The potential role of endogenous bacteriophages in controlling invading pathogens

Andrzej Górski1, Beata Weber-Dabrowska

  • 1L. Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53114, Wroclaw, Poland. agorski@ikp.pl

Insights

Bacteriophages (phages), viruses that infect bacteria, are found in humans and may help regulate the body

Area of Science:

  • Microbiology
  • Immunology
  • Virology

Background:

  • Bacteriophages (phages) are ubiquitous environmental microorganisms with significant ecological roles.
  • Phages reside within mammalian hosts, including humans, inhabiting various body sites like the gut and oral cavity.
  • Emerging research indicates endogenous phages may influence host health and microbial community dynamics.

Purpose of the Study:

  • To explore the potential roles of endogenous bacteriophages in mammalian systems.
  • To investigate the immunomodulatory and therapeutic capabilities of phages within the host.
  • To hypothesize the synergistic interaction between phages and the host immune system.

Main Methods:

  • Review of existing data on phage presence and function in mammals.
  • Analysis of recent findings on phage-host interactions.
  • Hypothetical modeling of phage-immune system interplay.

Main Results:

  • Endogenous phages may contribute to bacterial elimination and ecosystem regulation.
  • Phages exhibit potential immunosuppressive effects in the gut, aiding control of inflammation and autoimmunity.
  • Evidence suggests phages possess anticancer activities.

Conclusions:

  • Endogenous bacteriophages are significant components of the mammalian microbiome with diverse physiological roles.
  • Phages demonstrate potential as therapeutic agents for inflammatory, autoimmune, and cancerous conditions.
  • A hypothesis is proposed for phages collaborating with the immune system in host defense and immunosurveillance.

Related Concept Videos

Bacteriophages of the Human Virome01:23

Bacteriophages of the Human Virome

Bacteriophages are found throughout the human body. They may even outnumber eukaryotic viruses, forming an important and dynamic component of the human virome. Indeed, phages represent the most abundant viral entities, with densities in the gut reaching up to 10⁹ particles per gram of fecal matter, and many belonging to orders such as Caudovirales and Microviridae, while a substantial proportion remains unclassified as viral “dark matter.”Lysogeny and Genetic ExchangeIn the gut, bacteriophages...
Lytic Cycle of Bacteriophages01:30

Lytic Cycle of Bacteriophages

Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the lytic replication...
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
Lysogenic Cycle of Bacteriophages00:43

Lysogenic Cycle of Bacteriophages

In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
Viral Replication: Lysogenic Cycle01:16

Viral Replication: Lysogenic Cycle

The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects its...
Defense Against Bacterial Pathogens01:31

Defense Against Bacterial Pathogens

The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...