics
Insect Proteins / metabolism
Insect Proteins / pharmacology
Lipopolysaccharides / pharmacology
Models, Biological
Peptides / genetics
Peptides / metabolism
Peptides / pharmacology
Polysaccharides / pharmacology
Serine Proteinase Inhibitors / genetics
Serine Proteinase Inhibitors / metabolism
Serine Proteinase Inhibitors / pharmacology*
Trypsin Inhibitor, Bowman-Birk Soybean / pharmacology
Trypsin Inhibitors / pharmacology

Substances

Enzyme Precursors
Glucans
Insect Proteins
Lipopolysaccharides
Peptides
Polysaccharides
SGPI I protein, Schistocerca gregaria
SGPI II protein, Schistocerca gregaria
Serine Proteinase Inhibitors
Trypsin Inhibitor, Bowman-Birk Soybean
Trypsin Inhibitors
laminaran
pro-phenoloxidase
Catechol Oxidase
Chymotrypsin