Tumor-coated cells train T cells in lab tests, slow tumors in mice

A piece of a patient’s tumor becomes the lesson plan. At the University of California, San Francisco, researchers coated lab-made immune cells with tiny fragments of tumor membrane, then used them to train T cells to recognize and kill cancer in laboratory tests. The same approach slowed tumor growth in mice.

The cells doing the teaching are dendritic cells, rare immune cells that normally prepare T cells for an attack. UCSF’s team made them from induced pluripotent stem cells, or iPSCs—cells that can be multiplied in the laboratory and then prompted to mature into another cell type. Because ordinary iPSCs could be rejected by the immune system, the researchers first removed their identifying information before turning them into dendritic cells.

The final step supplied the cancer-specific lesson. Tumor-cell membranes were broken into tiny bubbles that merged with the dendritic cells, covering them with a broad collection of the patient’s cancer signals rather than a single target. The dressed cells also delivered the instructions T cells need to interpret those signals as a threat. Researchers tested the method with tumor samples and T cells from patients with leukemia and ovarian cancer; the trained T cells killed tumors from the same patient in laboratory dishes.

And then what, concretely? The work suggests a possible post-surgery treatment: tissue removed during an operation could provide the tumor fragments used to prepare a personalized immune-cell therapy, with the aim of attacking cancer cells left in the body. That could matter for patients whose tumors are removed but remain at risk of returning. For now, the evidence comes from laboratory experiments and a mouse model. The evidence comes from laboratory experiments and a mouse model, and the findings still need to be tested in people.