Department of Research, Lausanne University Hospital, Lausanne, Switzerland.
J Immunother. 2012 Jul;35(6):488-501. doi: 10.1097/CJI.0b013e31826183a7.
Phenotypic and functional cell properties are usually analyzed at the level of defined cell populations but not single cells. Yet, large differences between individual cells may have important functional consequences. It is likely that T-cell-mediated immunity depends on the polyfunctionality of individual T cells, rather than the sum of functions of responding T-cell subpopulations. We performed highly sensitive single-cell gene expression profiling, allowing the direct ex vivo characterization of individual virus-specific and tumor-specific T cells from healthy donors and melanoma patients. We have previously shown that vaccination with the natural tumor peptide Melan-A-induced T cells with superior effector functions as compared with vaccination with the analog peptide optimized for enhanced HLA-A*0201 binding. Here we found that natural peptide vaccination induced tumor-reactive CD8 T cells with frequent coexpression of both memory/homing-associated genes (CD27, IL7R, EOMES, CXCR3, and CCR5) and effector-related genes (IFNG, KLRD1, PRF1, and GZMB), comparable with protective Epstein-Barr virus-specific and cytomegalovirus-specific T cells. In contrast, memory/homing-associated and effector-associated genes were less frequently coexpressed after vaccination with the analog peptide. Remarkably, these findings reveal a previously unknown level of gene expression diversity among vaccine-specific and virus-specific T cells with the simultaneous coexpression of multiple memory/homing-related and effector-related genes by the same cell. Such broad functional gene expression signatures within antigen-specific T cells may be critical for mounting efficient responses to pathogens or tumors. In summary, direct ex vivo high-resolution molecular characterization of individual T cells provides key insights into the processes shaping the functional properties of tumor-specific and virus-specific T cells.
表型和功能细胞特性通常在定义的细胞群体水平上进行分析，但不是在单个细胞水平上。然而，个体细胞之间的巨大差异可能具有重要的功能后果。T 细胞介导的免疫很可能依赖于单个 T 细胞的多功能性，而不是应答 T 细胞亚群功能的总和。我们进行了高度敏感的单细胞基因表达谱分析，允许直接对来自健康供体和黑色素瘤患者的单个病毒特异性和肿瘤特异性 T 细胞进行体外特征描述。我们之前已经表明，与用优化用于增强 HLA-A*0201 结合的模拟肽进行疫苗接种相比，用天然肿瘤肽 Melan-A 进行疫苗接种可诱导具有优越效应功能的 T 细胞。在这里，我们发现天然肽疫苗接种可诱导肿瘤反应性 CD8 T 细胞频繁共表达记忆/归巢相关基因（CD27、IL7R、EOMES、CXCR3 和 CCR5）和效应相关基因（IFNG、KLRD1、PRF1 和 GZMB），与保护性 EBV 特异性和巨细胞病毒特异性 T 细胞相当。相比之下，用模拟肽进行疫苗接种后，记忆/归巢相关和效应相关基因的共表达频率较低。值得注意的是，这些发现揭示了疫苗特异性和病毒特异性 T 细胞之间以前未知的基因表达多样性水平，同一细胞同时共表达多个记忆/归巢相关和效应相关基因。抗原特异性 T 细胞中这种广泛的功能基因表达特征对于产生针对病原体或肿瘤的有效反应可能至关重要。总之，对单个 T 细胞进行直接的体外高分辨率分子特征分析为了解塑造肿瘤特异性和病毒特异性 T 细胞功能特性的过程提供了关键见解。
