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:During acute viral infections, naïve CD4+ T cells differentiate into effector CD4+ T cells and, after viral control, into memory CD4+ T cells. Memory CD4+ T cells are highly functional, proliferate rapidly upon reinfection and persist long-term without antigen. In contrast, during chronic infections, CD4+ T cells become less functional. To compare the development of functional memory T cells with poorly functional T cells from chronic viral infection, we generated longitudinal transcriptional profiles for each. Naive CD44Lo CD4+ T cells were isolated and sorted from uninfected C57BL/6 mice and H2-IAb GP66-specific CD4+ T cells were sorted using MHC-II tetramers at d6, 8, 15, and 30 p.i. with either LCMV Arm or LCMV clone 13. RNA from these CD4+ T cells was processed, amplified, labeled, and hybridized to Affymetrix GeneChip MoGene 1.0 st microarrays.
Project description:Antigen-specific effector CD8+ T cells deficient in Blimp-1 (Prdm1) do not acquire maximal effector functions, evade terminal differentiation, and more rapidly acquire some hallmark properties of memory CD8+ T cells. In this study, we compared the gene expression profiles of wildtype and Prdm1-/- LCMV-specific effector CD8+ T cells to better understand the molecular mechanisms underlying this striking phenotype. DNA microarray analysis was performed of DbGP33-41 and DbNP396-404 tetramer-positive effector CD8+ T cells FACS-sorted at day 8 post-LCMV infection from four independent samples of either Blimp-1 conditional knockout mice (CKO; Blimp-1flox/flox x GranzymeB-cre+) or wildtype (WT) littermate controls.
Project description:Acquisition of effector properties is a key step in the generation of cytotoxic T lymphocytes (CTLs). Here we show that inflammatory signals regulate Dicer expression in CTL, and that deletion or depletion of Dicer in mouse or human activated CD8+ T cells causes upregulation of perforin, granzyme and effector cytokines. Genome-wide analysis of miRNA changes induced by exposure of differentiating CTLs to IL-2 and inflammatory signals identifies miR-139 and miR-150 as components of a miRNA network that controls perforin, eomesodermin (Eomes) and IL-2Ra expression in differentiating CTLs and whose activity is modulated by IL-2, inflammation and antigenic stimulation. Overall our data show that strong IL-2R and inflammatory signals act through Dicer and miRNAs to control the cytolytic program and other aspects of effector CTL differentiation. Comparison of control and Dicer knock-out CTLs differentiated in vitro; Comparison of wild type CTLs differentiated in vitro with or without inflammatory stimuli; Comparison of effector and memory precursor CTLs isolated from mice infected with LCMV-Armstrong
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.
Project description:CD4 and CD8 T cells display functional defects during chronic infection such as loss of certain cytokines. Recent studies have suggested that CD4 T cells may actually gain other functions, however. Here, we analyzed gene expression profiles from LCMV-specific CD4 and CD8 T cells throughout the response to either acute LCMV or chronic LCMV infection. This alllowed us to identify CD4-specific changes during chronic infection compared to acute infection but also revealed shared core regulators between CD4 and CD8 T cells. LCMV-specific CD4 and CD8 T cells were isolated 6, 8, 15 and 30 days post infection with LCMV Armstrong or LCMV clone 13. Naïve CD4 and CD8 T cells were also isolated from naïve mice as comparisons. Four replicates of each sample were hybridized. The only exception is LCMV-specific CD4 T cells isolated 6 days post infection with LCMV-Arm where only three replicates were hybridized.
Project description:At the peak of the CD8 T cell response to acture viral and bacterial infections, expression of the Interleukin-7 Receptor (IL-7R) marks Memory Precursor Effector CD8 T Cells (MPECs) from other Short-Lived Effector CD8 T cells (SLECs), which are IL-7Rlo. This study was designed to determine the gene expression differences between these two subsets of effector CD8 T cells. Experiment Overall Design: This study compared IL-7Rhi and IL-7Rlo LCMV-specific P14 Transgenic CD8 T cells, sorted from LCMV armstrong infected recipient mice 6/7 days after infection. Data includes 3 independent replicates for the IL-7Rhi and IL-7Rlo groups.
Project description:Immune memory cells are poised to rapidly expand and elaborate effector functions upon reinfection. However, despite heightened readiness to respond, memory cells exist in a functionally quiescent state. The paradigm is that memory cells remain inactive due to lack of TCR stimuli. Here we report a unique role of Tregs in orchestrating memory quiescence by inhibiting effector and proliferation programs through CTLA-4. Loss of Tregs resulted in activation of genome-wide transcriptional programs characteristic of potent effectors, and both developing and established memory quickly reverted to a terminally differentiated (KLRG-1hi/IL-7R±lo/GzmBhi) phenotype, with compromised metabolic fitness, longevity, polyfunctionality and protective efficacy. CTLA-4, an inhibitory receptor overexpressed on Tregs, functionally replaced Tregs in trans to rescue Treg-less memory defects and restore homeostasis of secondary mediators as well. These studies present CD28-CTLA-4-CD80/CD86 axis as a novel target to potentially accelerate vaccine-induced immunity and improve T-cell memory quality in current cancer immunotherapies proposing transient Treg-depletion. We used microarray analysis to detail the global programming of gene expression in LCMV GP33-specific CD8 T cells differentiated in the presence or absence of regulatory T cells Differentiation of memory CD8 T cells entails a progressive transition of highly activated effector program to a quiescent memory program. A key question in the field is to understand the factors that aid in the differentiation of memory cells from effector cells. It is a generally accepted paradigm that effector cells transition to a memory state by default after antigen clearance, since TCR stimuli is the key driver of effector programs in CD8 T cells. We hypothesized that the effector to memory transition of CD8 T cells involves active immunological brakes through regulatory T cells (Tregs) that allow the highly activated effector cells to convert into quiescent memory cells. To address this hypothesis, we used FoxP3-DTR mice to deplete Tregs during the window following antigen clearance, during which the effector CD8 T cells convert to long-lived memory cells. To get a deeper understanding of the global transcriptome of CD8 T cells as they transition from an effector to a memory state, we isolated and arrayed the antigen-specific CD8 T cells at day 16 post-infection that have experienced the transitional environment with and without the presence of Tregs.
Project description:In chronic inflammatory diseases of the central nervous system (CNS), immune cells persisting behind the blood-brain barrier are supposed to promulgate local tissue destruction. The drivers of such compartmentalized inflammation remain unclear, but tissue-resident memory T cells (TRM) represent a potentially important cellular player in this process
Project description:In chronic inflammatory diseases of the central nervous system (CNS), immune cells persisting behind the blood-brain barrier are supposed to promulgate local tissue destruction. The drivers of such compartmentalized inflammation remain unclear, but tissue-resident memory T cells (TRM) represent a potentially important cellular player in this process