1. Distinct epigenetic features of tumor-reactive CD8+ T cells in colorectal cancer patients revealed by genome-wide DNA methylation analysis
- Author
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Rui Yang, Sijin Cheng, Nan Luo, Ranran Gao, Kezhuo Yu, Boxi Kang, Li Wang, Qiming Zhang, Qiao Fang, Lei Zhang, Chen Li, Aibin He, Xueda Hu, Jirun Peng, Xianwen Ren, and Zemin Zhang
- Subjects
Colorectal cancer ,Tumor-reactive T cells ,Bystanders ,Transcriptome ,Methylome ,Transcription factor ,Biology (General) ,QH301-705.5 ,Genetics ,QH426-470 - Abstract
Abstract Background Tumor-reactive CD8+ tumor-infiltrating lymphocytes (TILs) represent a subtype of T cells that can recognize and destroy tumor specifically. Understanding the regulatory mechanism of tumor-reactive CD8+ T cells has important therapeutic implications. Yet the DNA methylation status of this T cell subtype has not been elucidated. Results In this study, we segregate tumor-reactive and bystander CD8+ TILs, as well as naïve and effector memory CD8+ T cell subtypes as controls from colorectal cancer patients, to compare their transcriptome and methylome characteristics. Transcriptome profiling confirms previous conclusions that tumor-reactive TILs have an exhausted tissue-resident memory signature. Whole-genome methylation profiling identifies a distinct methylome pattern of tumor-reactive CD8+ T cells, with tumor-reactive markers CD39 and CD103 being specifically demethylated. In addition, dynamic changes are observed during the transition of naïve T cells into tumor-reactive CD8+ T cells. Transcription factor binding motif enrichment analysis identifies several immune-related transcription factors, including three exhaustion-related genes (NR4A1, BATF, and EGR2) and VDR, which potentially play an important regulatory role in tumor-reactive CD8+ T cells. Conclusion Our study supports the involvement of DNA methylation in shaping tumor-reactive and bystander CD8+ TILs, and provides a valuable resource for the development of novel DNA methylation markers and future therapeutics.
- Published
- 2019
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