Ludwig Center for Cancer Research; University of Lausanne; Lausanne, Switzerland.
Oncoimmunology. 2012 Jul 1;1(4):467-530. doi: 10.4161/onci.19856.
The relatively low frequencies of tumor Ag-specific T-cells in PBMC and metastases from cancer patients have long precluded the analysis of their direct ex vivo cytolytic capacity. Using a new composite technique that works well with low cell numbers, we aimed at determining the functional competence of melanoma-specific CD8(+) T-cells. A multiparameter flow cytometry based technique was applied to assess the cytolytic function, degranulation and IFNγ production by tumor Ag-specific CD8(+) T-cells from PBMC and tumor-infiltrated lymph nodes (TILN) of melanoma patients. We found strong cytotoxicity by T-cells not only when they were isolated from PBMC but also from TILN. Cytotoxicity was observed against peptide-pulsed target cells and melanoma cells presenting the naturally processed endogenous antigen. However, unlike their PBMC-derived counterparts, T-cells from TILN produced only minimal amounts of IFNγ, while exhibiting similar levels of degranulation, revealing a critical functional dichotomy in metastatic lesions. Our finding of partial functional impairment fits well with the current knowledge that T-cells from cancer metastases are so-called exhausted, a state of T-cell hyporesponsiveness also found in chronic viral infections. The identification of responsible mechanisms in the tumor microenvironment is important for improving cancer therapies.
在 PBMC 和癌症转移部位中，肿瘤 Ag 特异性 T 细胞的相对低频长期以来排除了对其直接离体细胞毒性能力的分析。使用一种新的复合技术，该技术在细胞数量较少的情况下效果很好，我们旨在确定黑色素瘤特异性 CD8(+) T 细胞的功能能力。应用一种基于多参数流式细胞术的技术来评估来自黑色素瘤患者 PBMC 和肿瘤浸润淋巴结 (TILN) 的肿瘤 Ag 特异性 CD8(+) T 细胞的细胞毒性、脱颗粒和 IFNγ 产生。我们发现 T 细胞不仅在从 PBMC 分离时而且在从 TILN 分离时具有很强的细胞毒性。当它们针对肽脉冲靶细胞和呈现天然加工的内源性抗原的黑色素瘤细胞时观察到细胞毒性。然而，与 PBMC 衍生的对应物不同，来自 TILN 的 T 细胞仅产生少量 IFNγ，同时表现出相似水平的脱颗粒，揭示了转移性病变中关键的功能二分法。我们发现的部分功能障碍与当前的知识相符，即来自癌症转移的 T 细胞是所谓的耗竭的，这种 T 细胞低反应性状态也存在于慢性病毒感染中。在肿瘤微环境中确定负责的机制对于改善癌症治疗很重要。
