Targeting lymphatic system, cancer vaccine eliminates and prevents tumor recurrence

For years, researchers around the world have been working to develop vaccines against different types of cancer, with little succes.

The cancer vaccine works similar to the COVID vaccine from Pfizer and Moderna, delivering mRNA through tiny lipid bubbles that eventually fuse with cells in the body, allowing the cells to "read" the mRNA and produce viral antigens, which activate the immune syste.

Cancer vaccines also deliver mRNA through tiny bubbles, but mRNA encodes antigens found in cancer cells, and these bubbles, called lipid nanoparticles, can target the lymphatic system -- where immune cells are "trained" -- and therefore respond significantly more vali.

"What we are doing now is using lipid nanoparticle delivery technology to develop next-generation mRNA vaccines with the ability to target specific organs and tissues," said Qiaobing Xu, a professor of biomedical engineerin.

So far, more than 20 mRNA cancer vaccines have been included in clinical trials, but usually most of the mRNA ends up in the live.

Xu and his team previously designed lipid nanoparticles (LNPs) to target gene-editing packages in the brain and liver, as well as gene therapy in the lungs, to reverse the genetic condition in mouse model.

The study found that the LNPs currently used in Pfizer's COVID-19 vaccine favor delivery to the liver and lymphatic system in a ratio of four to on.

The lymphatic system, including our familiar lymph nodes, which often swell during infection, is an important target for vaccines because there, we acquire immunity to foreign antigens, or in this case, cancer antigen.

A key element of this training is the involvement of dendritic cells and macrophages, which are the "training sergeants" of the immune system, introducing antigens to T and B cells and helping them activat.

As more vaccine entered the lymph nodes, the Tufts researchers found that about one-third of the dendritic cells and macrophages took up the cancer vaccin.

That's exactly what the researchers foun.

"Cancer vaccines have been a challenge because tumor antigens don't always look as 'foreign' as antigens on viruses and bacteria, and tumors can actively suppress immune responses," said Jinjin Chen, a postdoctoral researcher at Tufts Universit.

Lipid nanoparticle-mediated lymph node–targeting delivery of mRNA cancer vaccine elicits robust CD8+ T cell response