Principles bacterial immunotherapy

Bacterial immunotherapy treatment consists of (locally) administering bacterial products to an affected cancer patient with the goal of triggering an immune response against both the bacteria as well as cancer cells. 

The working mechanism of for instance BCG treatment for bladder cancer is complex and involves both the innate and adaptive immune systems. Important constituents of the immune response to BCG include so-called CD4+ and CD8+ lymphocytes, natural killer cells, and granulocytes as well as TRAIL (tumour necrosis factor-related apoptosis-inducing ligand), IL-2, IL-8, IL-18, IL-12, interferon (IFN)-γ, and tumour necrosis factor (TNF).

Just as individual patients will respond differently to a given pathogen, the mechanism of action of bacterial immunotherapy is expected to vary depending on a patient’s own immune machinery and the characteristics of his/her tumour.