三阴乳腺癌（TNBC）占所有乳腺肿瘤的约20％，具有高转移倾向和不良预后。由于与其他乳腺癌类型相比，TNBC显示出较高的突变负荷，基于新抗原的免疫疗法策略可能是有效的。针对TNBC开发基于新抗原疫苗的一个重要瓶颈是选择最佳靶标，即仅在肿瘤细胞表面呈现且能够引起强烈免疫反应的肿瘤特异性新抗原。本研究旨在建立一个使用根据溶瘤天花病毒（VV）进行TNBC免疫原识别和输送的平台。我们使用生物信息学工具和基于细胞的实验来识别TNBC患者样本、人类和小鼠细胞系中的免疫原新抗原。免疫原的免疫原性在体外（人类）和体外（小鼠）T细胞实验中进行测试。为评估我们的方案的疗效，我们使用一种TNBC的临床前模型，在其中将携带肿瘤的小鼠与新抗原一起治疗，并评估对诱导新抗原特异性CD8+T细胞、肿瘤生长和生存的影响。我们成功地鉴定了免疫原新抗原，并产生了能够识别表达突变基因的人类TNBC细胞系的新抗原特异性CD8+T细胞。在一个TNBC的临床前模型中，我们展示了我们的肿瘤特异性溶瘤天花病毒能够改变肿瘤微环境，吸引和维持成熟的交叉呈递CD8α+树突状细胞和效应T细胞。此外，当与溶瘤天花病毒一起以主/辅助方案输送时，涵盖新抗原的长肽能够诱导新抗原特异性CD8+T细胞，减缓肿瘤生长并增加生存时间。我们的研究为开发基于新抗原的TNBC免疫疗法提供了一种有希望的方法。通过识别免疫原新抗原并开发通过肿瘤特异性溶瘤天花病毒进行输送的系统，我们证明基于新抗原的疫苗可以在诱导新抗原特异性CD8+T细胞反应方面具有显著影响。进一步的研究需要确定该方法在临床试验中的安全性和有效性。©作者（或其雇主）2023。在CC BY下获得再使用。BMJ出版。

Triple-negative breast cancer (TNBC) corresponds to approximately 20% of all breast tumors, with a high propensity for metastasis and a poor prognosis. Because TNBC displays a high mutational load compared with other breast cancer types, a neoantigen-based immunotherapy strategy could be effective. One major bottleneck in the development of a neoantigen-based vaccine for TNBC is the selection of the best targets, that is, tumor-specific neoantigens which are presented at the surface of tumor cells and capable of eliciting robust immune responses. In this study, we aimed to set up a platform for identification and delivery of immunogenic neoantigens in a vaccine regimen for TNBC using oncolytic vaccinia virus (VV).We used bioinformatic tools and cell-based assays to identify immunogenic neoantigens in TNBC patients' samples, human and murine cell lines. Immunogenicity of the neoantigens was tested in vitro (human) and ex vivo (murine) in T-cell assays. To assess the efficacy of our regimen, we used a preclinical model of TNBC where we treated tumor-bearing mice with neoantigens together with oncolytic VV and evaluated the effect on induction of neoantigen-specific CD8+T cells, tumor growth and survival.We successfully identified immunogenic neoantigens and generated neoantigen-specific CD8+T cells capable of recognizing a human TNBC cell line expressing the mutated gene. Using a preclinical model of TNBC, we showed that our tumor-specific oncolytic VV was able to change the tumor microenvironment, attracting and maintaining mature cross-presenting CD8α+dendritic cells and effector T-cells. Moreover, when delivered in a prime/boost regimen together with oncolytic VV, long peptides encompassing neoantigens were able to induce neoantigen-specific CD8+T cells, slow tumor growth and increase survival.Our study provides a promising approach for the development of neoantigen-based immunotherapies for TNBC. By identifying immunogenic neoantigens and developing a delivery system through tumor-specific oncolytic VV, we have demonstrated that neoantigen-based vaccines could be effective in inducing neoantigen-specific CD8+T cells response with significant impact on tumor growth. Further studies are needed to determine the safety and efficacy of this approach in clinical trials.© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.