Part 1/15 : Bacteriophages and the Immune System: How Immunity Can Shape the Success or Failure of Phage Therapy
For decades, phage therapy has been described through an apparently straightforward biological relationship. A bacteriophage encounters a susceptible bacterium, recognizes a surface receptor, injects its genome, replicates and eventually destroys its host. When translated into therapeutic language, the reasoning seems almost equally simple: identify a phage capable of lysing the pathogen and administer enough viral particles to control the infection. The reality inside the human body is considerably less linear. A therapeutic bacteriophage does not move through an empty vessel containing only its bacterial host. From the moment it is administered, it encounters epithelial barriers, mucus, soluble proteins, circulating antibodies, phagocytic cells and highly organized innate and adaptive immune networks. At the same time, the bacterial population itself is changing under the combined pressure of viral predation and host immunity. Phage therapy is therefore not fundamentally a two-player...