Innate Immunity
ISOLATION OF SEVERAL CYSTEINE-RICH ANTIMICROBIAL PEPTIDES FROM THE BLOOD OF A MOLLUSC, MYTILUS EDULIS*
- Maurice Charlet‡§,
- Serguey Chernysh§¶,
- Hervé Philippe∥,
- Charles Hetru‡,
- Jules A. Hoffmann‡ and
- Philippe Bulet‡**
- From the ‡ Unité Propre de Recherche 9022 Réponse Immunitaire et Développement chez les Insectes, CNRS, Institut de Biologie Moléculaire et Cellulaire, 15, rue René Descartes, 67084 Strasbourg Cedex, France, the
- ¶ Laboratory of Entomology, St. Petersburg State University, Orianienbaumskoye ulitsa, 2, 198904 St. Petersburg, Russia, and the
- ∥ Unité de Recherche Associée 1134 Développement et Morphogénèse, CNRS, Université Paris XI, Bat 445, 91405 Orsay Cedex, France
- ** To whom correspondence should be addressed. Tel.: 33-88-41-70-62; Fax: 33-88-60-69-62.
Abstract
We have isolated from the blood of immune-challenged and untreated mussels (Mytilus edulis) antibacterial and antifungal peptides. We have characterized two isoforms of a novel 34-residue, cysteine-rich, peptide with potent bactericidal activity and partially characterized a novel 6.2-kDa antifungal peptide containing 12 cysteines. We report the presence of two members of the insect defensin family of antibacterial peptides and provide a phylogenetic analysis that indicates that mollusc and arthropod defensins have a common ancestry. Our data argue that circulating antimicrobial peptides represent an ancient host defense mechanism that predated the separation between molluscs and arthropods at the root of the Cambrian, about 545 million years ago.
Footnotes
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↵§ The first two authors contributed equally to this paper.
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↵* This study was supported by CNRS, the University Louis Pasteur of Strasbourg, and Rhône-Poulenc Agro. The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵1 The abbreviations used are:
- MIC
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minimal inhibitory concentration
- HPLC
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high performance liquid chromatography
- AB
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antibacterial
- AF
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antifungal.
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- Received March 25, 1996.
- Revision received May 20, 1996.
- © 1996 by The American Society for Biochemistry and Molecular Biology, Inc.
