Project description:Understanding the response of memory CD8 T cells to persistent antigen re-stimulation and the role of CD4 T cell help is critical to the design of successful vaccines for chronic diseases. However, studies comparing the protective abilities and qualities of memory and naïve cells have been mostly performed in acute infections, and little is known about their roles during chronic infections. Herein, we show that memory cells dominate over naïve cells and are protective when present in large enough numbers to quickly reduce infection. In contrast, when infection is not rapidly reduced, memory cells are quickly lost, unlike naïve cells. This loss of memory cells is due to (i) an early block in cell proliferation, (ii) selective regulation by the inhibitory receptor 2B4, and (iii) increased reliance on CD4 T cell help. These findings have important implications towards the design of T cell vaccines against chronic infections and tumors. 16 samples are analyzed: 3 replicates of secondary effector CD8 P14 T cells at day 8 post-acute lymphocytic choriomeningitis virus (LCMV) infection; 4 replicates of secondary effector CD8 P14 T cells at day 8 post-chronic LCMV infection; 4 replicates of primary effector CD8 P14 T cells at day 8 post-acute LCMV infection; and 5 replicates of primary effector CD8 P14 T cells at day 8 post-chronic LCMV infection.
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: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.
Project description:We processed single cell RNA-Sequencing using 10X Genomics platform to study the population dynamics of LCMV antigen specific CD8+ T cells during early phase of acute and chronic infection.
Project description:The goal of this study was to identify the molecular programming using ATAC-seq of CD8 T cells responding to different viral infections. Mice were infected with either LCMV Armstrong to model an acute infection or LCMV Clone-13 to model a chronic infection. At various time points following infection, virus-specific CD8 T cells were purified and ATAC-seq performed. These data identify the changes in chromatin accessibility associated with acute infections and the establishment of functional memory versus those accessibility changes associated with chronic infection.
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:Regulatory T cells (Tregs) play a cardinal role in the immune system by suppressing detrimental autoimmune responses, but their role in acute and chronic infectious diseases remains unclear. We recently demonstrated that IFN- receptor (IFNAR) signaling promotes Treg function in autoimmunity. To dissect the functional role of IFNAR-signaling in Tregs during acute and chronic viral infection, we infected Treg-specific IFNAR deficient (IFNARfl/flxFoxp3YFP-Cre) mice with LCMV Armstrong and Clone-13. In both models, IFNARfl/flxFoxp3YFP-Cre mice Tregs expressed enhanced expression of Treg associated activation antigens. The enhanced activated phenotype was also seen when we compared the transcriptomes of IFNARfl/flxFoxp3YFP-Cre and wild type (WT) Tregs by RNA-Seq on day 25-post Clone-13 infection. LCMV-specific CD8+ T cells from IFNARfl/flxFoxp3YFP-Cre mice produced less antiviral IFN and TNF in both acute and chronic LCMV. In the chronic model, the numbers of anti-viral effector and memory CD8+ T cells were decreased in IFNARfl/flxFoxp3YFP-Cre mice and the effector CD4+ and CD8+ T cells exhibited a phenotype compatible with enhanced exhaustion. IFNARfl/flxFoxp3YFP-Cre mice cleared Armstrong infection normally, but had higher viral titers in sera, kidneys and lungs than WT mice during chronic infection. Thus, type I IFN signaling in Tregs is context-dependent, resulting in enhanced suppressor function in some models of autoimmunity, but decreased suppressor function in acute and chronic viral infection.
Project description:Thymic stromal lymphopoietin (TSLP) is a cytokine that acts directly on CD4+ T cells and dendritic cells to promote progression of asthma, atopic dermatitis, and allergic inflammation. However, a direct role for TSLP in CD8+ T-cell primary responses remains controversial and its role in memory CD8+ T-cell responses to secondary viral infection is unknown. Here, we investigate the role of TSLP in both primary and recall responses using two different viral systems. Interestingly, TSLP limited the primary CD8+ T cell response to influenza but did not affect T cell function nor significantly alter the number of memory CD8+ T cells generated after influenza infection. However, TSLP inhibited memory CD8+ T cell responses to secondary viral infection with influenza or acute systemic LCMV infection. These data reveal a previously unappreciated role for TSLP on recall CD8+ T cell responses in response to viral infection, findings with potential translational implications.