MIT nanoparticles turn immune cells into cancer killers inside the body

Cancer immunotherapy has changed outcomes for some blood cancers, but its complexity limits who can get it. MIT researchers have now shown a way to engineer immune cells inside the body, which could make these treatments far easier to produce and deliver. The work matters for cancer and autoimmune disease, both of which become more common with age.

The team focused on natural killer (NK) cells, immune cells that can be engineered to recognize and destroy harmful cells. Instead of removing cells from a patient and modifying them in a lab, the researchers used lipid nanoparticles to carry messenger RNA directly to NK cells in the body. The RNA instructs the cells to make a chimeric antigen receptor (CAR), producing CAR NK cells that target diseased T cells. These include cancerous T cells in lymphoma and T cells that wrongly attack healthy tissue in autoimmune hepatitis.

In mouse experiments, the approach eliminated tumors and reversed liver damage. The senior author, Daniel Anderson, noted that manufacturing is a major obstacle for CAR NK therapies, and that a nanoparticle can modify a patient's own NK cells to attack tumor cells. The study was published in Nature Biotechnology.

For context, the FDA has approved seven CAR T therapies over the past decade, mainly for B-cell cancers such as leukemia, lymphoma, and multiple myeloma. Those therapies require collecting blood, shipping it to a specialized facility, isolating and modifying T cells, expanding them, and returning them to the hospital for infusion. Doing the engineering in the body could cut time, cost, and logistical burden.

Practically, nothing here is available to patients yet. The results come from mice, and human safety, dosing, durability, off-target effects, and immune reactions to the nanoparticles remain unknown. Readers should view this as a promising platform that may eventually broaden access to advanced immune therapies, not as a treatment option today.