A New Model for Analyzing Antimicrobial Peptides with Biomedical Applications

Book excerpt: Annotation This book is aimed at two audiences. First, it will present evidence for the earthworm's immune system. Second, the results strongly suggest that certain molecules of the earthworm's immune system may be exploited as natural antibiotics--thus the biomedical applications. There are two advantages for using earthworms. First, they are an inexpensive, non-controversial invertebrate model. Second, in contrast to other invertebrates (e.g. Drosophila, C elegans) they are essential for maintaining the integrity of soil. Earthworms have a highly effective immune system since cancer cannot be induced in them nor does it seem to occur in natural populations. Cytotoxicity of cancer cells has been examined in relation to two earthworm leukocytes based upon: structure; cell differentiation antigens; function revealed by FACS and mAbs. These cells are SMALL (8-11 m) electron dense (SC), positive for human cell adhesion molecules (CD11a, CD45RA, CD45RO, CDw49b, CD54, for?2-microglobulin and for Thy-1; LARGE (12-15 m) electron lucent cells (LC), negative for these same markers. Leukocytes synthesize and secrete lytic molecules (fetidins, CCF-1, lysenin, eiseniapore) participate in recognition of, binding to, killing and sequestration of cancer cells in vitro. Earthworm lytic levels are significantly higher than those of human NK cells. Earthworms possess a highly evolved, unique and efficient immune system that has facilitated long-term survival.