Human cancers contain genetic mutations that are unique to each patient. Some of the mutated peptides are immunogenic, can be recognized by T cells, and therefore, may serve as therapeutic targets.
Scientists at the National Cancer Institute's Surgery Branch developed a method to identify T cells that specifically recognize immunogenic mutations expressed only by cancer cells. The scientists identified cancer-specific mutations from a patient with widely metastatic cholangiocarcinoma by sequencing tumor samples and comparing with normal cells. Using tandem minigene constructs encoding all of the mutations expressed by a patient's tumor, the inventors identified T cells that recognized the immunogenic mutations from the same patient. These mutation-reactive T cells have the potential to eliminate the cancer cells while sparing normal tissues since normal tissues do not express the mutations. The mutation-reactive T cells were expanded in vitro, and then infused as a highly pure population back into the same patient. The patient experienced tumor regression when treated with this approach.