Bacteriophage: from bacteria to targeted gene delivery to mammalian cells

Bacteriophage (phage), bacterial viruses, have been improved as non-human pathogenic viral vectors for the purpose of introducing genetic materials into mammalian cells. Previously, our group generated a novel Adeno-associated virus/Phage (AAVP) hybrid vector as a valuable tool for targeted gene transfer to mammalian cells. However, the efficacy of bacteriophage-based vectors is considered relatively poor, meaning that ways of improving it are of considerable interest. First approach to improve AAVP-mediated gene delivery is through chemical modification. We showed that the transduction efficiency of AAVP was increased by the complexation of phage vectors with cationic molecules and calcium phosphate co-precipitation. Application of the bacteriophage complex carrying a cytotoxic gene resulted in eradication of cultured brain tumour cells. The chemically modified vector showed superior gene delivery over the conventional vector and can thus be regarded as an improved version of phage-based vector that has promise in cancer gene therapy. Next, we demonstrated that Extracellular Matrix (ECM) presents an obstacle for AAVP. Using brain cancer cell lines as a model, AAVP transduction was significantly increased by collagenase and hyaluronidase-mediated degradation of ECM, which can subsequently be translated into tumour cell eradication through AAVP-mediated gene therapy. Our findings prove that combination of AAVP vectors with ECM depletion represents a powerful strategy to advance phage- guided gene transfer. Finally, we engineered the prototype bacteriophage-based multifunctional vector as a proof-of-concept model that can simultaneously display three different peptides and carry a mammalian transgene cassette. Our results show that bacteriophage can be used as a scaffold for constructing multifunctional carriers that integrate multiple functions, which may have great potential for gene delivery applications. Together, the data demonstrate the potential for improved AAVP-based gene transfer to mammalian cells focusing on the use of chemical modification, manipulation of ECM, and the generation of multifunctional phage vectors.Open Acces

Effects of alpha-mangostin encapsulated in nanostructured lipid carriers in mice with cerebral ischemia reperfusion injury

Cerebral ischemia reperfusion injury (CIRI) is a phenomenon in which the cerebral blood supply is restored after a period of ischemia, resulting in irreversible damage to brain tissue. Oxidative stress plays a crucial role in the development of CIRI, therefore, targeting oxidative stress might be an effective strategy for CIRI prevention and treatment. Many therapeutic substances possess antioxidant and protective properties against neurodegenerative disorders but lack of in vivo application due to their solubility, and bioavailability. We investigated the effects of alpha-mangostin (αM) encapsulated in nanostructured lipid carriers (αM-NLC) on CIRI in mice. Forty male ICR mice were randomly divided into four groups: Sham, ischemia reperfusion (IR), ischemia reperfusion with 25 mg/kg of αM (IR+αM), and ischemia reperfusion with 25 mg/kg of αM-NLC (IR+αM-NLC). After 6 days of oral administrations, IR was delivered using 30 min of bilateral common carotid artery occlusion, followed by 45 min of reperfusion. Cerebral infarction volume, hippocampal neuronal and corpus callosum (CC) white matter damage, malondialdehyde (MDA) level, and catalase (CAT) activity were evaluated. Our results indicated that αM and αM-NLC prevent lipid peroxidation as well as hippocampal CA1, CA3, and CC damage (p<0.05). Only αM-NLC prevented cerebral infarction and enhanced CAT activity (p<0.05). We therefore conclude that αM and αM-NLC have neuroprotective effects against CIRI, and NLC increases therapeutic efficacy of αM against CIRI

Surface modification of gold nanoparticles with neuron-targeted exosome for enhanced blood–brain barrier penetration

Gold nanoparticles (AuNPs) have been extensively used as nanomaterials for theranostic applications due to their multifunctional characteristics in therapeutics, imaging, and surface modification. In this study, the unique functionalities of exosome-derived membranes were combined with synthetic AuNPs for targeted delivery to brain cells. Here, we report the surface modification of AuNPs with brain-targeted exosomes derived from genetically engineered mammalian cells by using the mechanical method or extrusion to create these novel nanomaterials. The unique targeting properties of the AuNPs after fabrication with the brain-targeted exosomes was demonstrated by their binding to brain cells under laminar flow conditions as well as their enhanced transport across the blood brain barrier. In a further demonstration of their ability to target brain cells, in vivo bioluminescence imaging revealed that targeted-exosome coated AuNPs accumulated in the mouse brain after intravenous injection. The surface modification of synthetic AuNPs with the brain-targeted exosome demonstrated in this work represents a highly novel and effective strategy to provide efficient brain targeting and shows promise for the future in using modified AuNPs to penetrate the brain

Next-generation of targeted AAVP vectors for systemic transgene delivery against cancer

Bacteriophage (phage) have attractive advantages as delivery sys-tems compared to mammalian viruses, but have been consideredpoor vectors because they lack evolved strategies to confrontand overcome mammalian cell barriers to infective agents. Wereasoned that improved efficacy of delivery might be achievedthrough structural modification of the viral capsid to avoid pre-and post-internalization barriers to mammalian cell transduction.We generated multifunctional hybrid AAV/phage (AAVP) particlesto enable simultaneous display of targeting ligands on the phage’sminor pIII proteins and also degradation-resistance motifs on thevery numerous pVIII coat proteins. This genetic strategy of directedevolution, bestows a next-generation of AAVP particles that fea-ture resistance to fibrinogen adsorption or neutralizing antibodies,and ability to escape endolysosomal degradation. This results insuperior gene transfer efficacyin vitroand also in preclinicalmouse models of rodent and human solid tumors. Thus, the uniquefunctions of our next-generation AAVP particles enable improvedtargeted gene delivery to tumor cells

Inhibition of Histone Deacetylation and DNA Methylation Improves Gene Expression Mediated by the Adeno-Associated Virus/Phage in Cancer Cells

Bacteriophage (phage), viruses that infect bacteria only, have become promising vectors for targeted systemic delivery of genes to cancer, although, with poor efficiency. We previously designed an improved phage vector by incorporating cis genetic elements of adeno-associated virus (AAV). This novel AAV/phage hybrid (AAVP) specifically targeted systemic delivery of therapeutic genes into tumors. To advance the AAVP vector, we recently introduced the stress-inducible Grp78 tumor specific promoter and found that this dual tumor-targeted AAVP provides persistent gene expression, over time, in cancer cells compared to silenced gene expression from the CMV promoter in the parental AAVP. Herein, we investigated the effect of histone deacetylation and DNA methylation on AAVP-mediated gene expression in cancer cells and explored the effect of cell confluence state on AAVP gene expression efficacy. Using a combination of AAVP expressing the GFP reporter gene, flow cytometry, inhibitors of histone deacetylation, and DNA methylation, we have demonstrated that histone deacetylation and DNA methylation are associated with silencing of gene expression from the CMV promoter in the parental AAVP. Importantly, inhibitors of histone deacetylases boost gene expression in cancer cells from the Grp78 promoter in the dual tumor-targeted AAVP. However, cell confluence had no effect on AAVP-guided gene expression. Our findings prove that combination of histone deacetylase inhibitor drugs with the Grp78 promoter is an effective approach to improve AAVP-mediated gene expression in cancer cells and should be considered for AAVP-based clinical cancer gene therapy

Key Success Factors for the Development of Innovative Antibiotic Replacement Products to Accelerate Growth in Broilers

The issue of drug-resistant bacteria and the ban on antibiotic growth has encouraged research into new additives for the broiler chicken industry, from the point of view of environmental, social, governance sustainability, and material sciences management. This study aimed to examine the newest innovative antibiotic replacement products using a mixed method of planning and development schemes. Firstly, the qualitative method was conducted to evaluate the voices of 15 key users to examine product composition through an engineering technique and the quality function deployment (QFD) method. A prototype was proposed, containing a combination of nutraceuticals, including medium-chain fatty acids, short-chain fatty acids, oregano essential oil, and sweet basil essential oil, delivered in drinking water and as a feed additive through nanostructure lipid carrier (NLC) technology. The quantitative research summarized the compositions in terms of improving the growth performance of poultry, based on 280 responses. By using confirmatory factor analysis (CFA), the key factors of a successful antibiotic replacement are that they should be standardized and must follow regulations, be perceived as easy to use, satisfy performance expectations, address industry concerns, be innovative, offer an appropriate product and physical characteristics to the farm, and be presented alongside sales opportunities and marketing. It is concluded that such a hybrid of product development and innovation will lead to novel and appropriate products in the marketplace

Multiple and High-Risk Clones of Extended-Spectrum Cephalosporin-Resistant and blaNDM-5-Harbouring Uropathogenic Escherichia coli from Cats and Dogs in Thailand

Resistance to extended-spectrum cephalosporins (ESC) and carbapenems in Escherichia coli (E. coli), increasingly identified in small animals, indicates a crisis of an antimicrobial resistance situation in veterinary medicine and public health. This study aimed to characterise the genetic features of ESC-resistant E. coli isolated from cats and dogs with urinary tract infections in Thailand. Of 72 ESC-resistant E. coli isolated from diagnostic samples (2016–2018), blaCTX-M including group 1 (CTX-M-55, -15 and -173) and group 9 (CTX-M-14, -27, -65 and -90) variants were detected in 47 isolates (65.28%) using PCR and DNA sequencing. Additional antimicrobial resistance genes, including plasmid-mediated AmpC (CIT and DHA), blaNDM-5, mcr-3, mph(A) and aac(6′)-Ib-cr, were detected in these isolates. Using a broth microdilution assay, all the strains exhibited multidrug-resistant phenotypes. The phylogroups were F (36.11%), A (20.83%), B1 (19.44%), B2 (19.44%) and D (4.17%), with several virulence genes, plasmid replicons and an integrase gene. The DNA fingerprinting using a repetitive extragenic palindromic sequence-PCR presented clonal relationships within phylogroups. Multiple human-associated, high-risk ExPEC clones associated with multidrug resistance, including sequence type (ST) 38, ST131, ST224, ST167, ST354, ST410, ST617 and ST648, were identified, suggesting clonal dissemination. Dogs and cats are a potential reservoir of ESC-resistant E. coli and significant antimicrobial resistance genes

Addressing Nanovaccine Strategies for Tilapia

Tilapia is the world’s most extensively farmed species after carp. It is an attractive species for aquaculture as it grows quickly, reaching harvest size within six to seven months of production, and provides an important source of food and revenue for many low-income families, especially in low- to middle-income countries. The expansion of tilapia aquaculture has resulted in an intensification of farming systems, and this has been associated with increased disease outbreaks caused by various pathogens, mostly bacterial and viral agents. Vaccination is routinely used to control disease in higher-value finfish species, such as Atlantic salmon. At the same time, many tilapia farmers are often unwilling to vaccinate their fish by injection once the fish have been moved to their grow-out site. Alternative vaccination strategies are needed to help tilapia farmers accept and use vaccines. There is increasing interest in nanoparticle-based vaccines as alternative methods for delivering vaccines to fish, especially for oral and immersion administration. They can potentially improve vaccine efficacy through the controlled release of antigens, protecting antigens from premature proteolytic degradation in the gastric tract, and facilitating antigen uptake and processing by antigen-presenting cells. They can also allow targeted delivery of the vaccine at mucosal sites. This review provides a brief overview of the bacterial and viral diseases affecting tilapia aquaculture and vaccine strategies for farmed tilapia. It focuses on the use of nanovaccines to improve the acceptance and uptake of vaccines by tilapia farmers

Immersion Vaccination by a Biomimetic-Mucoadhesive Nanovaccine Induces Humoral Immune Response of Red Tilapia (<i>Oreochromis</i> sp.) against <i>Flavobacterium columnare</i> Challenge

Immersion vaccination with a biomimetic mucoadhesive nanovaccine has been shown to induce a strong mucosal immune response against columnaris disease, a serious bacterial disease in farmed red tilapia caused by Flavobacterium columnare. However, the induction of a systemic immune response by the vaccine is yet to be investigated. Here, we examine if a specific humoral immune response is stimulated in tilapia by a biomimetic-mucoadhesive nanovaccine against Flavobacterium columnare using an indirect-enzyme-linked immunosorbent assay (ELISA), serum bactericidal activity (SBA) and the expression of immune-related genes within the head-kidney and spleen, together with assessing the relative percent survival of vaccinated fish after experimentally infecting them with F. columnare. The anti-IgM antibody titer of fish at 14 and 21 days post-vaccination was significantly higher in chitosan complex nanoemulsion (CS-NE) vaccinated fish compared to fish vaccinated with the formalin-killed vaccine or control fish, supporting the serum bactericidal activity results at these time points. The cumulative mortality of the unvaccinated control fish was 87% after challenging fish with the pathogen, while the cumulative mortality of the CS-NE vaccinated group was 24%, which was significantly lower than the formalin-killed vaccinated and control fish. There was a significant upregulation of IgM, IgT, TNF α, and IL1-β genes in the spleen and kidney of vaccinated fish. Significant upregulation of IgM and IgT genes was observed in the spleen of CS-NE vaccinated fish. The study confirmed the charged-chitosan-based mucoadhesive nanovaccine to be an effective platform for immersion vaccination of tilapia, with fish generating a humoral systemic immune response against columnaris disease in vaccinated fish

Immersion Vaccination by a Biomimetic-Mucoadhesive Nanovaccine Induces Humoral Immune Response of Red Tilapia (Oreochromis sp.) against Flavobacterium columnare Challenge

Immersion vaccination with a biomimetic mucoadhesive nanovaccine has been shown to induce a strong mucosal immune response against columnaris disease, a serious bacterial disease in farmed red tilapia caused by Flavobacterium columnare. However, the induction of a systemic immune response by the vaccine is yet to be investigated. Here, we examine if a specific humoral immune response is stimulated in tilapia by a biomimetic-mucoadhesive nanovaccine against Flavobacterium columnare using an indirect-enzyme-linked immunosorbent assay (ELISA), serum bactericidal activity (SBA) and the expression of immune-related genes within the head-kidney and spleen, together with assessing the relative percent survival of vaccinated fish after experimentally infecting them with F. columnare. The anti-IgM antibody titer of fish at 14 and 21 days post-vaccination was significantly higher in chitosan complex nanoemulsion (CS-NE) vaccinated fish compared to fish vaccinated with the formalin-killed vaccine or control fish, supporting the serum bactericidal activity results at these time points. The cumulative mortality of the unvaccinated control fish was 87% after challenging fish with the pathogen, while the cumulative mortality of the CS-NE vaccinated group was 24%, which was significantly lower than the formalin-killed vaccinated and control fish. There was a significant upregulation of IgM, IgT, TNF α, and IL1-β genes in the spleen and kidney of vaccinated fish. Significant upregulation of IgM and IgT genes was observed in the spleen of CS-NE vaccinated fish. The study confirmed the charged-chitosan-based mucoadhesive nanovaccine to be an effective platform for immersion vaccination of tilapia, with fish generating a humoral systemic immune response against columnaris disease in vaccinated fish