Activation of STING-Dependent Innate Immune Signaling By S-Phase-Specific DNA Damage in Breast Cancer.
Activation of STING-Dependent Innate Immune Signaling By S-Phase-Specific DNA Damage in Breast Cancer.
复制标题
DOI：
10.1093/jnci/djw199
复制
发表时间：
2017-01
期刊：
影响因子：
--
通讯作者：
Kennedy RD
中科院分区：
文献类型：
--
作者：
Parkes EE;Walker SM;Taggart LE;McCabe N;Knight LA;Wilkinson R;McCloskey KD;Buckley NE;Savage KI;Salto-Tellez M;McQuaid S;Harte MT;Mullan PB;Harkin DP;Kennedy RD
背景：之前我们在乳腺癌中发现了一种 DNA 损伤反应缺陷 (DDRD) 分子亚型。鉴定该亚型的 44 基因检测被验证可以预测 DNA 损伤性化疗的益处。该亚型是由干扰素信号传导定义的。在这项研究中，我们探讨了这种免疫反应的机制及其可能的临床意义。 方法：我们使用免疫组织化学 (IHC) 来表征 184 个乳腺癌样本中的免疫浸润，其中 65 个属于 DDRD 亚型。使用代表DDRD阳性和阴性的同基因细胞系来研究趋化因子释放对外周血单核细胞（PBMC）迁移的影响以及免疫信号激活的机制。最后，我们研究了 IHC 检测到的 DDRD 亚型与免疫检查点蛋白 PD-L1 表达之间的关联。所有统计检验都是双面的。 结果：我们发现 DDRD 乳腺肿瘤与 CD4+ 和 CD8+ 淋巴细胞浸润相关（Fisher 精确检验 P < .001），并且 DDRD 细胞表达趋化因子 CXCL10 和 CCL5 是 DNA 损伤反应熟练细胞的 3.5 至 11.9 倍（P < .01）。与来自 DNA 损伤反应熟练细胞的培养基相比，来自 DDRD 细胞的条件培养基在统计学上显着地吸引了 PBMC (P < .05)，并且这取决于 CXCL10 和 CCL5。 DDRD 细胞表现出胞质 DNA 增加和病毒反应 cGAS/STING/TBK1/IRF3 途径的组成型激活。重要的是，该途径以细胞周期特异性方式被激活。最后，我们证明 S 期 DNA 损伤以 STING 依赖性方式激活 PD-L1 的表达。 结论：我们提出了一种独立于新抗原产生的 DDRD 肿瘤免疫浸润的新机制。该通路的激活和相关的 PD-L1 表达可以解释在 DDRD 肿瘤中观察到的 T 细胞介导的细胞毒性的矛盾缺乏。我们为探索 DDRD 在患者分层中进行基于免疫检查点的治疗提供了理论依据。
Background: Previously we identified a DNA damage response–deficient (DDRD) molecular subtype within breast cancer. A 44-gene assay identifying this subtype was validated as predicting benefit from DNA-damaging chemotherapy. This subtype was defined by interferon signaling. In this study, we address the mechanism of this immune response and its possible clinical significance. Methods: We used immunohistochemistry (IHC) to characterize immune infiltration in 184 breast cancer samples, of which 65 were within the DDRD subtype. Isogenic cell lines, which represent DDRD-positive and -negative, were used to study the effects of chemokine release on peripheral blood mononuclear cell (PBMC) migration and the mechanism of immune signaling activation. Finally, we studied the association between the DDRD subtype and expression of the immune-checkpoint protein PD-L1 as detected by IHC. All statistical tests were two-sided. Results: We found that DDRD breast tumors were associated with CD4+ and CD8+ lymphocytic infiltration (Fisher’s exact test P < .001) and that DDRD cells expressed the chemokines CXCL10 and CCL5 3.5- to 11.9-fold more than DNA damage response–proficient cells (P < .01). Conditioned medium from DDRD cells statistically significantly attracted PBMCs when compared with medium from DNA damage response–proficient cells (P < .05), and this was dependent on CXCL10 and CCL5. DDRD cells demonstrated increased cytosolic DNA and constitutive activation of the viral response cGAS/STING/TBK1/IRF3 pathway. Importantly, this pathway was activated in a cell cycle–specific manner. Finally, we demonstrated that S-phase DNA damage activated expression of PD-L1 in a STING-dependent manner. Conclusions: We propose a novel mechanism of immune infiltration in DDRD tumors, independent of neoantigen production. Activation of this pathway and associated PD-L1 expression may explain the paradoxical lack of T-cell-mediated cytotoxicity observed in DDRD tumors. We provide a rationale for exploration of DDRD in the stratification of patients for immune checkpoint–based therapies.