Plant defensins are small, cysteine-rich peptides that possess biological activity towards a broad range of organisms. Their activity is primarily directed against fungi, but bactericidal and insecticidal actions have also been reported. The mode of action of various antifungal plant defensins has been studied extensively during the last decades and several of their fungal targets have been ide...

Defensins released by neutrophils are able to kill a broad spectrum of microbes. They also induce leukocyte migration in vitro and elicit inflammatory leukocyte responses at s.c. injection sites in mice. In vitro experiments showed that human defensins enhanced concanavalin A-stimulated murine spleen cell proliferation and IFN-gamma production. This led us to examine the effects of human defens...

Defensins, a family of cationic, structurally related, antimicrobial peptides, contribute to host defense by disrupting the cytoplasmic membrane of microbes. Here we show that human neutrophil defensins selectively induce the migration of human CD4+/CD45RA+ naive and CD8+, but not CD4+/CD45RO+ memory, T cells. Moreover, human neutrophil defensins are chemotactic for immature human dendritic cel...

Defensins are small cationic peptides with antimicrobial properties. They constitute a highly conserved innate immune defense mechanism across species. Based on the arrangement of disulfide-bonds, αand β-defensins are distinguished in humans. Both types of defensin comprise several distinct molecules that are preferentially expressed at epithelial surfaces and in blood cells. In the last decade...

Defensins are endogenous antimicrobial peptides (AMPs) produced by professional phagocytes, Paneth cells, and epithelial cells at mucosal surfaces, which mediate innate immunity through their potent antimicrobial activity in the intestinal tract. In addition, defensins also regulate the function of diverse host immune cells, thereby play an important role in both innate and adaptive immune resp...

Human α and β-defensins are cationic antimicrobial peptides characterized by three disulfide bonds with a triple stranded β-sheet motif. It is presumed that interaction with the bacterial cell surface and membrane permeabilization by defensins is an important step in the killing process. In this study, we have compared interactions of three human α-defensins HNP3, HNP4, HD5 and human β-defensin...

Ancestral sequence reconstruction has been widely used to test evolution-based hypotheses. The genome of the European tick vector, Ixodes ricinus, encodes for defensin peptides with diverse antimicrobial activities against distantly related pathogens. These pathogens include fungi, Gram-negative, and Gram-positive bacteria, i.e., a wide antimicrobial spectrum. Ticks do not transmit these pathog...

Defensins are a large family of positively-charged antimicrobial peptides that have been implicated innate immunity. Although known for their ability to directly kill bacteria, the mechanisms by which defensins regulate host-pathogen interactions remain elusive. Herein, we deleted entire Defensin gene cluster (3 million base pairs) in keratinocyte-intrinsic manner and observed enhanced suscepti...

Human aand b-defensins are cationic, amphipathic effector peptides of the innate immune system with broad antimicrobial activity [1]. a-defensins are produced by neutrophils (human neutrophil peptides [HNP] 1–4), as well as by epithelial cells in the gut and genitourinary tract (human defensins [HD] 5 and 6). bdefensins (human b-defensins [HBD] 1–4) are constitutively expressed by epithelial ce...

Alpha-defensins are peptides secreted by polymorphonuclear cells and provide antimicrobial protection mediated by disruption of the integrity of bacterial cell walls. Staphylokinase is an exoprotein produced by Staphylococcus aureus, which activates host plasminogen. In this study, we analyzed the impact of interaction between alpha-defensins and staphylokinase on staphylococcal growth. We obse...