胰腺导管腺癌（PDAC）患者的预后仍然非常差。有人认为，腺苷途径通过产生细胞外腺苷（eAdo）有助于PDAC逃避免疫系统，从而对免疫肿瘤学治疗（IOT）表现出耐药性。我们使用基因工程异种移植的PDAC小鼠模型、具有不同免疫浸润和IOT应答的同基因小鼠模型、以及KPC小鼠的自生原位肿瘤，研究了腺苷途径对PDAC肿瘤微环境（TME）的影响。我们使用流式细胞术和成像质谱细胞术（IMC）来表征肿瘤浸润免疫细胞的亚群频率和空间分布。我们使用质谱成像（MSI）来可视化PDAC肿瘤中腺苷的分区情况。我们使用RNA测序来评估腺苷途径对免疫环境的塑造的影响，并将我们的结果与已发表的人类PDAC数据集进行关联。我们证明在小鼠模型中，肿瘤浸润免疫细胞（尤其是髓系细胞群）高表达腺苷途径组分。MSI显示肿瘤细胞外腺苷分布在肿瘤中具有异质性，高浓度分布在周围坏死、缺氧区域，并与富含髓系细胞浸润相关。促肿瘤的M2巨噬细胞高表达Adora2a受体，特别是在IOT耐药模型中表现出。使用anti-CD73抗体和Adora2a抑制剂的联合治疗抑制了eAdo（Adoi）的形成和作用，减缓了肿瘤生长并减少了转移负担。此外，阻断腺苷途径提高了细胞毒性药物或免疫治疗的疗效。Adoi改变了TME，减少了M2巨噬细胞和调节性T细胞的浸润。RNA测序分析表明，与免疫调控、缺氧和肿瘤基质相关的基因在Adoi后下调，从而与PDAC患者的不良预后相关联。eAdo的形成促进了PDAC的免疫抑制TME发展，导致其对常规和新型治疗的耐药性。因此，抑制腺苷途径可能是调节PDAC免疫环境并提高患者治疗反应的策略。©作者（或其雇主）2023。在CC BY许可下允许再使用。由BMJ出版。

The prognosis for patients with pancreatic ductal adenocarcinoma (PDAC) remains extremely poor. It has been suggested that the adenosine pathway contributes to the ability of PDAC to evade the immune system and hence, its resistance to immuno-oncology therapies (IOT), by generating extracellular adenosine (eAdo).Using genetically engineered allograft models of PDAC in syngeneic mice with defined and different immune infiltration and response to IOT and autochthonous tumors in KPC mice we investigated the impact of the adenosine pathway on the PDAC tumor microenvironment (TME). Flow cytometry and imaging mass cytometry (IMC) were used to characterize the subpopulation frequency and spatial distribution of tumor-infiltrating immune cells. Mass spectrometry imaging (MSI) was used to visualize adenosine compartmentalization in the PDAC tumors. RNA sequencing was used to evaluate the influence of the adenosine pathway on the shaping of the immune milieu and correlate our findings to published data sets in human PDAC.We demonstrated high expression of adenosine pathway components in tumor-infiltrating immune cells (particularly myeloid populations) in the murine models. MSI demonstrated that extracellular adenosine distribution is heterogeneous in tumors, with high concentrations in peri-necrotic, hypoxic regions, associated with rich myeloid infiltration, demonstrated using IMC. Protumorigenic M2 macrophages express high levels of the Adora2a receptor; particularly in the IOT resistant model. Blocking the in vivo formation and function of eAdo (Adoi), using a combination of anti-CD73 antibody and an Adora2a inhibitor slowed tumor growth and reduced metastatic burden. Additionally, blocking the adenosine pathway improved the efficacy of combinations of cytotoxic agents or immunotherapy. Adoi remodeled the TME, by reducing the infiltration of M2 macrophages and regulatory T cells. RNA sequencing analysis showed that genes related to immune modulation, hypoxia and tumor stroma were downregulated following Adoi and a specific adenosine signature derived from this is associated with a poorer prognosis in patients with PDAC.The formation of eAdo promotes the development of the immunosuppressive TME in PDAC, contributing to its resistance to conventional and novel therapies. Therefore, inhibition of the adenosine pathway may represent a strategy to modulate the PDAC immune milieu and improve therapy response in patients with PDAC.© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.