Phage displayed short peptides against cells of Candida albicans demonstrate presence of species, morphology and region specific carbohydrate epitopes

Polypeptides Targeting Paracoccidioides brasiliensis Drk1

Considering the toxicity of conventional therapeutic approaches and the importance of precise mechanistic targets, it is important to explore signaling pathways implicated in fungal pathobiology. Moreover, treatment of paracoccidioidomycosis, a systemic mycosis caused by a dimorphic fungus, requires prolonged therapeutic regimens. Among the numerous factors underpinning the establishment of Paracoccidioides spp. infection, the capacity to transition from the mycelial to the yeast form is of pivotal importance. The Drk1 protein of Paracoccidioides brasiliensis likely plays a decisive role in this morphological shift and subsequent virulence. We identified peptides with affinity for the PbDrk1 protein using the phage-display method and assessed the effects of these peptides on P. brasiliensis. The peptides were found to inhibit the phase transition of P. brasiliensis. Furthermore, a substantial proportion of these peptides prevented adhesion to pneumocytes. Although these peptides may not possess inherent antifungal properties, they can augment the effects of certain antifungal agents. Notably, the cell wall architecture of P. brasiliensis appears to be modulated by peptide intervention, resulting in a reduced abundance of glycosylated proteins and lipids. These peptides were also evaluated for their efficacy in a Galleria mellonella model and shown to contribute to enhanced larval survival rates. The role of PbDrk1, which is notably absent in mammals, should be further investigated to improve the understanding of its functional role in P. brasiliensis, which may be helpful for designing novel therapeutic modalities.

Strategies and opportunities for engineering antifungal peptides for therapeutic applications

Antifungal peptides (AFPs) are widely described as promising prospects to treat and prevent fungal infections, though they are far less studied than their antibacterial counterparts. Although promising, AFPs have practical limitations that have hindered their use as therapeutics. Rational design and combinatorial engineering are powerful protein engineering strategies with much potential to address the limitations of AFPs by designing peptides with improved physiochemical and biological characteristics. We examine how rational design and combinatorial engineering approaches have already been used to improve the properties of AFPs and propose key opportunities for applying these strategies to push the design and application of AFPs forward.

Phage nanoparticle as a carrier for controlling fungal infection

A mass of nanocarriers have been exploited and utilized for prevention of fungi, including organic nanomaterials, inorganic nanoparticles, polypeptides, and viruses. Due to biological safety and flexible genetic engineering property, bacteriophages, as bionanoparticles, are widely used in the diagnosis and treatment of microorganisms, which can be easily loaded with proteins and drugs. In particular, random DNAs can be inserted into the genome of phage by phage display technology, and it is possible to obtain the peptide/antibody targeting fungi from phage library. Meanwhile, phages displaying specific peptides are able to conjugate with other nanoparticles, which have both characteristics of peptides and nanomaterials, and have been used for precise detection of fungi. Additionally, phage nanomaterials as carriers can reduce the toxicity of drugs, increase the time of drug circulation, stimulate the immune response, and have an anti-fungal effect by itself. In this review, we summarize the recent applications of bacteriophages on the study of fungi. The improvement of our understanding of bacteriophage will supply new tools for controlling fungal infections. These phage libraries were used to pan the specific peptides for diagnosis, prevention, and treatment of fungi. KEY POINTS: • System fungal infection has no significant clinical symptoms; it is important to develop vaccine, diagnosis, and therapeutic agents to reduce mortality; phage is an ideal carrier for vaccine and drug to stimulate immune response and improve the efficiency of drug, and also can improve the sensitivity of detection • This review summarized recent studies on phage-based fungal vaccine and threw light on the developing therapeutic phage in the treatment of fungal infection.

Fabricating Ultra-Smooth Diamond-Like Carbon Film and Investigating its Antifungal and Antibiofilm Activity

Diamond like carbon (DLC) a carbon-based nanomaterial has been nominated as a potential solution to prevent the biofilm formation on indwelling medical devices such as dentures and heart valves.Candidaalbicansis an opportunistic fungal pathogen where biofilms are a part of its pathogenicity which primarily utilized indwelling medical devices as platform to build up the biofilm. In this work, DLC deposited on silicon substrate was prepared to accomplish the optimal characteristics for bio-coating material (roughness, purity, uniformity) and then evaluated for their ability to prevent or reduce the biofilm formation of pathogenicC.albicans(SC5314) under conditions mimicking human body. Optimized DLC was synthesized via chemical vapor deposition, and then the film was characterized by Raman spectroscopy, scan electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). The potential biofilms on DLC, silicon substrate and positive control (polyvinyl chloride-PVC) were quantified via colorimetric cell viability assay (XTT); as intact and vortexed biofilms. The characteristics of formed biofilms were carried out using confocal scanning laser microscopy (CSLM) and scan electron microscope (SEM). The result showed that DLC was successfully deposited on the silicon substrate with a root mean square (RMS) roughness of 0.183± 0.09 nm. The biofilm efficaciously grown on all samples (DLC and positive control) with thickness of 46.8 ± 6.97 μm and 42.18 ± 4.65 μm, respectively. No topological and morphological changes have been observed by SEM on biofilm-DLC compared to PVC-biofilm. Moreover, all results indicated that the hydrophobicity and roughness of DLC appeared to support the attachment and the growth ofC.albicans.In conclusion , there is no privilege of utilizing DLC over PVC in term of reduction or inhibition ofC.albicansbiofilm formation at physiological conditions. Furthermore, this study may serve as an experimental model to evaluate the potential effect of nanomaterials coating on biofilm formation at conditions mimicking human’s body.

Virus-Derived Peptides for Clinical Applications

Novel affinity agents with high specificity are needed to make progress in disease diagnosis and therapy. Over the last several years, peptides have been considered to have fundamental benefits over other affinity agents, such as antibodies, due to their fast blood clearance, low immunogenicity, rapid tissue penetration, and reproducible chemical synthesis. These features make peptides ideal affinity agents for applications in disease diagnostics and therapeutics for a wide variety of afflictions. Virus-derived peptide techniques provide a rapid, robust, and high-throughput way to identify organism-targeting peptides with high affinity and selectivity. Here, we will review viral peptide display techniques, how these techniques have been utilized to select new organism-targeting peptides, and their numerous biomedical applications with an emphasis on targeted imaging, diagnosis, and therapeutic techniques. In the future, these virus-derived peptides may be used as common diagnosis and therapeutics tools in local clinics.