Fungal peptide Destruxin A plays a specific role in suppressing the innate immune response in Drosophila melanogaster.

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TitleFungal peptide Destruxin A plays a specific role in suppressing the innate immune response in Drosophila melanogaster.
Publication TypeJournal Article
Year of Publication2007
AuthorsPal, S, St Leger, RJ, Wu, LP
JournalJ Biol Chem
Volume282
Issue12
Pagination8969-77
Date Published2007 Mar 23
ISSN0021-9258
KeywordsAnimals, Anti-Infective Agents, Depsipeptides, Drosophila melanogaster, Escherichia coli, Evolution, Molecular, Fungal Proteins, Gene Expression Regulation, Immune System, Oligonucleotide Array Sequence Analysis, Peptides, Phagocytosis, Sepsis, Signal Transduction
Abstract

Destruxins are a class of insecticidal, anti-viral, and phytotoxic cyclic depsipeptides that are also studied for their toxicity to cancer cells. They are produced by various fungi, and a direct relationship has been established between Destruxin production and the virulence of the entomopathogen Metarhizium anisopliae. Aside from opening calcium channels, their in vivo mode of action during pathogenesis remains largely uncharacterized. To better understand the effects of a Destruxin, we looked at changes in gene expression following injection of Destruxin A into the fruit fly Drosophila melanogaster. Microarray results revealed reduced expression of various antimicrobial peptides that play a major role in the humoral immune response of the fly. Flies co-injected with a non-lethal dose of Destruxin A and the normally innocuous Gram-negative bacteria Escherichia coli, showed increased mortality and an accompanying increase in bacterial titers. Mortality due to sepsis was rescued through ectopic activation of components in the IMD pathway, one of two signal transduction pathways that are responsible for antimicrobial peptide induction. These results demonstrate a novel role for Destruxin A in specific suppression of the humoral immune response in insects.

DOI10.1074/jbc.M605927200
Alternate JournalJ. Biol. Chem.
PubMed ID17227774
Grant ListR01 GM62316 / GM / NIGMS NIH HHS / United States