The dual functionality of antimicrobial peptides Os and Os‐C in human leukocytes

Abstract

Antimicrobial peptides (AMPs), Os and Os-C, have been identified as multifunctional peptides with antibacterial, antiendotoxin, and anti-inflammatory properties. For further development of Os and Os-C as therapeutic peptides, it is essential to evaluate these effects in human mononuclear (MN) and polymorphonuclear (PMN) leukocytes. The cytotoxicity and the effects of both peptides on MN and PMN morphology were determined with the Alamar-Blue assay and scanning electron microscopy, respectively. The ability of Os and Os-C to induce reactive oxygen species (ROS) and to protect against 2,2′-azobis(2-amidinopropane) dihydrochloride-induced oxidative damage in both cell populations was evaluated using 2′,7′-dichlorofluorescin diacetate (DCFH-DA). Using fluorescently labeled peptides, the ability of the peptides to cross the cell membranes of MN and PMN was also evaluated. At the minimum bactericidal concentrations of Os and Os-C, neither peptide was cytotoxic. Os caused morphological features of toxicity at 100 μM, entered MN cells, and also protected these cells against oxidative damage. Os-C caused MN and PMN leukocyte activation associated with ROS formation and was unable to penetrate cell membranes, indicating extracellular membrane interactions.This study confirms that both Os and Os-C at less than 100 μM are not cytotoxic. The MN-specific uptake of Os identifies it as a cellspecific cargo-carrier peptide, with additional anti-inflammatory properties. In contrast, the ability of Os-C to activate MN and PMN cells implies that this peptide should be further evaluated as an AMP, which, in addition to its ability to eradicate infection, can further enhance host immunity. These novel characteristics of Os and Os-C indicate that these AMPs as peptides can be further developed for specific applications.

Dual bio-active factors with adhesion function modified electrospun fibrous scaffold for skin wound and infections therapeutics

“…No significant differences in cell proliferation existed between the PLGA and PLGA/NAT-Os scaffolds, for both growth periods of 3 and 7 days, demonstrating the nontoxicity of the NAT-Os. Previous studies have shown that NAT-Os has good cellular compatibility and will not have any negative effect on eukaryotic cells 24 . The results of these studies are similar to the cell proliferation result in this study.…”

“…Antimicrobial peptides (AMPs) are an important part of the innate immune system of organisms and can reasonably solve the problem of bacterial resistance 23 . The short C-terminal peptide Os, from OsDef2, a defensin in the midgut of the soft tick Ornithodoros savignyi , has been studied in the literature 24 . The main antibacterial effects of Os is the destruction of the bacterial cell structure and the indentation of the cell membrane.…”

“…Moreover, Os has been shown to be bactericidal to both Gram-positive and Gram-negative bacteria 25 . It has also been found to have no effect on mammalian cell activity and possess antioxidant activity 24 . Given the above findings, the use of IGF1 and Os combination to improve the antibacterial properties and tissue repair ability of electrospun fibrous scaffold has attracted our attention.…”

Evaluation of Three Antimicrobial Peptides Mixtures to Control the Phytopathogen Responsible for Fire Blight Disease

“…Cell viability is one of the most reliable assessments of the efficacy of AMPs, and has been widely applied in diverse studies [17,26,40,[50][51][52][53]. However, viability can be attributed to different causes, namely, loss of membrane integrity, reduced metabolism, among other factors, which leads to the need of assessing cell viability by resorting to different techniques.…”

Protective effect of Bombyx mori gloverin on intestinal epithelial cells exposure to enterotoxigenic E. coli

“…However, it has no toxic effects on mammalian cells [14]. Although increasing evidences have shown that the AMPs can serve as a critical regulator for diverse biological events including immune responses [16][17][18][19], the mechanism behind the BMGlvA2-regulated immunity is just beginning to be explored.…”