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:The profiles of H3K27 tri-methylation in CD8+ T cells from LCMV-Armstrong and LCMV-Clone 13 infected mice are known to be distinct from one another. We used CUT&RUN (Cleavage Under Targets and Release Using Nuclease) to analyze these differences in splenic CD8+ T cells of these two infection conditions.
Project description:The transcriptomes of CD8+ T cells from LCMV-Armstrong and LCMV-Clone 13 infected mice are known to be distinct from one another. We used single cell RNA sequencing (scRNA-seq) to analyze the transcriptomic diversity of splenic CD8+ T cells in these two infection conditions at various timepoints after infection.
Project description:The profiles of open chromatin regions of CD8+ T cells from LCMV-Armstrong and LCMV-Clone 13 infected mice are known to be distinct from one another. We used Assay for Transposase-Accessible Chromatin using sequencing at the single cell level (scATAC-seq) to analyze these differences in splenic CD8+ T cells of these two infection conditions at Division 1 post-infection.
Project description:Persistent antigen exposure during chronic viral infection and tumor development drives CD8 T cells into an exhausted, hypofunctional state. Understanding the molecular pathways that enforce T cell exhaustion is critical for improving current immunotherapies. Work from our lab described how the bioactive lipid lysophosphatidic acid (LPA) regulates CD8 T cell function through LPA receptor 5 (LPAR5) signaling. Lpar5–/– CD8 T cells also exhibit enhanced tumor clearance in murine models of melanoma. Importantly, significantly elevated levels of LPA have been identified in individuals with different cancers and persistent viral infections such as HIV, HCV, and HBV. To investigate the role of Lpar5 in the differentiation and maintenance of exhausted CD8 T cells, we utilized the LCMV infection model. In response to infection with LCMV Clone 13, but not Armstrong, one quarter of Lpar5–/– animals succumbed to infection, and this was accompanied by an increased frequency of LCMV-specific Lpar5–/– CD8 T cells maintained in a less terminally exhausted state. Using P14 transgenic mice, we demonstrate that Lpar5 acts in a cell-intrinsic and temporal manner to regulate CD8 T cell accumulation and exhaustion programming during Clone 13 infection. The enhanced accumulation of Lpar5–/– P14 cells during the acute phase of Clone 13 infection appears to be regulated by Lpar5-mediated changes in T cell survival and not through trafficking or proliferation. RNA sequencing analyses and surface phenotyping show that Lpar5 likely regulates CD8 T cell exhaustion through modulation of the CD94/NKG2A inhibitory axis.
Project description:Infection with acute and chronic strains of LCMV (Armstrong (ARM) and Clone 13 (C13), respectively) leads to massive proliferation of monocytic cells contemporaneously with peak of the anti-viral CD8+ T cell response. These cells return to naïve levels following ARM infection. However, during C13 infection these cells are sustained at high levels and gain a T cell suppressive function at day 14 post infection. The mechanisms by which these cells are induced to proliferate and impair T cell function during chronic LCMV infection are largely unknown. To address this, we analyzed gene expression profiles using microarray analysis of purified splenic monocytic cells (CD11b+ Ly6Chi Gr-1low) from naïve mice, or day 14 LCMV ARM or LCMV C13 infected mice.
Project description:Altered CD8 T cell differentiation and functional exhaustion prevent control of chronic virus infection and cancer. Yet, how fate commitment and exhaustion are determined and dynamically modulated throughout persistent infection are unclear. We compared the activation and differentiation of LCMV GP33-specific CD8 TCR transgenic cells (P14) primed at the onset versus in the midst of established persistent LCMV-Clone 13 viral infection. LCMV GP33-specific CD8 TCR transgenic (P14) cells were injected into naïve mice immediately infected with LCMV-Cl13 (Early priming) or into mice that had been infected 21 days earlier with LCMV-Cl13 (Late Priming). Sixty hours post-priming P14 cells were sorted from mice and subjected to RNA seq. We show early primed cells very rapidly exhibit a transcriptional profile of robust activation, effector differentiation and dysfunction, while late primed cells have increased expression of genes involved in memory differentiation and maintenance.