Therapeutic E. coli T4 and Staph A5/80 phages induce mild monocyte-driven cytokine response

Bacteriophage therapy is gaining traction as an alternative to antibiotics, especially with rising antimicrobial resistance. Beyond their direct lytic action against bacteria, bacteriophages are increasingly recognized for their potential as active immunomodulators. However, a detailed understanding of how these viral agents interact with the human immune system, particularly regarding cytokine production by specific immune cell populations, remains crucial. This knowledge gap is vital for assessing their broader impact on human homeostasis and ensuring their safe therapeutic application.

Researchers incubated human peripheral blood mononuclear cells (PBMCs) and isolated subpopulations (B and T lymphocytes, NK cells, monocytes) from healthy donors for 24 hours. Cells were exposed to purified Escherichia coli phage T4 and therapeutic staphylococcal phage A5/80. Control arms included LPS from E. coli B (activity-matched) and human adenovirus 5 as a benchmark. The study assessed the secretion of 11 cytokines, including IFN-γ, IL-6, TNF-α, and IL-10, via implied multiplex immunoassay.