Antimicrobial Peptides

Antimicrobial Peptides Chairman: Hans G. Boman 1994 Antimicrobial peptides are small peptides directly encoded by genes (in contrast to the better known antibiotics) which show a broad range of activity against Gram-negative and Gram-positive bacteria, fungi, mycobacteria and some enveloped viruses. They were originally identified in insects, but are also produced by mammals, amphibians, crustaceans, bacteria and plants. This book describes studies on a range of such peptides and discusses the application of this research: particularly exciting is the potential use of antimicrobial peptides in the treatment of infectious diseases caused by pathogens that have become resistant to conventional antibiotics, an increasing public health problem. Antimicrobial proteins from plants fall into six structural classes; combinations of peptides from different classes can show synergistically enhanced antifungal activity. Studies are described in which tobacco plants transformed with cDNAs for these peptides show enhanced resistance to pathogenic fungi and it is likely that this will prove to be a way to protect crop plants. Antimicrobial peptides form an important component of the immune response in insects. Genes encoding the cecropins are strongly induced by various microbial substances; the signal transduction pathway leading to this gene activation is being studied in Drosophila. Better understanding of the relationship between inducible peptides and bacterial and parasitic infections in insects that act as vectors for the pathogens of human diseases, such as the mosquitoes that transmit malaria and yellow fever, might provide strategies for the control of such diseases. This book also describes the large number of antimicrobial peptides produced by frogs. Among these, the best known are the magainins, broad-spectrum membrane-active antimicrobial peptides found in the skin of Xenopus laevis, which are being developed as human therapeutic agents. The role of antimicrobial peptides in relation to the mammalian immune system is also discussed. They are made in circulating phagocytic cells and at mucosal surfaces-important sites of interaction with pathogens. Other recent Ciba Foundation Symposia: No. 171 Secondary metabolites: their function and evolution Chairman: Julian Davies 1992 ISBN 0 471 93447 X No. 185 Ethnobotany and the search for new drugs Chairman: Ghillean Prance 1994 ISBN 0 471 95024 6 No. 187 Vaccines against virally induced cancers Chairman: Ian Frazer 1994 ISBN 0 471 95026 2