简介：以往的研究已经证实免疫肿瘤微环境在恶性胸膜间皮瘤(MPM)中的预后作用。肿瘤浸润巨噬细胞是形成MPM肿瘤微环境中的白细胞的主要成分。巨噬细胞可分为两种主要表型：M1型巨噬细胞，具有抗肿瘤发生功能，M2型巨噬细胞具有促肿瘤发展的促生功能。巨噬细胞表型影响MPM的生物学行为，并可能提供潜在的治疗靶点。因此，我们目标在空间上描绘MPM肿瘤组织中巨噬细胞表达的五种标志物的表达，并评估其与患者存活关系。

        Introduction:Previous studies have demonstrated the prognostic role of the immunological tumor microenvironment in malignant pleural mesothelioma (MPM). Tumor-infiltrating macrophages form the major component of the leucocytes in MPM tumor microenvironment. Macrophages can be divided into two main phenotypes: type M1 macrophages have an anti-tumorigenic function and type M2 macrophages a pro-tumorigenic function promoting tumor development. The macrophage phenotypes affect the biological behavior of MPM and may provide potential therapeutic targets. Thus, we aimed to spatially profile the expression of five markers expressed by macrophages in MPM tumor tissue and assess their association with patient survival.

        方法：该研究队列由组织微阵列组成，包括来自76名芬兰MPM患者(71名上皮样和5名双相)的样本，其中包括18名存活至少60个月的患者。分析了巨噬细胞表达的标志物的位置特异性组织表达(CD68[Dako;M0876]，CMAF[Abcam;ab199424]，pSTAT1[Cell Signaling Technology;8826]，HLA-DRA1[Abcam;ab20181]和CD163[Abcam;ab188571])使用多重荧光免疫组织化学和基于数字像素的图像分析。测量单个标志物表达和标志物组合作为与总组织，基质或肿瘤面积成比例的面积。单变量Cox回归用于评估巨噬细胞表达与死亡时间(全因死亡率)之间的关联。

        Methods:The study cohort consisted of tissue microarrays including samples from 76 Finnish MPM patients (71 epithelioid and 5 biphasic), including 18 patients who survived at least 60 months. We analyzed location-specific tissue expression of markers expressed by macrophages (CD68 [Dako; M0876], CMAF [Abcam; ab199424], pSTAT1 [Cell Signaling Technology; 8826], HLA-DRA1 [Abcam; ab20181] and CD163 [Abcam; ab188571]) using multiplexed fluorescence immunohistochemistry and digital pixel-based image analysis. Single marker expressions and marker combinations were measured as proportional areas to total tissue, stromal, or tumor area. Univariate Cox regression was used to assess the association between macrophage expression and time to death (all-cause mortality).

        结果：在单变量Cox回归分析中，M2型促肿瘤发生巨噬细胞(CD163+CMAF+HLA-DRA1-)与较短存活时间相关(HR=9.54，p=0.03)，而M1型抗肿瘤发生巨噬细胞(CD68+pSTAT1+HLA-DRA1+)与较长存活时间相关(HR=0.87，p=0.03)。此外，表达pSTAT1的免疫原性肿瘤细胞(CK5+pSTAT1+CD68-CD163-HLA-DRA1-)的存在与更长的存活时间相关(HR=0.97，p<0.01)。

        Results:In univariate Cox regression analysis, type M2 pro-tumorigenic macrophages (CD163+CMAF+HLA-DRA1-) were associated with shorter survival time (HR=9.54, p=0.03), whereas type M1 anti-tumorigenic macrophages (CD68+pSTAT1+HLA-DRA1+) were associated with longer survival time (HR=0.87, p=0.03). Furthermore, the presence of pSTAT1 expressing immunogenic tumor cells (CK5+pSTAT1+CD68-CD163-HLA-DRA1-) was associated with longer survival time (HR=0.97, p<0.01).

        结论：M1型巨噬细胞和表达pSTAT1的肿瘤细胞的表达与较长的存活率相关，M2型巨噬细胞的表达与较短的存活率相关。这些可能提供新的免疫治疗靶点。

        Conclusion:The expression of type M1 macrophages and pSTAT1 expressing tumor cells were associated with longer survival and the expression of type M2 macrophages was associated with shorter survival. These may provide new immunotherapeutic targets.