T4 phage and its head surface proteins do not stimulate inflammatory mediator production

Area of Science:

• Microbiology
• Immunology
• Virology

Background:

• Viruses activate immune pathways, increasing cytokine and reactive oxygen species (ROS) production, often mediated by viral proteins.
• Understanding bacteriophage (phage) influence on mammalian immunity is vital for advancing phage therapy.
• Phage proteins could potentially mimic viral stimulators, impacting phage therapy's safety and efficacy.

Purpose of the Study:

• To investigate the immunomodulatory effects of T4 bacteriophage and its capsid proteins (gp23*, gp24*, Hoc, Soc).
• To assess the impact on inflammatory mediators, cytokines, and ROS production in mammalian systems.

Main Methods:

• Evaluated plasma cytokine profiles in a mouse model and human blood cells using cytokine antibody arrays after treatment with T4 phage and its proteins.
• Investigated cytokine production and immune cell marker expression (CD40, CD80, CD86, MHC class II) in dendritic cells exposed to T4 phage and proteins.
• Assessed ROS generation in blood cells using luminol-dependent chemiluminescence assay.

Main Results:

• T4 bacteriophage and its capsid proteins (gp23*, gp24*, Hoc, Soc) did not induce significant changes in inflammatory cytokine production.
• No notable effect on ROS generation was observed in blood cells treated with T4 phage or its proteins.
• Expression of immune cell markers on dendritic cells remained unaffected by T4 phage and its capsid proteins.

Conclusions:

• T4 bacteriophage and its purified capsid proteins do not activate inflammatory responses or ROS production in mammalian immune cells.
• These findings support the safety profile of T4 bacteriophage and its components for therapeutic applications.
• Further research into phage-host interactions is essential for optimizing phage therapy strategies.