Department of General Surgery, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China.
J Transl Med. 2018 Oct 25;16(1):294. doi: 10.1186/s12967-018-1673-6.
The prognosis of pancreatic ductal adenocarcinoma (PDAC) remains poor due to the difficulty of disease diagnosis and therapy. Immunotherapy has had robust performance against several malignancies, including PDAC. In this study, we aim to analyze the expression of CD8 and FoxP3 on T lymphocytes and TGF-β expression in tumor tissues, and then analyze the possible clinical significance of these finding in order to find a novel effective immunotherapy target in PDAC using a murine model.
A tissue microarray using patient PDAC samples was stained and analyzed for associations with clinicopathological characteristics. A preclinical murine model administrated with various immunotherapies were analyzed by growth inhibitor, flow cytometry, enzyme-linked immuno sorbent assay and immunohistochemistry.
The infiltrating FoxP3 regulatory T cells (Tregs) in tumor tissues were associated with survival, while CD8 tumor infiltrating lymphocytes (TILs) were not. Considering the drawbacks of these measure alone, the number of CD8 and FoxP3 T cells were combined to create a new estimated value-integrated immune ratio (IIR), which showed excellent validity in survival risk stratification. IIR was further verified as an independent prognostic factor according to multivariate analysis as well as TGF-β expression. Association between TGF-β expression and infiltrating Tregs was also verified. Then, in our preclinical murine model, CD25 and TGF-β combination blockade had a higher tumor growth inhibitor value. This combination therapy significantly depleted periphery and intra-tumor FoxP3 Tregs while increasing intra-tumor CD8 TILs levels compared to controls or anti-TGF-β monotherapy (p < 0.05). Anti-CD25 monotherapy alone also had the ability to deplete periphery and intra-tumor Tregs (p < 0.05). The excretion of intra-tumor IL-10, TGF-β was notably lower but higher IFN-γ excretion in this combination immunotherapy. Such combination immunotherapy was further confirmed to synergize with anti-PD-1 monotherapy to improve tumor growth inhibition and cure rates.
The combination of CD25, TGF-β and PD-1 blockade plays a potentially effective role in inhibiting tumor formation and progression. Our results also provide a strong rational strategy for use of IIR in future immunotherapy clinical trials.
由于疾病诊断和治疗的困难，胰腺导管腺癌（PDAC）的预后仍然很差。免疫疗法在包括 PDAC 在内的多种恶性肿瘤中表现出强大的疗效。在这项研究中，我们旨在分析 T 淋巴细胞上的 CD8 和 FoxP3 的表达以及肿瘤组织中 TGF-β 的表达，并分析这些发现的可能临床意义，以便在 PDAC 中找到一种新的有效的免疫治疗靶点，我们使用了一种鼠模型。
使用患者 PDAC 样本的组织微阵列进行染色并分析与临床病理特征的关联。通过生长抑制剂、流式细胞术、酶联免疫吸附试验和免疫组织化学分析，对接受各种免疫治疗的临床前鼠模型进行分析。
肿瘤组织中浸润的 FoxP3 调节性 T 细胞（Tregs）与生存相关，而 CD8 肿瘤浸润淋巴细胞（TILs）则不然。考虑到这些措施单独存在的缺陷，将 CD8 和 FoxP3 T 细胞的数量结合起来，创建了一个新的估计值综合免疫比（IIR），该比在生存风险分层中表现出优异的有效性。根据多变量分析和 TGF-β 表达，IIR 进一步被验证为独立的预后因素。还验证了 TGF-β 表达与浸润性 Tregs 之间的关联。然后，在我们的临床前鼠模型中，CD25 和 TGF-β 联合阻断具有更高的肿瘤生长抑制值。与对照组或抗 TGF-β 单药治疗相比，这种联合治疗显著减少了外周和肿瘤内 FoxP3 Tregs ，同时增加了肿瘤内 CD8 TIL 水平（p<0.05）。抗 CD25 单药治疗本身也有能力消耗外周和肿瘤内 Tregs（p<0.05）。这种联合免疫治疗还显著降低了肿瘤内 IL-10、TGF-β的排泄，但 IFN-γ 的排泄增加。这种联合免疫治疗进一步被证实与抗 PD-1 单药治疗协同作用，以提高肿瘤生长抑制率和治愈率。
CD25、TGF-β 和 PD-1 阻断的联合在抑制肿瘤形成和进展方面发挥了潜在的有效作用。我们的结果还为未来免疫治疗临床试验中使用 IIR 提供了强有力的合理策略。
