Secretory leukocyte proteinase inhibitor (SLPI) is a serine proteinase inhibitor that is produced locally in the lung by cells of the submucosal bronchial glands and by nonciliated epithelial cells. Its main function appears to be the inhibition of neutrophil elastase (NE). Recently, NE was found to enhance SLPI mRNA levels while decreasing SLPI protein release in airway epithelial cells. Furth...

θ-Defensins are cyclic antimicrobial peptides expressed in leukocytes of Old world monkeys. To get insight into their antibacterial mode of action, we studied the activity of RTDs (rhesus macaque θ-defensins) against staphylococci. We found that in contrast to other defensins, RTDs do not interfere with peptidoglycan biosynthesis, but rather induce bacterial lysis in staphylococci by interactio...

Defensins are small cysteine-rich peptides with antimicrobial activity. Plant defensins have a characteristic threedimensional folding pattern that is stabilized by eight disulfide-linked cysteines. This pattern is very similar to defense peptides of mammals and insects, suggesting an ancient and conserved origin. Functionally, these proteins exhibit a diverse array of biological activities, al...

Defensins comprise one of the largest groups of host defence peptides, present throughout evolution, in fungi and flowering plants as well as in invertebrates and vertebrates. These cysteine-rich, cationic peptides have a common ability to kill a broad range of microorganisms including bacteria, yeast and viruses. As such, they are a strong component of the arsenal that is an organism's innate ...

Fungal resistance to traditional drugs calls for new antimicrobial agents. In mammals, defensins and cathelicidins are two major families of antimicrobial peptides. Cathelicidins are cationic peptides with a conserved N-terminal cathelin-like domain and a variable C-terminal antimicrobial domain. Cathelicidins rapidly kill Candida and other yeast spp.1 Candida infection with C albicans is the f...

Defensins and cathelicidins are the two major families of mammalian anti-microbial proteins. They contribute to host, innate, anti-microbial defense by disrupting the integrity of the bacterial cell membrane. However, several members of the mammalian anti-microbial proteins including defensins and cathelicidins have been shown recently to have chemotactic effects on host cells. Human neutrophil...

Defensins are cationic, cysteine-rich peptides (Mr = 3500-4000) found in the cytoplasmic granules of neutrophils and macrophages. These peptides possess broad antimicrobial activity in vitro against bacteria, fungi, tumor cells, and enveloped viruses, and they are believed to contribute to the "oxygen-independent" antimicrobial defenses of neutrophils and macrophages. Pathophysiologic studies i...

Staphylococcus aureus achieves resistance to defensins and similar cationic antimicrobial peptides (CAMPs) by modifying anionic membrane lipids via MprF with L-lysine, which leads to repulsion of these host defense molecules. S. aureus DeltamprF, which lacks the modification, was very efficiently killed by neutrophil defensins and CAMP-producing leukocytes, even when oxygen-dependent killing wa...