The effect of bacteriophages T4 and HAP1 on in vitro melanoma migration

The Inovirus Pf4 Triggers Antiviral Responses and Disrupts the Proliferation of Airway Basal Epithelial Cells

BACKGROUND

The inovirus Pf4 is a lysogenic bacteriophage of Pseudomonas aeruginosa (Pa). People with Cystic Fibrosis (pwCF) experience chronic airway infection with Pa and a significant proportion have high numbers of Pf4 in their airway secretions. Given the known severe damage in the airways of Pa-infected pwCF, we hypothesized a high Pf4 burden can affect airway healing and inflammatory responses. In the airway, basal epithelial cells (BCs) are a multipotent stem cell population critical to epithelium homeostasis and repair. We sought to investigate the transcriptional responses of BCs under conditions that emulate infection with Pa and exposure to high Pf4 burden.

METHODS

Primary BCs isolated from pwCF and wild-type (WT) donors were cultured in vitro and exposed to Pf4 or bacterial Lipopolysaccharide (LPS) followed by transcriptomic and functional assays.

RESULTS

We found that BCs internalized Pf4 and this elicits a strong antiviral response as well as neutrophil chemokine production. Further, we found that BCs that take up Pf4 demonstrate defective migration and proliferation.

CONCLUSIONS

Our findings are highly suggestive of Pf4 playing a role in the pathogenicity of Pa in the airways. These findings provide additional evidence for the ability of inoviruses to interact with mammalian cells and disrupt cell function.

A Mammalian Cell's Guide on How to Process a Bacteriophage

Bacteriophages are enigmatic entities that defy definition. Classically, they are specialist viruses that exclusively parasitize bacterial hosts. Yet this definition becomes limiting when we consider their ubiquity in the body coupled with their vast capacity to directly interact with the mammalian host. While phages certainly do not infect nor replicate within mammalian cells, they do interact with and gain unfettered access to the eukaryotic cell structure. With the growing appreciation for the human virome, coupled with our increased application of phages to patients within clinical settings, the potential impact of phage-mammalian interactions is progressively recognized. In this review, we provide a detailed mechanistic overview of how phages interact with the mammalian cell surface, the processes through which said phages are internalized by the cell, and the intracellular processing and fate of the phages. We then summarize the current state-of-the-field with respect to phage-mammalian interactions and their associations with health and disease states.

Bacterial RNA virus MS2 exposure increases the expression of cancer progression genes in the LNCaP prostate cancer cell line

Bacteriophages effectively counteract diverse bacterial infections, and their ability to treat most types of cancer has been explored using phage engineering or phage-virus hybrid platforms. In the present study, it was demonstrated that the bacteriophage MS2 can affect the expression of genes associated with the proliferation and survival of LNCaP prostate epithelial cells. LNCaP cells were exposed to bacteriophage MS2 at a concentration of 1×10⁷ plaque forming units/ml for 24-48 h. After exposure, various cellular parameters, including cell viability, morphology, and changes in gene expression, were examined. MS2 affected cell viability adversely, reducing viability by 25% in the first 4 h of treatment; however, cell viability recovered within 24-48 h. Similarly, the AKT, androgen receptor, integrin α5, integrin β1, MAPK1, MAPK3, STAT3, and peroxisome proliferator-activated receptor-γ coactivator 1α genes, which are involved in various normal cellular processes and tumor progression, were significantly upregulated, whereas the expression levels of HSP90, ITGB5, ITGB3, HSP27, ITGAV, and PI3K genes were unchanged. Therefore, based on viability and gene expression changes, bacteriophage MS2 severely impaired LNCaP cells by reducing anchorage-dependent survival and androgen signaling. A caveolin-mediated endocytosis mechanism for MS2-mediated signaling in prostate cancer cells was proposed based on reports involving bacteriophages T4, M13, and MS2, and their interactions with LNCaP and PC3 cell lines.

Exposure to Bacteriophages T4 and M13 Increases Integrin Gene Expression and Impairs Migration of Human PC-3 Prostate Cancer Cells

The interaction between bacteriophages and integrins has been reported in different cancer cell lines, and efforts have been undertaken to understand these interactions in tumor cells along with their possible role in gene alterations, with the aim to develop new cancer therapies. Here, we report that the non-specific interaction of T4 and M13 bacteriophages with human PC-3 cells results in differential migration and varied expression of different integrins. PC-3 tumor cells (at 70% confluence) were exposed to 1 × 10⁷ pfu/mL of either lytic T4 bacteriophage or filamentous M13 bacteriophage. After 24 h of exposure, cells were processed for a histochemical analysis, wound-healing migration assay, and gene expression profile using quantitative real-time PCR (qPCR). qPCR was performed to analyze the expression profiles of integrins ITGAV, ITGA5, ITGB1, ITGB3, and ITGB5. Our findings revealed that PC-3 cells interacted with T4 and M13 bacteriophages, with significant upregulation of ITGAV, ITGA5, ITGB3, ITGB5 genes after phage exposure. PC-3 cells also exhibited reduced migration activity when exposed to either T4 or M13 phages. These results suggest that wildtype bacteriophages interact non-specifically with PC-3 cells, thereby modulating the expression of integrin genes and affecting cell migration. Therefore, bacteriophages have future potential applications in anticancer therapies.

Bacteriophages M13 and T4 Increase the Expression of Anchorage-Dependent Survival Pathway Genes and Down Regulate Androgen Receptor Expression in LNCaP Prostate Cell Line

Wild-type or engineered bacteriophages have been reported as therapeutic agents in the treatment of several types of diseases, including cancer. They might be used either as naked phages or as carriers of antitumor molecules. Here, we evaluate the role of bacteriophages M13 and T4 in modulating the expression of genes related to cell adhesion, growth, and survival in the androgen-responsive LNCaP prostatic adenocarcinoma-derived epithelial cell line. LNCaP cells were exposed to either bacteriophage M13 or T4 at a concentration of 1 × 10⁵ pfu/mL, 1 × 10⁶ pfu/mL, and 1 × 10⁷ pfu/mL for 24, 48, and 72 h. After exposure, cells were processed for general morphology, cell viability assay, and gene expression analyses. Neither M13 nor T4 exposure altered cellular morphology, but both decreased the MTT reduction capacity of LNCaP cells at different times of treatment. In addition, genes AKT, ITGA5, ITGB1, ITGB3, ITGB5, MAPK3, and PI3K were significantly up-regulated, whilst the genes AR, HSPB1, ITGAV, and PGC1A were down-regulated. Our results show that bacteriophage M13 and T4 interact with LNCaP cells and effectively promote gene expression changes related to anchorage-dependent survival and androgen signaling. In conclusion, phage therapy may increase the response of PCa treatment with PI3K/AKT pathway inhibitors.

Interactions of Bacteriophages with Animal and Human Organisms-Safety Issues in the Light of Phage Therapy

Bacteriophages are viruses infecting bacterial cells. Since there is a lack of specific receptors for bacteriophages on eukaryotic cells, these viruses were for a long time considered to be neutral to animals and humans. However, studies of recent years provided clear evidence that bacteriophages can interact with eukaryotic cells, significantly influencing the functions of tissues, organs, and systems of mammals, including humans. In this review article, we summarize and discuss recent discoveries in the field of interactions of phages with animal and human organisms. Possibilities of penetration of bacteriophages into eukaryotic cells, tissues, and organs are discussed, and evidence of the effects of phages on functions of the immune system, respiratory system, central nervous system, gastrointestinal system, urinary tract, and reproductive system are presented and discussed. Modulations of cancer cells by bacteriophages are indicated. Direct and indirect effects of virulent and temperate phages are discussed. We conclude that interactions of bacteriophages with animal and human organisms are robust, and they must be taken under consideration when using these viruses in medicine, especially in phage therapy, and in biotechnological applications.

Cell-specific targeting by engineered M13 bacteriophage expressing VEGFR2 nanobody

Objectives

Filamentous bacteriophage M13 was genetically engineered to specifically target mammalian cells for gene delivery purpose.

Materials and Methods

A vascular endothelial growth factor receptor 2 (VEGFR2)-specific nanobody was genetically fused to the capsid gene III of M13 bacteriophage (pHEN4/3VGR19). A mammalian expression construct containing Cop-green fluorescent protein (Cop-GFP), as a reporter gene, was amplified by PCR and then sub-cloned in the pHEN4/3VGR19 phagemid. The resulting construct was transfected into 293KDR cell. The recombinant phage was extracted and confirmed and then transduced into VEGFR2 expressing cell (293KDR).

Results

Seventy-two hr after transfection, green fluorescence was detected in 30% of the cells. About 1% of the cells which transduced by recombinant phages were able to express GFP.

Conclusion

It is hoped that the results from this study will help to find potential vectors to improve the efficiency of gene delivery. Taken together, we conclude that this newly-introduced vector can be used in cancer researches.

Development of pipette tip gap closure migration assay (s-ARU method) for studying semi-adherent cell lines

This work presents a pipette tip gap closure migration assay prototype tool (semi-adherent relative upsurge-s-ARU-method) to study cell migration or wound healing in semi-adherent cell lines, such as lymph node carcinoma of the prostate (LNCaP). Basically, it consists of a 6-well cover plate modification, where pipette tips with the filter are shortened and fixed vertically to the inner surface of the cover plate, with their heights adjusted to touch the bottom of the well center. This provides a barrier for the inoculated cells to grow on, creating a cell-free gap. Such a uniform gap formed can be used to study migration assay for both adherent as well as semi-adherent cells. After performing time studies, effective measurement of gap area can be carried out conveniently through image analysis software. Here, the prototype was tested for LNCaP cells, treated with testosterone and flutamide as well as with bacteriophages T4 and M13. A scratch assay using PC3 adherent cells was also performed for comparison. It was observed that s-ARU method is suitable for studying LNCaP cells migration assay, as observed from our results with testosterone, flutamide, and bacteriophages (T4 and M13). Our method is a low-cost handmade prototype, which can be an alternative to the other migration assay protocol(s) for both adherent and semi-adherent cell cultures in oncological research along with other biological research applications.

Characterization of the bacteriophages binding to human matrix molecules

Recent literature has suggested a novel symbiotic relationship between bacteriophage and metazoan host that provides antimicrobial defense protecting mucosal surface by binding to host matrix mucin glycoproteins. Here, we isolated and studied different bacteriophages that specifically interact with human extracellular matrix molecules such as fibronectin, gelatin, heparin and demonstrated their potency for protection to host against microbial infections. We showed that subpopulations of bacteriophages that work against clinical isolates of Escherichia coli can bind to pure gelatin, fibronectin and heparin and reduced bacterial load in human colon cell line HT29. The bacteriophages were characterized with respect to their genome sizes, melting curve patterns and host tropism (cross-reactivity with different hosts). Since, the bacteriophages are non-toxic to the host and can effectively reduce bacterial load in HT29 cell line their therapeutic potency against bacterial infection could be explored.

Phages and immunomodulation

In the past years, the microbiome and its role in the pathophysiology of diseases have gained great interest. The progress of our knowledge in this field opens completely novel prospects for treating disorders, including those which are most challenging to medicine today. Of special interest are studies on the interactions of the microbiome with the immune system. Only recently has the presence of bacteriophages in the microbiome been highlighted, and their potential role in maintaining normal immunity has gained increasing attention. We summarize the available data pointing to the potential impact of phages in maintaining immunological homeostasis.

Facing antibiotic resistance: Staphylococcus aureus phages as a medical tool

Staphylococcus aureus is a common and often virulent pathogen in humans. This bacterium is widespread, being present on the skin and in the nose of healthy people. Staphylococcus aureus can cause infections with severe outcomes ranging from pustules to sepsis and death. The introduction of antibiotics led to a general belief that the problem of bacterial infections would be solved. Nonetheless, pathogens including staphylococci have evolved mechanisms of drug resistance. Among current attempts to address this problem, phage therapy offers a promising alternative to combat staphylococcal infections. Here, we present an overview of current knowledge on staphylococcal infections and bacteriophages able to kill Staphylococcus, including experimental studies and available data on their clinical use.

Bacteriophages and cancer

Bacteriophages can be used effectively to cure bacterial infections. They are known to be active against bacteria but inactive against eukaryotic cells. Nevertheless, novel observations suggest that phages are not neutral for higher organisms. They can affect physiological and immunological processes which may be crucial to their expected positive effects in therapies. Bacteriophages are a very differentiated group of viruses and at least some of them can influence cancer processes. Phages may also affect the immunological system. In general, they activate the immunological response, for example cytokine secretion. They can also switch the tumor microenvironment to one advantageous for anticancer treatment. On the other hand, bacteriophages are used as a platform for foreign peptides that may induce anticancer effects. As bacterial debris can interfere with bacteriophage activity, phage purification is significant for the final effect of a phage preparation. In this review, results of the influence of bacteriophages on cancer processes are presented which have implications for the perspective application of phage therapy in patients with cancer and the general understanding of the role of bacteriophages in the human organism.