Splicing Patterns in SF3B1-Mutated Uveal Melanoma Generate Shared Immunogenic Tumor-Specific Neoepitopes

Nom de la revue
Cancer Discovery
Jeremy Bigot, Ana I. Lalanne, Francesca Lucibello, Paul Gueguen, Alexandre Houy, Stephane Dayot, Olivier Ganier, Jules Gilet, Jimena Tosello, Fariba Nemati, Gaelle Pierron, Joshua J. Waterfall, Raymond Barnhill, Sophie Gardrat, Sophie Piperno-Neumann, Tatiana Popova, Vanessa Masson, Damarys Loew, Pascale Mariani, Nathalie Cassoux, Sebastian Amigorena, Manuel Rodrigues, Samar Alsafadi, Marc-Henri Stern, Olivier Lantz


Disruption of splicing patterns due to mutations of genes coding splicing factors in tumors represents a potential source of tumor neoantigens, which would be both public (shared between patients) and tumor-specific (not expressed in normal tissues). In this study, we show that mutations of the splicing factor SF3B1 in uveal melanoma generate such immunogenic neoantigens. Memory CD8+ T cells specific for these neoantigens are preferentially found in 20% of patients with uveal melanoma bearing SF3B1-mutated tumors. Single-cell analyses of neoepitope-specific T cells from the blood identified large clonal T-cell expansions, with distinct effector transcription patterns. Some of these expanded T-cell receptors are also present in the corresponding tumors. CD8+ T-cell clones specific for the neoepitopes specifically recognize and kill SF3B1-mutated tumor cells, supporting the use of this new family of neoantigens as therapeutic targets.

Mutations of the splicing factor SF3B1 in uveal melanoma generate shared neoantigens that are uniquely expressed by tumor cells, leading to recognition and killing by specific CD8 T cells. Mutations in splicing factors can be sources of new therapeutic strategies applicable to diverse tumors.
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