New mRNA cancer vaccine targets lymph nodes for stronger immune response

Researchers at Tufts University have created a new mRNA vaccine for cancer that’s designed to carry its cargo to the lymph nodes rather than the liver. Tests in mice showed significant inhibition of the tumors, with the cancer disappearing completely in a decent percentage of cases.

Development on these therapies has greatly accelerated in recent years, thanks largely to the COVID-19 pandemic. The breakthrough is now opening up the possibility of mRNA therapies for a range of other diseases, including HIV, influenza, malaria, Lyme disease, herpes, shingles, or even to repair heart tissue after a heart attack.

Perhaps the most exciting target, however, is cancer. In this case, mRNA isn’t so much a preventative vaccine but a therapeutic one, administered to cancer patients to treat existing tumors and protect against recurrence or metastasis. Trials have shown the technology could pair well with other treatments like immunotherapy.

For the new study, the Tufts researchers investigated ways to improve the immune response by changing where the mRNA ends up in the body. The team says that in most cases, the mRNA tends to end up in the liver, but a more effective immune response would be produced by sending the molecules to the lymphatic system, where immune cells are directly trained to recognize intruders.

To do so, the scientists tweaked the recipe for the lipid nanoparticles that transport the mRNA. This causes different molecules from the bloodstream to gather on the surface of the particles, which in turn bind to receptors in different organs. After testing a few combinations of properties, the team created lipid nanoparticles that favored delivery to the lymph nodes over the liver by a three-to-one ratio.

Image source: CFCF / Wikimedia Commons.