{"title":"Neoantigen mRNA vaccines induce progenitor-exhausted T cells that support anti-PD-1 therapy in gastric cancer with peritoneal metastasis.","authors":"Koji Nagaoka, Hideyuki Nakanishi, Hiroki Tanaka, Jessica Anindita, Takeshi Kawamura, Toshiya Tanaka, Takefumi Yamashita, Akihiro Kuroda, Sachiyo Nomura, Hidetaka Akita, Keiji Itaka, Tatsuhiko Kodama, Kazuhiro Kakimi","doi":"10.1007/s10120-025-01640-8","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Gastric cancer with peritoneal metastasis is associated with a poor prognosis. Current treatments, including the first-line therapy of combination chemotherapy with nivolumab for advanced recurrent gastric cancer, have shown limited efficacy against peritoneal dissemination. In this study, we evaluated neoantigen (neoAg)-mRNA lipid nanoparticle (LNP) as a potential agent in combination with anti-PD-1 therapy, focusing on its effects on neoAg-specific CD8<sup>+</sup> T cell responses and antitumor efficacy in a murine gastric cancer model.</p><p><strong>Methods: </strong>The mRNA, comprising a tandem minigene encoding three neoAgs identified from the murine gastric cancer YTN16 cell line, was synthesized by in vitro transcription and encapsulated within LNPs. NeoAg-specific CD8<sup>+</sup> T cells in the spleens and tumors were assessed by flow cytometry. The antitumor efficacy of the neoAg-mRNA-LNP vaccine, alone or in combination with anti-PD-1 antibody, was evaluated in both subcutaneous and peritoneal metastasis models of YTN16.</p><p><strong>Results: </strong>The neoAg-mRNA-LNP vaccine induced significantly higher frequencies of neoAg-specific CD8<sup>+</sup> T cells than the neoAg-dendritic cell vaccine, confirming its enhanced immunogenicity. NeoAg-mRNA-LNP vaccination led to robust tumor regression, achieving complete eradication in all treated mice, especially when combined with anti-PD-1 therapy. This effect was associated with an increase in neoAg-specific progenitor-exhausted and intermediate-exhausted CD8<sup>+</sup> T cells. In a peritoneal metastasis model, neoAg-mRNA-LNP monotherapy prevented peritoneal dissemination when administered prophylactically, and combination therapy with anti-PD-1 effectively suppressed tumor growth in a therapeutic setting.</p><p><strong>Conclusions: </strong>NeoAg-mRNA-LNP vaccines elicit potent neoAg-specific CD8<sup>+</sup> T cell responses and show enhanced antitumor efficacy with anti-PD-1 therapy in gastric cancer with peritoneal metastasis.</p>","PeriodicalId":12684,"journal":{"name":"Gastric Cancer","volume":" ","pages":"825-836"},"PeriodicalIF":5.1000,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12378472/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Gastric Cancer","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s10120-025-01640-8","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/7/31 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"GASTROENTEROLOGY & HEPATOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Gastric cancer with peritoneal metastasis is associated with a poor prognosis. Current treatments, including the first-line therapy of combination chemotherapy with nivolumab for advanced recurrent gastric cancer, have shown limited efficacy against peritoneal dissemination. In this study, we evaluated neoantigen (neoAg)-mRNA lipid nanoparticle (LNP) as a potential agent in combination with anti-PD-1 therapy, focusing on its effects on neoAg-specific CD8+ T cell responses and antitumor efficacy in a murine gastric cancer model.
Methods: The mRNA, comprising a tandem minigene encoding three neoAgs identified from the murine gastric cancer YTN16 cell line, was synthesized by in vitro transcription and encapsulated within LNPs. NeoAg-specific CD8+ T cells in the spleens and tumors were assessed by flow cytometry. The antitumor efficacy of the neoAg-mRNA-LNP vaccine, alone or in combination with anti-PD-1 antibody, was evaluated in both subcutaneous and peritoneal metastasis models of YTN16.
Results: The neoAg-mRNA-LNP vaccine induced significantly higher frequencies of neoAg-specific CD8+ T cells than the neoAg-dendritic cell vaccine, confirming its enhanced immunogenicity. NeoAg-mRNA-LNP vaccination led to robust tumor regression, achieving complete eradication in all treated mice, especially when combined with anti-PD-1 therapy. This effect was associated with an increase in neoAg-specific progenitor-exhausted and intermediate-exhausted CD8+ T cells. In a peritoneal metastasis model, neoAg-mRNA-LNP monotherapy prevented peritoneal dissemination when administered prophylactically, and combination therapy with anti-PD-1 effectively suppressed tumor growth in a therapeutic setting.
Conclusions: NeoAg-mRNA-LNP vaccines elicit potent neoAg-specific CD8+ T cell responses and show enhanced antitumor efficacy with anti-PD-1 therapy in gastric cancer with peritoneal metastasis.
期刊介绍：
Gastric Cancer is an esteemed global forum that focuses on various aspects of gastric cancer research, treatment, and biology worldwide.
The journal promotes a diverse range of content, including original articles, case reports, short communications, and technical notes. It also welcomes Letters to the Editor discussing published articles or sharing viewpoints on gastric cancer topics.
Review articles are predominantly sought after by the Editor, ensuring comprehensive coverage of the field.
With a dedicated and knowledgeable editorial team, the journal is committed to providing exceptional support and ensuring high levels of author satisfaction. In fact, over 90% of published authors have expressed their intent to publish again in our esteemed journal.
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