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: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.
Project description:CD39+CD8+ T cells are known as tumour antigen-specific cells among CD8+ tumour-infiltrating lymphocytes (TILs). However, CD39+CD8+ T cells also reportedly exhibit immunosuppressive activity in hypoxic tumour models. Here we investigated CD39+CD8+ TILs with regards to their molecular phenotypes, developmental mechanisms, functions, and prognostic significance in clear cell renal cell carcinoma (ccRCC), a VHL mutation-associated hypoxic tumour. Single-cell RNA and TCR analyses confirmed that CD39+CD8+ cells are a terminally exhausted subset of tumour-specific CD8+ TILs. CD39+CD8+ T-cell development was highly correlated with cAMP signals, and was directly induced by cAMP and TCR signallings. Analysis of an RCC cohort revealed a markedly elevated proportion of CD39+ cells among CD8+ TILs in ccRCC, compared to non-ccRCC. Moreover, the proportion of CD39+CD8+ TILs was associated with high tumour mutational burden and hypoxic features. Ex vivo functional assays revealed that CD39+CD8+ TILs exerted immunosuppressive activity on neighbouring CD8+ T cells via ectonucleotidase activity- and adenosine-dependent mechanisms. CD39+CD8+ TIL enrichment predicted poor prognosis of ccRCC patients, yet also predicted favourable treatment responses to anti-PD-1 therapy. This paradoxical prognostic significance in ccRCC is explained by the dual properties of CD39+CD8+ TILs: tumour antigen specificity and immunosuppressive activity.
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.