Clinical Significance of PD-L1(+) Exosomes in Plasma of Head and Neck Cancer Patients.
Clinical Significance of PD-L1(+) Exosomes in Plasma of Head and Neck Cancer Patients.
复制标题
头颈癌患者血浆中 PD-L1(+) 外泌体的临床意义。
DOI：
10.1158/1078-0432.ccr-17-2664
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发表时间：
2018-02-15
期刊：
影响因子：
--
通讯作者：
Whiteside TL
中科院分区：
文献类型：
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作者：
Theodoraki MN;Yerneni SS;Hoffmann TK;Gooding WE;Whiteside TL
头颈部鳞状细胞癌（HNSCC）的微环境是高度免疫抑制的。表达升高水平的PD-L1的HNSCC具有特别差的结果。携带PD-L1并抑制T细胞功能的外泌体已从HNSCC患者的血浆中分离出来。评估PD-L1+外泌体对免疫抑制和疾病活动的潜在贡献。通过尺寸排阻色谱法从40名HNSCC患者的血浆中分离的外泌体使用抗CD 63 Ab捕获在珠上，针对PD-1和PD-L1染色并通过流式细胞术分析。PD-L1+和PD-1+外泌体/珠复合物的百分比和平均荧光强度（MFI）与患者的临床病理数据相关。将PD-L1高或PD-L1低外泌体与活化的CD 69+人CD 8 + T细胞± PD-1抑制剂一起孵育。测量T细胞上CD 69表达水平的变化。通过ELISA检测患者血浆中的可溶性PD-L1（sPD-L1）。外泌体携带的PD-L1水平与患者的疾病活动性、UICC分期和淋巴结状态相关（p= 0.0008-0.013）。相比之下，血浆sPD-L1水平或外泌体PD-1水平与任何临床病理学参数均不相关。与PD-L1高共孵育可抑制CD 69表达水平（p<0.03），但PD-L1低外泌体不抑制。阻断PD-L1+外泌体向PD-1+ T细胞的信号传导减弱了免疫抑制。外泌体上的PD-L1水平，而不是sPD-L1水平，与HNSCC患者的疾病进展相关。循环PD-L1+外泌体成为HNSCC患者疾病和免疫活性的有用指标。
The microenvironment of head and neck squamous cell carcinomas (HNSCCs) is highly immunosuppressive. HNSCCs expressing elevated levels of PD-L1 have especially poor outcome. Exosomes that carry PD-L1 and suppress T-cell functions have been isolated from plasma of patients with HNSCC. The potential contributions of PD-L1+ exosomes to immune suppression and disease activity are evaluated. Exosomes isolated from plasma of 40 HNSCC patients by size exclusion chromatography were captured on beads using anti-CD63 Abs, stained for PD-1 and PD-L1 and analyzed by flow cytometry. The percentages and mean fluorescence intensities (MFIs) of PD-L1+ and PD-1+ exosome/bead complexes were correlated with the patients’ clinicopathological data. PD-L1high or PD-L1low exosomes were incubated with activated CD69+ human CD8+ T-cells ± PD-1 inhibitor. Changes in CD69 expression levels on T cells were measured. Patients’ plasma was tested for soluble PD-L1 (sPD-L1) by ELISA. Levels of PD-L1 carried by exosomes correlated with patients’ disease activity, the UICC stage and the lymph node status (p= 0.0008–0.013). In contrast, plasma levels of sPD-L1 or exosome PD-1 levels did not correlate with any clinicopathological parameters. CD69 expression levels were inhibited (p<0.03) by co-incubation with PD-L1high but not by PD-L1low exosomes. Blocking of PD-L1+ exosome signaling to PD-1+ T cells attenuated immune suppression. PD-L1 levels on exosomes, but not levels of sPD-L1, associated correlate with disease progression in HNSCC patients. Circulating PD-L1+ exosomes emerge as useful metrics of disease and immune activity in HNSCC patients.