In a review article published in the January 24 issue of the journal Nature, Michael Zasloff, MD, PhD, Georgetown University Medical Centers Dean of Research and Translational Science, describes how antimicrobial peptides, molecules that exist throughout the plant and animal kingdoms, are inspiring the design of new antibiotics that may help conquer the growing problem of resistance to conventional antibiotics.

Defending the multicellular organism in which they live, antimicrobial peptides target a disease-carrying microbes bacterial membrane, which Dr. Zasloff labels a previously under-appreciated microbial Achilles heel, making it difficult for the microbe to resist their assault. Every plant and animal species harbors a unique, specific collection of antimicrobial peptides, Dr. Zasloff reports, tuned to defend the organism against microorganisms that it will encounter.

The study of antimicrobial peptides in plants and animals has provided insights into the innate defense systems that permit multicellular organisms, including humans, to live in harmony with microbes, Dr. Zasloff notes. Insects, octopuses and starfish, for example, rely heavily on antimicrobial peptides for defense against deadly microbes, and do so quite effectively without the help of lymphocytes, a thymus or antibodies.

Multicellular organisms live, by and large, harmoniously with microbes. The cornea of the eye of an animal is almost always free of signs of infection. The insect flourishes without lymphocytes or antibodies. A plant seed germinates successfully in the midst of soil microbes, writes Dr. Zasloff. How is this accomplished? Both animals and plants possess potent, broad-spectrum antimicrobial peptides, which they use to fend off a wide range of microbes, including bacteria, fungi, viruses and protozoa. What sorts of molecules are they? How are they employed by animals in their defense? As our need for new antibiotics becomes more pressing, could we d
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Contact: Amy DeMaria
demariaa@georgetown.edu
202-687-6981
Georgetown University Medical Center
23-Jan-2002