Perspectives of Phage-Eukaryotic Cell Interactions to Control Epstein-Barr Virus Infections

Bacteriophage therapy against ESKAPE bacterial pathogens: Current status, strategies, challenges, and future scope

The ESKAPE pathogens are the primary threat due to their constant spread of drug resistance worldwide. These pathogens are also regarded as opportunistic pathogens and could potentially cause nosocomial infections. Most of the ESKAPE pathogens have developed resistance to almost all the antibiotics that are used against them. Therefore, to deal with antimicrobial resistance, there is an urgent requirement for alternative non-antibiotic strategies to combat this rising issue of drug-resistant organisms. One of the promising alternatives to this scenario is implementing bacteriophage therapy. This under-explored mode of treatment in modern medicine has posed several concerns, such as preferable phages for the treatment, impact on the microbiome (or gut microflora), dose optimisation, safety, etc. The review will cover a rationale for phage therapy, clinical challenges, and propose phage therapy as an effective therapeutic against bacterial coinfections during pandemics. This review also addresses the expected uncertainties for administering the phage as a treatment against the ESKAPE pathogens and the advantages of using lytic phage over temperate, the immune response to phages, and phages in combinational therapies. The interaction between bacteria and bacteriophages in humans and countless animal models can also be used to design novel and futuristic therapeutics like personalised medicine or bacteriophages as anti-biofilm agents. Hence, this review explores different aspects of phage therapy and its potential to emerge as a frontline therapy against the ESKAPE bacterial pathogen.

Therapeutic Phages as Modulators of the Immune Response: Practical Implications

While the medical community awaits formal proof of the efficacy of phage therapy, as is required by evidence-based medicine, existing data suggest that phages could also be applied based on their non-antibacterial action, especially phage-mediated immunomodulation. Promising avenues have been revealed by findings indicating that phages may mediate diverse actions in the immune system, while the list of phages able to dampen the aberrant immunity associated with a variety of disorders continuously grows. Here we summarize what is known in this field and possible options for the future. While available data are still scarce and preliminary, it appears that "phage repurposing" is worthy of more research, which could reveal new perspectives on applying phage therapy in contemporary medicine.

Myriad applications of bacteriophages beyond phage therapy

Bacteriophages are the most abundant biological entity on the planet, having pivotal roles in bacterial ecology, animal and plant health, and in the biogeochemical cycles. Although, in principle, phages are simple entities that replicate at the expense of their bacterial hosts, due the importance of bacteria in all aspects of nature, they have the potential to influence and modify diverse processes, either in subtle or profound ways. Traditionally, the main application of bacteriophages is phage therapy, which is their utilization to combat and help to clear bacterial infections, from enteric diseases, to skin infections, chronic infections, sepsis, etc. Nevertheless, phages can also be potentially used for several other tasks, including food preservation, disinfection of surfaces, treatment of several dysbioses, and modulation of microbiomes. Phages may also be used as tools for the treatment of non-bacterial infections and pest control in agriculture; moreover, they can be used to decrease bacterial virulence and antibiotic resistance and even to combat global warming. In this review manuscript we discuss these possible applications and promote their implementation.

Clinical and experimental bacteriophage studies: Recommendations for possible approaches for standing against SARS-CoV-2

In 2019, the world faced a serious health challenge, the rapid spreading of a life-threatening viral pneumonia, coronavirus disease 2019 (COVID-19) caused by a betacoronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As of January 2022 WHO statistics shows more than 5.6 million death and about 350 million infection by SARS-CoV-2. One of the life threatening aspects of COVID-19 is secondary infections and reduced efficacy of antibiotics against them. Since the beginning of COVID-19 many researches have been done on identification, treatment, and vaccine development. Bacterial viruses (bacteriophages) could offer novel approaches to detect, treat and control COVID-19. Phage therapy and in particular using phage cocktails can be used to control or eliminate the bacterial pathogen as an alternative or complementary therapeutic agent. At the same time, phage interaction with the host immune system can regulate the inflammatory response. In addition, phage display and engineered synthetic phages can be utilized to develop new vaccines and antibodies, stimulate the immune system, and elicit a rapid and well-appropriate defense response. The emergence of SARS-CoV-2 new variants like delta and omicron has proved the urgent need for precise, efficient and novel approaches for vaccine development and virus detection techniques in which bacteriophages may be one of the plausible solutions. Therefore, phages with similar morphology and/or genetic content to that of coronaviruses can be used for ecological and epidemiological modeling of SARS-CoV-2 behavior and future generations of coronavirus, and in general new viral pathogens. This article is a comprehensive review/perspective of potential applications of bacteriophages in the fight against the present pandemic and the post-COVID era.

An Overview of Antiviral Properties of Bacteriophages with Emphasis on the Treatment of COVID-19 Infection

Bacteriophages or phages are the most abundant organisms in the biosphere. Scientists considered phages an appropriate tool for understanding molecular biology, horizontal gene transfer vectors, stimulants of bacterial evolution, a source of diagnostic and genetic tools, and new therapeutic agents. Therefore, studying the biology of phages and their interactions with their hosts is crucial to gaining a deeper knowledge of biological systems. Numerous studies confirmed that bacteriophages are a genetic tool with high potential for treating infectious diseases, including bacterial, fungal, and viral infections. Therefore, phages may be used as an appropriate therapeutic target against some viruses, such as COVID-19 infection. In this study, we describe the role of phages in modulating the host immune system, the production of specific antibodies against the COVID-19 virus by the host immune system, and the minimization of damage caused by the COVID-19 virus to the host. Also, the present study expresses our understanding of the prospect of phage therapy as an adjunctive therapy.

Transkingdom Interactions Important for the Pathogenesis of Human Viruses

The bacterial, fungal, and helminthic species that comprise the microbiome of the mammalian host have profound effects on health and disease. Pathogenic viruses must contend with the microbiome during infection and likely have evolved to exploit or evade the microbiome. Both direct interactions between the virions and the microbiota and immunomodulation and tissue remodeling caused by the microbiome alter viral pathogenesis in either host- or virus-beneficial ways. Recent insights from in vitro and murine models of viral pathogenesis have highlighted synergistic and antagonistic, direct and indirect interactions between the microbiome and pathogenic viruses. This review will focus on the transkingdom interactions between human gastrointestinal and respiratory viruses and the constituent microbiome of those tissues.

Recombinant T7 Phage with FMDV AKT-III Strain VP1 Protein is a Potential FMDV Vaccine

OBJECTIVES

The capsid protein (VP1) of the foot-and-mouth (FMD) AKT-III strain was expressed on the surface of the T7 phage capsid (AKT-T7 strain) and the potential of AKT-T7 strain as an FMD vaccine was evaluated.

RESULTS

The AKT-T7 strain was successfully constructed and was not cytotoxic to BHK-21, MDBK, or sheep kidney cells. The AKT-T7 strain was well phagocytosed by mouse macrophages. Immunization of BALB/c mice revealed that animals were quickly induced and produced high levels of FMDV antibodies. Monitoring data indicated that FMDV antibody levels could be maintained at higher levels for longer periods of time. The AKT-T7 strain induced high levels of IFN-γ levels in mice with little effect on IL-4.

CONCLUSIONS

The AKT-T7 induced the mice to produce FMDV antibodies, which has the advantage of phage and FMDV, and is a potential candidate for an FMD vaccine.

Phage penetration of eukaryotic cells: practical implications

The inability to infect eukaryotic cells has been considered as the most undeniable feature of all bacterial viruses. Such specificity, limited only for bacterial hosts, raises questions about the paths and challenges phages should overcome when circulating through the human body. Recently, it has been shown that phages are able to continually penetrate human organs and tissues. Latest reports revealed that phages can cross eukaryotic cell barriers both para- and transcellularly and even reach the nucleus. Further, phages are capable of internalizing within cells through different endocytic mechanisms. Such phenomenon indicates that phages could shape human microbiome composition and affect all aspects of human health. Thus, herein, we summarize the current state of knowledge and describe this phenomenon with a particular emphasis on endocytic pathways.

Perspectives of Phage Therapy in Non-bacterial Infections

While the true value of phage therapy (PT) in human bacterial infections still awaits formal confirmation by clinical trials, new data have been accumulating indicating that in the future PT may be applied in the treatment of non-bacterial infections. Thus, "phage guests" may interact with eukaryotic cells and such interactions with cells of the immune system may protect human health (Guglielmi, 2017) and cause clinically useful immunomodulatory and anti-inflammatory effects when administered for therapeutic purposes (Górski et al., 2017; Van Belleghem et al., 2017). Recently, a vision of how these effects could translate into advances in novel means of therapy in a variety of human pathologies secondary to immune disturbances and allergy was presented (Górski et al., 2018a). In this article we present what is currently known about anti-microbial effects of phage which are not directly related to their antibacterial action and how these findings could be applied in the future in treatment of viral and fungal infections.