除了在肿瘤细胞中发挥合成致死作用外，聚（ADP-核糖）聚合酶抑制剂（PARPis）还可以协调肿瘤免疫微环境（TIME），有助于抑制肿瘤生长。然而，目前尚不完全清楚 PARPis 是否以及如何触发肿瘤靶向免疫反应。为了解码 PARPis 重塑的免疫反应，我们对治疗前后的配对临床标本进行了 T 细胞受体 (TCR) 测序和免疫组织化学 (IHC) 分析。 niraparib 单药疗法来自一项前瞻性研究，以及 ID8 小鼠卵巢肿瘤。为了验证 PARPis 诱导免疫原性细胞死亡 (ICD)，我们分别对同源重组缺陷肿瘤细胞和患者来源的异种移植肿瘤组织进行免疫荧光/IHC 染色。为了证实 PARPis 引起肿瘤细胞焦亡，我们对细胞形态特征、gasdermin (GSDM) 蛋白的裂解以及通过基因下调/耗竭和选择性抑制激活 TNF-caspase 信号通路进行了全面评估。我们还使用同基因小鼠模型，将 CRISPR/Cas9 编辑的 Gsdme-/ - ID8 肿瘤细胞植入 C57BL/6 小鼠体内，评估了尼拉帕尼治疗后焦亡在肿瘤抑制和免疫激活中的关键作用。我们的研究结果表明，PARPis 增加了新抗原识别的 TCR 克隆和 TCR 克隆扩增，并诱导炎症 TIME，其特征是先天性和适应性免疫细胞的浸润增加。这种 PARPis 增强的免疫反应与 ICD 的诱导有关，特别是细胞焦亡，它具有独特的形态特征和 GSDMD/E 裂解。经验证，GSDMD/E 的裂解是由于 TNFR1 下游的 caspase 8 活性升高所致，而不是 FAS 和 TRAIL-R。抑制 PARP 后，NF-κB 信号通路被激活，导致 TNF-α 分泌增加，随后引发 TNFR1-caspase 8 级联反应。在同基因 ID8 小鼠模型中，通过消耗 Gsdme 来阻止细胞焦亡显着损害了 PARP 抑制的肿瘤抑制作用，并破坏了抗免疫反应。PARPis 通过 TNF-caspase 8-GSDMD/E 轴诱导一种称为细胞焦亡的特定类型的 ICD ，导致 TIME 发炎并增强肿瘤靶向免疫反应。这些发现加深了我们对 PARPis 活动的理解，并为 PARPis 与免疫治疗干预措施的协同作用指明了一条有前途的途径。NCT04507841.© 作者（或其雇主）2024。在 CC BY-NC 下允许重复使用。禁止商业再利用。请参阅权利和权限。英国医学杂志出版。

In addition to their established action of synthetic lethality in tumor cells, poly(ADP-ribose) polymerase inhibitors (PARPis) also orchestrate tumor immune microenvironment (TIME) that contributes to suppressing tumor growth. However, it remains not fully understood whether and how PARPis trigger tumor-targeting immune responses.To decode the immune responses reshaped by PARPis, we conducted T-cell receptor (TCR) sequencing and immunohistochemical (IHC) analyses of paired clinical specimens before and after niraparib monotherapy obtained from a prospective study, as well as ID8 mouse ovarian tumors. To validate the induction of immunogenic cell death (ICD) by PARPis, we performed immunofluorescence/IHC staining with homologous recombination deficiency tumor cells and patient-derived xenograft tumor tissues, respectively. To substantiate that PARPis elicited tumor cell pyroptosis, we undertook comprehensive assessments of the cellular morphological features, cleavage of gasdermin (GSDM) proteins, and activation of TNF-caspase signaling pathways through genetic downregulation/depletion and selective inhibition. We also evaluated the critical role of pyroptosis in tumor suppression and immune activation following niraparib treatment using a syngeneic mouse model with implanting CRISPR/Cas9 edited Gsdme-/ - ID8 tumor cells into C57BL/6 mice.Our findings revealed that PARPis augmented the proportion of neoantigen-recognized TCR clones and TCR clonal expansion, and induced an inflamed TIME characterized by increased infiltration of both innate and adaptive immune cells. This PARPis-strengthened immune response was associated with the induction of ICD, specifically identified as pyroptosis, which possessed distinctive morphological features and GSDMD/E cleavage. It was validated that the cleavage of GSDMD/E was due to elevated caspase 8 activity downstream of the TNFR1, rather than FAS and TRAIL-R. On PARP inhibition, the NF-κB signaling pathway was activated, leading to increased secretion of TNF-α and subsequent initiation of the TNFR1-caspase 8 cascade. Impeding pyroptosis through the depletion of Gsdme significantly compromised the tumor-suppressing effects of PARP inhibition and undermined the anti-immune response in the syngeneic ID8 mouse model.PARPis induce a specific type of ICD called pyroptosis via TNF-caspase 8-GSDMD/E axis, resulting in an inflamed TIME and augmentation of tumor-targeting immune responses. These findings deepen our understanding of PARPis activities and point toward a promising avenue for synergizing PARPis with immunotherapeutic interventions.NCT04507841.© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.