Eric Topol, on Ground Truths, does a dive into the history of our understanding of what bacteria has to do with cancer – from the old dogma that “cancer tumors are sterile” to research this April that bacteria can be used to elicit a T-cell response that eliminates tumor cells:
Akin to my recent post of discovering a better-than-natural antigen with RSV or SARS-CoV-2 for vaccines, this is about manipulating the genome of a skin bacterium (Staphylococcus epidermidis) to make antigens that elicit a potent T cell response against melanoma. These enhanced T cells were capable of migrating to distant skin melanoma graft sites well beneath and beyond the skin, including the metastases in the lung, with a very strong anti-tumor killing property—without causing inflammation. Notably, this approach did not result in infections, did not require intratumor delivery, and appeared to be synergic (more than additive) with immune checkpoint therapy. … This can be seen as a potential new means of immunotherapy for cancer and more broadly a novel pathway to modulate our immune response.
You can read more of the T-cell research here, in Science.