Epigenetic regulation of the transcriptional program in memory and terminally differentiated CD8+ T cells [HCAFIS_05_Methylation]
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ABSTRACT: Epigenetic mechanisms play a critical role during differentiation of T cells by contributing to the formation of stable and heritable transcriptional patterns. To further study the mechanisms of memory maintenance in CD8+ T cells, we performed genome-wide analysis of DNA methylation, histone marking (H3K9Ac and H3K9me3) and gene expression profiles in naive, effector memory (EM) and terminally differentiated memory (TEMRA) cells. Our results indicate that DNA demethylation and histone acetylation are coordinated to generate the transcriptional program associated with memory cells. Conversely, EM and TEMRA cells share a very similar epigenetic landscape. Nonetheless, the TEMRA transcriptional program predicts an innate immunity phenotype associated with genes never reported in these cells, including several mediators of NK cell activation (VAV3 and LYN) and a large array of NK receptors (KIR2DL3, KIR2DL4, KIR2DL1, KIR3DL1, KIR2DS5, etc.). In addition, we identified up to 161 genes that encode transcriptional regulators, some of unknown function in CD8+ T cells, that were differentially expressed in the course of differentiation. Overall, these results provide new insights into the regulatory networks involved in memory CD8+ T cell maintenance and T cell terminal differentiation.
Project description:Epigenetic mechanisms play a critical role during differentiation of T cells by contributing to the formation of stable and heritable transcriptional patterns. To further study the mechanisms of memory maintenance in CD8+ T cells, we performed genome-wide analysis of DNA methylation, histone marking (H3K9Ac and H3K9me3) and gene expression profiles in naive, effector memory (EM) and terminally differentiated memory (TEMRA) cells. Our results indicate that DNA demethylation and histone acetylation are coordinated to generate the transcriptional program associated with memory cells. Conversely, EM and TEMRA cells share a very similar epigenetic landscape. Nonetheless, the TEMRA transcriptional program predicts an innate immunity phenotype associated with genes never reported in these cells, including several mediators of NK cell activation (VAV3 and LYN) and a large array of NK receptors (KIR2DL3, KIR2DL4, KIR2DL1, KIR3DL1, KIR2DS5, etc.). In addition, we identified up to 161 genes that encode transcriptional regulators, some of unknown function in CD8+ T cells, that were differentially expressed in the course of differentiation. Overall, these results provide new insights into the regulatory networks involved in memory CD8+ T cell maintenance and T cell terminal differentiation.
Project description:Epigenetic mechanisms play a critical role during differentiation of T cells by contributing to the formation of stable and heritable transcriptional patterns. To further study the mechanisms of memory maintenance in CD8+ T cells, we performed genome-wide analysis of DNA methylation, histone marking (H3K9Ac and H3K9me3) and gene expression profiles in naive, effector memory (EM) and terminally differentiated memory (TEMRA) cells. Our results indicate that DNA demethylation and histone acetylation are coordinated to generate the transcriptional program associated with memory cells. Conversely, EM and TEMRA cells share a very similar epigenetic landscape. Nonetheless, the TEMRA transcriptional program predicts an innate immunity phenotype associated with genes never reported in these cells, including several mediators of NK cell activation (VAV3 and LYN) and a large array of NK receptors (KIR2DL3, KIR2DL4, KIR2DL1, KIR3DL1, KIR2DS5, etc.). In addition, we identified up to 161 genes that encode transcriptional regulators, some of unknown function in CD8+ T cells, that were differentially expressed in the course of differentiation. Overall, these results provide new insights into the regulatory networks involved in memory CD8+ T cell maintenance and T cell terminal differentiation.
Project description:Epigenetic mechanisms play a critical role during differentiation of T cells by contributing to the formation of stable and heritable transcriptional patterns. To further study the mechanisms of memory maintenance in CD8+ T cells, we performed genome-wide analysis of DNA methylation, histone marking (H3K9Ac and H3K9me3) and gene expression profiles in naive, effector memory (EM) and terminally differentiated memory (TEMRA) cells. Our results indicate that DNA demethylation and histone acetylation are coordinated to generate the transcriptional program associated with memory cells. Conversely, EM and TEMRA cells share a very similar epigenetic landscape. Nonetheless, the TEMRA transcriptional program predicts an innate immunity phenotype associated with genes never reported in these cells, including several mediators of NK cell activation (VAV3 and LYN) and a large array of NK receptors (KIR2DL3, KIR2DL4, KIR2DL1, KIR3DL1, KIR2DS5, etc.). In addition, we identified up to 161 genes that encode transcriptional regulators, some of unknown function in CD8+ T cells, that were differentially expressed in the course of differentiation. Overall, these results provide new insights into the regulatory networks involved in memory CD8+ T cell maintenance and T cell terminal differentiation.
Project description:Memory T cells are heterogeneous in terms of their phenotype and functional properties. We investigated the molecular profiles of human CD8 naïve (TN), central memory (TCM), effector memory (TEM), and effector memory RA (TEMRA) T cells using gene expression microarrays and phospho-protein-specific intracellular flow cytometry. We demonstrate that TCM have a gene expression and cytokine signaling signature that lies between that of TN and TEM or TEMRA cells, whereas TEM and TEMRA are closely related. Our data define the molecular basis for the different functional properties of central and effector memory subsets. We show that TEM and TEMRA cells strongly express genes with known importance in CD8 T cell effector function. In contrast, TCM are characterized by high basal and cytokine-induced STAT5 phosphorylation, reflecting their capacity for self-renewal. Altogether, our results distinguish TCM and TEM/TEMRA at the molecular level and are consistent with the concept that TCM represent memory stem cells.
Project description:The generation of CD8+ T-cell memory is an important aim of immunization. While several distinct subsets of CD8+ T-cell memory have been described, the lineage relationships between effector (EFF), effector memory (EM) and central memory (CM) T cells remain contentious. Specifically, there is contradictory experimental evidence to support both the linear (Naive>EFF>EM>CM) and progressive differentiation (Naive>CM>EM>EFF) models. In this study, we applied a systems biology approach to examine global transcriptional relationships between the three major CD8+ T cell subsets arising endogenously as a result of vaccination with three different prime-boost vaccine regimens. Differential gene expression analysis and principle component analysis revealed that central memory cells were more closely related to naive T cells than both effector memory and effector cells. When the transcriptional relationships between subsets were enriched in an unbiased fashion with known global transcriptional changes that result when T-cells repeatedly encounter antigen, our analysis favored a model whereby cumulative antigenic stimulation drives differentiation specifically from Naive > CM > EM > EFF. These findings provide an insight into the lineage relationship between mature CD8+ T-cell subsets and will help in the rational design of vaccines aimed at generating effective immune responses against infections and cancer. Effector (EFF), effector memory (EM), central memory (CM) and naive CD8+ T cells from mice spleen. Memory subset arise endogenously as a result of vaccination with three different prime-boost vaccine regimens: DNA-rAd5, rAd5-rAd5 and rAd5-rLCMV.
Project description:As humans age their memory T cell compartment expands due to lifelong exposure to antigens. This expansion is characterized by the presence of terminally differentiated CD8+ T cells (Temra) which possess an NK cell-like phenotype and are associated with chronic inflammatory conditions. Temra cells are predominantly driven by sporadic cytomegalovirus reactivation (CMV) yet their cellular heterogeneity remains understudied. To address this gap we measured their gene expression profiles and conducted single-cell transcriptome analysis. We show that CD8+ Temra cells are highly heterogeneous and describe subsets specific to old age and CMV infection.
Project description:Immune aplastic anemia (AA) is a life-threatening bone marrow (BM) failure disorder driven by an autoimmune T cell attack against the hematopoietic stem and progenitor cells (HSPCs). However, the autoantigen targets and the role of other immune cells are unknown. Here, by combining scRNA+TCRαβ-seq, TCRβ-seq, flow cytometry and plasma cytokine profiling of >250 patients with AA, >250 patients with other hematological disorders and >1,000 healthy controls, we identify NK cells and CD8+ TEMRA cells expressing NK receptors with AA-associated TCRB-seq motifs as the most dysregulated immune cell populations in AA BM. Functional co-culture experiments with scRNA-TCRαβ-seq readout utilizing primary HSPCs and immune cells (in total 55 conditions) provide evidence that NK cells alone cannot kill HSPCs, but sensitize them to CD8+ T cell mediated killing. Furthermore, HSPCs induce strong activation of T cell clones with CD8+ TEMRA NK-like phenotype and AA-associated TCR motifs. To conclude, our results reveal convergent evolution of innate and adaptive immune cells in AA, where NK cells support CD8+ T cell mediated autoimmunity.
Project description:Immune aplastic anemia (AA) is a life-threatening bone marrow (BM) failure disorder driven by an autoimmune T cell attack against the hematopoietic stem and progenitor cells (HSPCs). However, the autoantigen targets and the role of other immune cells are unknown. Here, by combining scRNA+TCRαβ-seq, TCRβ-seq, flow cytometry and plasma cytokine profiling of >250 patients with AA, >250 patients with other hematological disorders and >1,000 healthy controls, we identify NK cells and CD8+ TEMRA cells expressing NK receptors with AA-associated TCRB-seq motifs as the most dysregulated immune cell populations in AA BM. Functional co-culture experiments with scRNA-TCRαβ-seq readout utilizing primary HSPCs and immune cells (in total 55 conditions) provide evidence that NK cells alone cannot kill HSPCs, but sensitize them to CD8+ T cell mediated killing. Furthermore, HSPCs induce strong activation of T cell clones with CD8+ TEMRA NK-like phenotype and AA-associated TCR motifs. To conclude, our results reveal convergent evolution of innate and adaptive immune cells in AA, where NK cells support CD8+ T cell mediated autoimmunity.