Project description:CD8 T cells normally differentiate from resting naïve T cells into function effector and then memory CD8 T cells following acute infections. During chronic viral infections, however, virus-specific CD8 T cells often become exhausted. We used microarrays to examine the gene expression differences between naive, effector, memory and exhausted virus-specific CD8 T cells following lymphocytic choriomeningitis virus infection. Experiment Overall Design: Three or four independent samples were sorted by flow cytometry for each cell type (naive, effector, memory and exhausted) virus-specific CD8 T cells. RNA was extracted and hybridized to Affymetrix microarrays.
Project description:CD8 T cells normally differentiate from resting naïve T cells into function effector and then memory CD8 T cells following acute infections. During chronic viral infections, however, virus-specific CD8 T cells often become exhausted. We used microarrays to examine the gene expression differences between naive, effector, memory and exhausted virus-specific CD8 T cells following lymphocytic choriomeningitis virus infection. Keywords: infection response
Project description:T cell dysfunction is an important feature of many chronic viral infections. In particular, it was shown that PD-1 regulates T cell dysfunction during chronic LCMV infection in mice and PD-1 high cells exhibit an intense exhausted gene signature. These findings were extended to human chronic infections such as HIV, HCV and HBV. However, it is not known if PD-1 high cells of healthy humans have the traits of exhausted cells. In this study, we provide a comprehensive description of phenotype, function and gene expression profiles of PD-1 high versus PD-1 low CD8 T cells in the peripheral blood of healthy human adults as following: 1) The percentage of naive and memory CD8 T cells varied widely in the peripheral blood cells of healthy humans and PD-1 was expressed by the memory CD8 T cells. 2) PD-1 high CD8 T cells in healthy humans did not significantly correlated with the PD-1 high exhausted gene signature of HIV specific human CD8 T cells or chronic LCMV specific CD8 T cells from mice. 3) PD-1 expression did not directly affect the ability of CD8 T cells to secrete cytokines in healthy adults. 4) PD-1 was expressed by the effector memory (TEM) compared to ‘terminally differentiated effector’ (TEMRA) CD8 T cells. 5) Finally, an interesting inverse relationship between CD45RA and PD-1 expression was observed. We used highly purified PD-1 high and PD-1 low from six healthy adult individuals and naive CD8 T cell populations from four of those individuals for gene expression studies
Project description:CD8+ T cells play a critical role in the immune response to viral pathogens. Persistent human CMV (HCMV) infection results in a strong increase in the number of virus-specific, quiescent effector-type CD8+ T cells with constitutive cytolytic activity, but the molecular pathways involved in the induction and maintenance of these cells are unknown. We show here that HCMV infection induced acute and lasting changes in the transcriptomes of virus-reactive T cells collected from HCMV-seropositive patients at distinct stages of infection. Enhanced cell cycle and metabolic activity was restricted to the acute phase of the response, but at all stages, HCMV-specific CD8+ T cells expressed the Th1-associated transcription factors T-bet (TBX21) and eomesodermin (EOMES), in parallel with continuous expression of IFNG mRNA and IFN-g–regulated genes. The cytolytic proteins granzyme B and perforin as well as the fractalkine-binding chemokine receptor CX3CR1 were found in virus-reactive cells throughout the response. During HCMV latency, virus-specific CD8+ T cells lacked the typical features of exhausted cells found in other chronic infections. Persistent effector cell traits together with the permanent changes in chemokine receptor usage of virus-specific, nonexhausted, long-lived CD8+ T cells may be crucial to maintain lifelong protection from HCMV reactivation. CD8+ T cells of naive, effector, and memory type were isolated from six latently chronic-infected healthy donors. For RNA isolation and microarray analysis, 3 independent donors and a pool of 3 additional healthy individuals were used. Total RNA of all naive CD8+ T cells was pooled and used as a common reference sample.
Project description:During acute viral infections, naïve CD8+ T cells differentiate into effector CD8+ T cells and, after viral control, into memory CD8+ T cells. Memory CD8+ T cells are highly functional, proliferate rapidly upon reinfection and persist long-term without antigen. In contrast, during chronic infections, CD8+ T cells become “exhausted” and have poor effector function, express multiple inhibitory receptors, possess low proliferative capacity, and cannot persist without antigen. To compare the development of functional memory T cells with poorly functional exhausted T cells, we generated longitudinal transcriptional profiles for each. Naive CD44Lo CD8+ T cells were isolated and sorted from uninfected C57BL/6 mice and H2-Db GP33-specific CD8+ T cells were sorted using MHC-I tetramers at d6, 8, 15, and 30 p.i. with either LCMV Arm or LCMV clone 13. RNA from these CD8+ T cells was processed, amplified, labeled, and hybridized to Affymetrix GeneChip MoGene 1.0 st microarrays
Project description:Chronic hepatitis C virus (HCV) infection is associated with CD8+ T-cell exhaustion characterized by limited effector functions and thus compromised anti-viral activity. Exhausted HCV-specific CD8+ T cells are comprised of memory-like and terminally exhausted CD8+ T-cell subsets. So far, little is not known about the molecular profile and fate of these cells after elimination of chronic antigen stimulation by direct acting antiviral therapy (DAA). Here, we report an antigen-driven molecular core signature underlying exhausted CD8+ T-cell subset heterogeneity in chronic viral infection with a progenitor/progeny relationship of memory-like and terminally exhausted HCV-specific CD8+ T cells via an intermediate stage. Furthermore, transcriptional profiling reveals that the memory-like cells remain after DAA-mediated cure while terminally exhausted HCV-specific CD8+ T-cell subsets are lost. Thus, the memory polarization of the overall HCV-specific CD8+ T-cell response after cure does not result from re-differentiation of exhausted T cells. Consequently, antigen elimination has little impact on the exhausted core signature of memory-like CD8+ T cells that remains clearly different from bona fide T-cell memory. These results identify a molecular signature of T-cell exhaustion that is imprinted like a chronic scar in HCV-specific CD8+ T cells even after HCV cure, highlighting the requirement of re-programming to elicit full effector potential of exhausted T cells.
Project description:Chronic hepatitis C virus (HCV) infection is associated with CD8+ T-cell exhaustion characterized by limited effector functions and thus compromised anti-viral activity. Exhausted HCV-specific CD8+ T cells are comprised of memory-like and terminally exhausted CD8+ T-cell subsets. So far, little is not known about the molecular profile and fate of these cells after elimination of chronic antigen stimulation by direct acting antiviral therapy (DAA). Here, we report an antigen-driven molecular core signature underlying exhausted CD8+ T-cell subset heterogeneity in chronic viral infection with a progenitor/progeny relationship of memory-like and terminally exhausted HCV-specific CD8+ T cells via an intermediate stage. Furthermore, transcriptional profiling reveals that the memory-like cells remain after DAA-mediated cure while terminally exhausted HCV-specific CD8+ T-cell subsets are lost. Thus, the memory polarization of the overall HCV-specific CD8+ T-cell response after cure does not result from re-differentiation of exhausted T cells. Consequently, antigen elimination has little impact on the exhausted core signature of memory-like CD8+ T cells that remains clearly different from bona fide T-cell memory. These results identify a molecular signature of T-cell exhaustion that is imprinted like a chronic scar in HCV-specific CD8+ T cells even after HCV cure, highlighting the requirement of re-programming to elicit full effector potential of exhausted T cells.
Project description:In response to acute infection, naive CD8+ T cells expand, differentiate into effector cells and then contract to a long-lived pool of memory cells after pathogen clearance. During chronic infections or in tumors, CD8+ T cells acquire an “exhausted” phenotype. Here we present genome-wide comparisons of chromatin accessibility and gene expression from endogenous CD8+ T cells responding to acute and chronic viral infection using ATAC-seq and RNA-seq. Acquisition of effector, memory or exhausted phenotypes was associated with stable changes in chromatin accessibility away from the naive T cell state. Regions differentially accessible between functional subsets in vivo were enriched for binding sites of transcription factors known to regulate these subsets, including E2A, BATF, IRF4, T-bet and TCF1. Exhaustion-specific accessible regions were enriched for consensus binding sites for NFAT and Nr4a family members, indicating that chronic stimulation confers a unique accessibility profile on exhausted cells.
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:During acute viral infections, naïve CD8+ T cells differentiate into effector CD8+ T cells and, after viral control, into memory CD8+ T cells. Memory CD8+ T cells are highly functional, proliferate rapidly upon reinfection and persist long-term without antigen. In contrast, during chronic infections, CD8+ T cells become “exhausted” and have poor effector function, express multiple inhibitory receptors, possess low proliferative capacity, and cannot persist without antigen. Exhuasted CD8+ T cells can be further segregated by their expression of the inhibitory cell surface receptor PD-1. We performed transcriptional profiling on both PD-1 High and PD-1 Intermediate H2-Db GP33-specific CD8+ T cells. H2-Db GP33-specific CD8+ T cells were sorted from C57BL/6 mice 30 days p.i. with LCMV clone 13. These cells were then segregated by their expression of the inhibitory cell surface receptor PD-1 into PD-1 High and PD-1 Intermediate subpopulations. We performed transcriptional profiling on these subpopulations.