Reprogramming immune cells inside the body

Where it stands as of Nov 9, 2026

MIT researchers built fat-based nanoparticles that carry messenger RNA into natural killer cells inside the body, and in mice the resulting CAR NK cells eliminated tumors made of cancerous T cells and reversed liver damage in a model of autoimmune hepatitis. The FDA has approved seven CAR T therapies in the past decade, all made by the slower take-out-and-return route. No human has received the in-body approach, and it is not known whether the particles can reach and reprogram enough cells in larger animals.