文章：

抗原暗物质：胰腺癌中肿瘤相关与肿瘤特异性抗原未探索的翻译后修饰

Antigenic Dark Matter: Unexplored Post-Translational Modifications of Tumor-Associated and Tumor-Specific Antigens in Pancreatic Cancer

原文发布日期：30 October 2025

DOI: 10.3390/cancers17213506

类型: Article

开放获取: 是

英文摘要：

Background:Pancreatic ductal adenocarcinoma (PDAC) exhibits marked resistance to immunotherapy. Beyond its characteristically low tumor mutational burden, post-translational modifications (PTMs) remodel the immunopeptidome and promote immune escape through reversible, enzyme-driven programs.Subject Matter:We synthesize evidence that aberrant glycosylation, O-GlcNAcylation, phosphorylation, and citrullination constitute core determinants of antigen visibility operating within spatially discrete tumor niches and a desmoplastic stroma. In hypoxic regions, HIF-linked hexosamine metabolism and OGT activity stabilize immune checkpoints and attenuate antigen processing; at tumor margins, sialylated mucins engage inhibitory Siglec receptors on innate and adaptive lymphocytes; within the stroma, PAD4-dependent NET formation enforces T cell exclusion. We also delineate technical barriers to discovering PTM antigens labile chemistry, low stoichiometry, and method-embedded biases and outline practical solutions: ETD/EThcD/AI-ETD fragmentation, PTM-aware database searching and machine-learning models, and autologous validation in patient-derived organoid–T cell co-cultures. Finally, we highlight therapeutic strategies that either immunize against PTM neoepitopes or inhibit PTM machinery (e.g., PAD4, OGT, ST6GAL1), with stromal remodeling as an enabling adjunct.Conclusions:PTM biology, spatial omics, and patient sample models can uncover targetable niches and speed up PDAC vaccination, TCR, and enzyme-directed treatment development.

摘要翻译： 

背景：胰腺导管腺癌（PDAC）对免疫疗法表现出显著的耐药性。除了其典型的低肿瘤突变负荷外，翻译后修饰（PTMs）通过可逆的酶驱动程序重塑免疫肽组并促进免疫逃逸。 主题内容：我们综合证据表明，异常糖基化、O-GlcNAc修饰、磷酸化和瓜氨酸化构成了在空间上离散的肿瘤微环境和促纤维增生基质中影响抗原可见性的核心决定因素。在缺氧区域，HIF相关的己糖胺代谢和OGT活性稳定免疫检查点并减弱抗原加工；在肿瘤边缘，唾液酸化黏蛋白与先天性和适应性淋巴细胞上的抑制性Siglec受体结合；在基质内，PAD4依赖的NET形成强制排除T细胞。我们还阐述了发现PTM抗原的技术障碍——不稳定的化学性质、低化学计量比以及方法固有的偏差，并概述了实用解决方案：ETD/EThcD/AI-ETD碎裂技术、PTM感知的数据库搜索和机器学习模型，以及在患者来源类器官-T细胞共培养体系中的自体验证。最后，我们重点介绍了针对PTM新表位进行免疫接种或抑制PTM相关酶（如PAD4、OGT、ST6GAL1）的治疗策略，并将基质重塑作为辅助手段。 结论：PTM生物学、空间组学及患者样本模型能够揭示可靶向的肿瘤微环境，并加速PDAC疫苗、TCR疗法及酶导向治疗的开发进程。

原文链接：

Antigenic Dark Matter: Unexplored Post-Translational Modifications of Tumor-Associated and Tumor-Specific Antigens in Pancreatic Cancer