A dendritic cell vaccine increases the breadth and diversity of melanoma neoantigen-specific T cells

Giving antitumor T cells a boost Mutations allow tumors to divide, escape death, and resist treatment. But mutations can also cause tumors to express mutant proteins, which could potentially be exploited to drive antitumor T cell responses. Carreno et al. report the results of a small phase I trial seeking to do just this (see the Perspective by Delamarre et al. ). They vaccinated three patients with advanced melanoma with personalized dendritic cell–based vaccines designed to activate T cells specific for mutations in the patients' cancer. T cells specific for mutant peptides did indeed expand. A next step will be to determine whether this promising strategy improves patient outcomes. Science , this issue p. 803 ; see also p. 760