Project description:CD4+ T cells play a critical role in sustaining the effector function of CD8+ T cells during chronic viral infection. When CD4+ T cell “help” is absent, CD8+ T cells enter a dysfunctional state, losing their capacity for viral control. Here, we applied spatial transcriptomics to explore cellular localization and potential interaction between key immune cell subsets during chronic LCMV Clone 13 infection.
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.
Project description:CD4+ T cell-derived interleukin 21 (IL-21) sustains CD8+ T cell responses during chronic viral infection, but the helper subset that confers this protection remains unclear. Here, we applied scRNA and ATAC-seq approaches to determine the heterogeneity of CD4+ T cells during LCMV clone 13 infection.
Project description:Regulatory T (Treg) cells act as terminators in the case of T cell immunity during the acute phase of viral infection. However, their roles in chronic viral infection are not completely understood. We compared the phenotype and function of Treg cells during acute and chronic viral infection using lymphocytic choriomeningitis virus-infected mouse models. Chronic infection, unlike acute infection, led to induction of Treg cells and upregulation of various inhibitory receptors. Treg cells isolated from chronically infected mice (chronic Treg cells) displayed greater suppressive capacity for inhibiting T cell proliferation and subsequent cytokine production than those from naM-CM-/ve (naive Treg cells) or acutely infected mice (acute Treg cells). These gene expression profiles provided evidence that chronic Treg cells display characteristics distinct from either naive or acute Treg cells. Mouse splenic CD4+CD25+ regulatory T cells were analyzed at 0 day and 16 day after acute or chronic viral infection with LCMV Arm or CL13, respectively.
Project description:CD4+ T cells play a critical role in sustaining the effector function of CD8+ T cells during chronic viral infection. When CD4+ T cell “help” is absent, following transient CD4+ T cell depletion, CD8+ T cells enter a dysfunctional state, losing their capacity for viral control. Here, we applied scRNA-seq to determine the CD4+ T cell subsets that repopulate following transient CD4+ T cell depletion, during LCMV Clone 13 infection.
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:Chronic viral infections caused by HIV in humans or LCMV in mice are characterized by immunodeficiency and chronic inflammation. During chronification, T cells progressively lose effector functions, a process associated with immunoregulatory pathways and known as T-cell exhaustion. A link between ‘exhaustive’ T-cell reprogramming and chronic inflammation has not been established. Using a systems biology approach we demonstrate in HIV and LCMV infection that TNF, a prototypical mediator of chronic inflammation, functions upstream of major immunoregulatory pathways in T cells during chronic viral infection. In vivo blockade of TNFR-signaling interferes with the exhaustive T-cell program during chronic infection and reduces viral loads by several log. Continuous TNFR-signaling during disease progression towards chronic infection seems to be causative for T-cell exhaustion and an important link between immunodeficiency and chronic inflammation. TNF blockade might represent a novel therapeutic option during late stage infections caused by HIV and other virus causing chronic infections. TNF stimulation of CD4+ T cells to generate a CD4+ T-cell specific RNA-fingerprint
Project description:CD4+ T cells play a critical role in sustaining the effector function of CD8+ T cells during chronic viral infection. When CD4+ T cell “help” is absent, CD8+ T cells enter a dysfunctional state, losing their capacity for viral control. However, when CD4+ T cell help is present, a heterogenous population of virus-specific CD8+ T cells are present. Here, we applied scRNA-seq to distinguish CD8+ T cell heterogeneity during LCMV Clone 13 infection.
