Project description:We utilized cell surface expression of CD39 to demonstrate that this marker enriches for CD8+ T cells with features of exhaustion, proliferation and tumor reaxtivity.
Project description:We utilized cell surface expression of CD39 to demonstrate that this marker enriches for CD8+ T cells with features of exhaustion, proliferation and tumor reaxtivity.
Project description:We utilized cell surface expression of CD39 to demonstrate that this marker enriches for CD8+ T cells with features of exhaustion, proliferation and tumor reaxtivity.
Project description:Exhausted T cells express multiple co-inhibitory molecules that impair their function and limit immunity to chronic viral infection. Defining novel markers of exhaustion is important both for identifying and potentially reversing T cell exhaustion. Herein, we show that the ectonucleotidse CD39 is a marker of exhausted CD8+ T cells. CD8+ T cells specific for HCV or HIV express high levels of CD39, but those specific for EBV and CMV do not. CD39 expressed by CD8+ T cells in chronic infection is enzymatically active, co-expressed with PD-1, marks cells with a transcriptional signature of T cell exhaustion and correlates with viral load in HIV and HCV. In the mouse model of chronic Lymphocytic Choriomeningitis Virus infection, virus-specific CD8+ T cells contain a population of CD39high CD8+ T cells that is absent in functional memory cells elicited by acute infection. This CD39high CD8+ T cell population is enriched for cells with the phenotypic and functional profile of terminal exhaustion. These findings provide a new marker of T cell exhaustion, and implicate the purinergic pathway in the regulation of T cell exhaustion. CD8+ T cells from subjects with HCV infection were sorted and pelleted and re-suspended in TRIzol (Invitrogen). RNA extraction was performed using the RNAdvance Tissue Isolation kit (Agencourt). Concentrations of total RNA were determined with a Nanodrop spectrophotometer or Ribogreen RNA quantification kits (Molecular Probes/Invitrogen). RNA purity was determined by Bioanalyzer 2100 traces (Agilent Technologies). Total RNA was amplified with the WT-Ovation Pico RNA Amplification system (NuGEN) according to the manufacturer's instructions. After fragmentation and biotinylation, cDNA was hybridized to HG-U133A 2.0 microarrays (Affymetrix).
Project description:Exhausted T cells express multiple co-inhibitory molecules that impair their function and limit immunity to chronic viral infection. Defining novel markers of exhaustion is important both for identifying and potentially reversing T cell exhaustion. Herein, we show that the ectonucleotidse CD39 is a marker of exhausted CD8+ T cells. CD8+ T cells specific for HCV or HIV express high levels of CD39, but those specific for EBV and CMV do not. CD39 expressed by CD8+ T cells in chronic infection is enzymatically active, co-expressed with PD-1, marks cells with a transcriptional signature of T cell exhaustion and correlates with viral load in HIV and HCV. In the mouse model of chronic Lymphocytic Choriomeningitis Virus infection, virus-specific CD8+ T cells contain a population of CD39high CD8+ T cells that is absent in functional memory cells elicited by acute infection. This CD39high CD8+ T cell population is enriched for cells with the phenotypic and functional profile of terminal exhaustion. These findings provide a new marker of T cell exhaustion, and implicate the purinergic pathway in the regulation of T cell exhaustion.
Project description:Human tumors are infiltrated by various immune cells, including CD8 T cells. CD8 T cells express unique receptors that can recognize peptides at the host’s cells, including tumor cells. After probing the antigen specificity of ex-vivo tumor-infiltrating CD8 T cells from human tumors, we hypothesized that expression of CD39 was correlated with tumor-specificity. The present experiment aims at better characterizing ex-vivo CD39+ vs CD39- CD8 T cells.
Project description:Tumor-reactive CD8+ tumor infiltrating lymphocytes (TILs) represent a subtype of T cells that could 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. In this study, we segregated tumor-reactive and bystander CD8+ TILs, as well as naïve and effector memory CD8+ T cell subtypes as controls from colorectal cancer (CRC) patients, to compare their transcriptome and methylome characteristics. Transcriptome profiling confirmed previous conclusion that tumor-reactive TILs have an exhausted tissue-resident memory signature. Whole-genome methylation profiling identified a distinct methylome pattern of tumor-reactive CD8+ T cells, with tumor-reactive markers (CD39 and CD103) being specifically demethylated. In addition, dynamic changes were observed during the transition of naïve T cells into tumor-reactive CD8+ T cells. Transcription factor (TF) binding motif enrichment analysis identified several immune-related TFs, including three exhaustion-related genes (NR4A1, BATF and EGR2) and VDR, that potentially play important regulatory role in tumor-reactive CD8+ T cells. 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.