Comprehensive mutanome analysis of Lewis lung cancer reveals immunogenic neoantigens for therapeutic vaccines

Personalized neoantigen vaccines are capable of eliciting vigorous T-cell responses and have been demonstrated to achieve striking therapeutic effects against cancer. Here we performed comprehensive mutanome analysis of the mouse Lewis lung cancer cells to identify tumor neoantigens followed by prediction of their MHC affinity and immunogenicity. We adopted a strategy that enables us to select neoantigens that were predicted to have high affinity to both MHC I and MHC II. Ten neoantigens were selected to synthesize peptide vaccines and tested in vivo for immunogenicity. Four neoantigen peptide vaccines were found to elicit robust immune reactivity and were further examined for tumor inhibition in mice with xenografted LLC tumors. Two neoantigen peptide vaccines showed significant inhibition on tumor growth and prolonged the survival of tumor-bearing mice. Our studies explored the neoantigen peptide vaccines to treat lung cancer and provide rationale for the optimization of tumor neoantigen selection for therapeutic vaccines.