BACKGROUND The majority of beta-defensin family members are exclusively expressed in the epididymis, and some members have been shown to play essential roles in sperm maturation and fertility in rats, mice and humans. Therefore, beta-defensins are hypothesized to be potential targets for contraception and infertility diagnosis and treatment. Clarifying the regulatory mechanisms for the expressi...

BACKGROUND Defensins, also known as human neutrophil peptides, are antimicrobial peptides present in the azurophil granules of neutrophils. We measured their level in pleural effusion in various pulmonary diseases to investigate whether they could be used as a diagnostic marker in the differential diagnosis of specific pleural diseases. PATIENTS AND PARTICIPANTS We analyzed pleural effusion s...

Theta-defensins are cyclic octadecapeptides encoded by the modified alpha-defensin genes of certain nonhuman primates. The recent demonstration that human alpha-defensins could prevent deleterious effects of anthrax lethal toxin in vitro and in vivo led us to examine the effects of theta-defensins on Bacillus anthracis (Sterne). We tested rhesus theta-defensins 1-3, retrocyclins 1-3, and severa...

Cyclic peptides are receiving significant attention thanks to their antimicrobial activity and high serum stability, which is useful to develop and design novel antimicrobial agents. Antimicrobial peptides appear to be key components of innate defences against bacteria, viruses, and fungi. Among the others, defensins possess a strong microbicidial activity. Defensins are cationic and amphipathi...

Alpha-defensins are antibiotic peptides that act as natural inhibitors of HIV-1 infection. However, the mechanisms of such inhibition are still unclear. Here we demonstrate that alpha-defensins block the earliest steps in the viral infectious cycle, as documented using an HIV-1 envelope-mediated cell-fusion assay. A broad-spectrum inhibitory activity was observed on primary and laboratory-adapt...

beta-Defensins are a family of small cationic peptides involved in the innate response to microbial infection. Although their role in microbial killing is well established, the mechanisms through which this occurs remain largely undefined. Here, using protein array technology, we describe a role for human beta-defensins in the induction of an inflammatory cytokine response by human peripheral b...

ß-defensins are a large family of cationic peptides with antimicrobial activities in vitro against Gram-positive and Gramnegative bacteria, fungi, and enveloped viruses [1]. As such, they are thought to be an important component of the innate immune system and are expressed by cells such as phagocytes and epithelia that are involved in host defence against microbial infections. The defensins fo...

The flowers of the solanaceous plants ornamental tobacco (Nicotiana alata) and petunia (Petunia hybrida) produce high levels of defensins during the early stages of development. In contrast to the well-described seed defensins, these floral defensins are produced as precursors with C-terminal prodomains of 27 to 33 amino acids in addition to a typical secretion signal peptide and central defens...

Over the last years, antimicrobial peptides (AMPs) have been the focus of intense research toward the finding of a viable alternative to current antifungal drugs. Defensins are one of the major families of AMPs and the most represented among all eukaryotic groups, providing an important first line of host defense against pathogenic microorganisms. Several of these cysteine-stabilized peptides p...

Defensins are antimicrobial peptides expressed by plants and animals. In mammals there are three subfamilies of defensins, distinguished by structural features: alpha, beta and theta. Alpha and beta-defensins are linear peptides with broad anti-microbial activity that are expressed by many mammals including humans. In contrast, theta-defensins are cyclic anti-microbial peptides made by several ...