Precursors of human CD4+ cytotoxic T lymphocytes identified by single-cell transcriptome analysis [10X genomics]
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ABSTRACT: CD4+ cytotoxic T lymphocytes (CD4-CTLs) have been reported to play a protective role in several viral infections. However, little is known in humans about the biology of CD4-CTL generation, their functional properties, heterogeneity and clonal diversity, especially in relation to other well-described CD4+ memory T cell subsets. We performed single-cell RNA-seq in over 9000 cells to unravel CD4-CTL heterogeneity, transcriptional profile and clonality in humans. The single-cell differential gene expression analysis, revealed a spectrum of known transcripts, including several linked to cytotoxic and co-stimulatory function, and transcripts of unknown cytotoxicity-related function that are expressed at higher levels in the TEMRA subset, which is highly enriched for CD4-CTLs, compared to cells in the central and effector memory subsets (TCM, TEM). Simultaneous T cells antigen receptor (TCR) analysis in single-cells and bulk subsets revealed that CD4-TEMRA cells show marked clonal expansion compared to TCM and TEM cells and that the majority of CD4-TEMRA were dengue virus (DENV)-specific in subjects with previous DENV infection. The profile of CD4-TEMRA was highly heterogeneous across subjects, with four distinct clusters identified by the single-cell analysis. Most importantly, we identified distinct clusters of CD4-CTL effector and precursor cells in the TEMRA subset; the precursor cells shared TCR clonotypes with CD4-CTL effectors and were distinguished by high expression of the interleukin-7 receptor. Our identification of a CD4-CTL precursor population may allow further investigation of how CD4-CTLs arise in humans and thus could provide insights into the mechanisms that may be utilized to generate durable and effective CD4-CTL immunity.
Project description:CD4+ cytotoxic T lymphocytes (CD4-CTLs) have been reported to play a protective role in several viral infections. However, little is known in humans about the biology of CD4-CTL generation, their functional properties, heterogeneity and clonal diversity, especially in relation to other well-described CD4+ memory T cell subsets. We performed single-cell RNA-seq in over 9000 cells to unravel CD4-CTL heterogeneity, transcriptional profile and clonality in humans. The single-cell differential gene expression analysis, revealed a spectrum of known transcripts, including several linked to cytotoxic and co-stimulatory function, and transcripts of unknown cytotoxicity-related function that are expressed at higher levels in the TEMRA subset, which is highly enriched for CD4-CTLs, compared to cells in the central and effector memory subsets (TCM, TEM). Simultaneous T cells antigen receptor (TCR) analysis in single-cells and bulk subsets revealed that CD4-TEMRA cells show marked clonal expansion compared to TCM and TEM cells and that the majority of CD4-TEMRA were dengue virus (DENV)-specific in subjects with previous DENV infection. The profile of CD4-TEMRA was highly heterogeneous across subjects, with four distinct clusters identified by the single-cell analysis. Most importantly, we identified distinct clusters of CD4-CTL effector and precursor cells in the TEMRA subset; the precursor cells shared TCR clonotypes with CD4-CTL effectors and were distinguished by high expression of the interleukin-7 receptor. Our identification of a CD4-CTL precursor population may allow further investigation of how CD4-CTLs arise in humans and thus could provide insights into the mechanisms that may be utilized to generate durable and effective CD4-CTL immunity.
Project description:CD4+ cytotoxic T lymphocytes (CD4-CTLs) have been reported to play a protective role in several viral infections. However, little is known in humans about the biology of CD4-CTL generation, their functional properties, heterogeneity and clonal diversity, especially in relation to other well-described CD4+ memory T cell subsets. We performed single-cell RNA-seq in over 9000 cells to unravel CD4-CTL heterogeneity, transcriptional profile and clonality in humans. The single-cell differential gene expression analysis, revealed a spectrum of known transcripts, including several linked to cytotoxic and co-stimulatory function, and transcripts of unknown cytotoxicity-related function that are expressed at higher levels in the TEMRA subset, which is highly enriched for CD4-CTLs, compared to cells in the central and effector memory subsets (TCM, TEM). Simultaneous T cells antigen receptor (TCR) analysis in single-cells and bulk subsets revealed that CD4-TEMRA cells show marked clonal expansion compared to TCM and TEM cells and that the majority of CD4-TEMRA were dengue virus (DENV)-specific in subjects with previous DENV infection. The profile of CD4-TEMRA was highly heterogeneous across subjects, with four distinct clusters identified by the single-cell analysis. Most importantly, we identified distinct clusters of CD4-CTL effector and precursor cells in the TEMRA subset; the precursor cells shared TCR clonotypes with CD4-CTL effectors and were distinguished by high expression of the interleukin-7 receptor. Our identification of a CD4-CTL precursor population may allow further investigation of how CD4-CTLs arise in humans and thus could provide insights into the mechanisms that may be utilized to generate durable and effective CD4-CTL immunity.
Project description:CD4+ cytotoxic T lymphocytes (CD4-CTLs) have been reported to play a protective role in several viral infections. However, little is known in humans about the biology of CD4-CTL generation, their functional properties, heterogeneity and clonal diversity, especially in relation to other well-described CD4+ memory T cell subsets. We performed single-cell RNA-seq in over 9000 cells to unravel CD4-CTL heterogeneity, transcriptional profile and clonality in humans. The single-cell differential gene expression analysis, revealed a spectrum of known transcripts, including several linked to cytotoxic and co-stimulatory function, and transcripts of unknown cytotoxicity-related function that are expressed at higher levels in the TEMRA subset, which is highly enriched for CD4-CTLs, compared to cells in the central and effector memory subsets (TCM, TEM). Simultaneous T cells antigen receptor (TCR) analysis in single-cells and bulk subsets revealed that CD4-TEMRA cells show marked clonal expansion compared to TCM and TEM cells and that the majority of CD4-TEMRA were dengue virus (DENV)-specific in subjects with previous DENV infection. The profile of CD4-TEMRA was highly heterogeneous across subjects, with four distinct clusters identified by the single-cell analysis. Most importantly, we identified distinct clusters of CD4-CTL effector and precursor cells in the TEMRA subset; the precursor cells shared TCR clonotypes with CD4-CTL effectors and were distinguished by high expression of the interleukin-7 receptor. Our identification of a CD4-CTL precursor population may allow further investigation of how CD4-CTLs arise in humans and thus could provide insights into the mechanisms that may be utilized to generate durable and effective CD4-CTL immunity.
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:CD4+ T-cell help is required for the generation of CD8+ cytotoxic T lymphocyte (CTL) memory. We here reveal how “help” signals delivered during priming impact memory differentiation of CTLs, as informed by genome-wide analyses. “Help” signals promoted the IL-15-dependent maintenance of central memory (TCM) cells. However, they had a much larger impact on the generation of effector memory (TEM) cells and their gene expression program . CD4+ T-cell help created TEM cells that produced Granzyme B and IFNg after antigen-independent recall with IL-12 and IL-18. Furthermore, “helped” memory CTLs expressed the effector program characteristic of “helped” primary CTLs upon recall with MHC class I-restricted antigen only, due to both epigenetic imprinting and sustained mRNA expression of relevant genes . Thus, CD4+ T-cell help delivered during priming creates CD8+ TEM cells with innate and help-independent recall capacities.
Project description:Accumulating evidence demonstrates that CD8 T cells contribute to protection from severe DENV disease and vaccine efficacy. Nevertheless, the molecular programs associated with DENV-specific CD8 T cell subsets have not been defined. Here, we studied the transcriptomic profiles of human DENV-specific CD8 T cells isolated after stimulation with DENV epitopes from donors that have been infected with DENV multiple times and should therefore associated with significant levels of adaptive immunity. DENV-specific CD8 T cells mainly consist of effector memory subsets, namely Tem and Temra which enact specific gene expression profiles upon stimulation with cognate antigens. DENV-specific CD8 T cell subsets in general, and Temra cells in particular, are fully activated and polyfunctional, yet associated with relatively narrow transcriptional responses and TCR repertoires. This study provides the first transcriptomic definition of DENV-specific activated human CD8 T cell subsets and defines a bench mark profile that vaccine-specific response could aim to reproduce.
Project description:Evaluation of transcriptional changes following stimulation of naïve, TCM, TEM and TEMRA CD8+ T cell subsets confirmed that AB248 recapitulated the expected IL-2 signature with high fidelity
Project description:The development of T cells has been characterized as taking place over three stages: naïve (Tn), central memory (Tcm), and effector memory (Tem) cells. Recently, stem cell memory T cells (Tscm) were found to be the least-developed memory subset. We performed detailed analysis of the gene expression of human CD4+ T cells with clear distinction of the Tn, Tscm, Tcm, and Tem stages. We sorted Tn, Tscm, Tcm, and Tem CD4+ T cells from the peripheral blood of six healthy volunteers to see the differences of gene expression between each developmental stage.
Project description:Naive, central memory (TCM), effector memory (TEM), and terminally differentiated effector memory RA (TEMRA, CD8+ only) T cell subsets were FACS separated from PBMC samples of four human donors using CCR7 and CD45RA as distinguishing cell surface markers. Samples were split and either immediately isolated, or incubated for 42-48 hours with anti-CD3/CD28 beads for ex-vivo stimulation.
Project description:Naive, central memory (TCM), effector memory (TEM), and terminally differentiated effector memory RA (TEMRA, CD8+ only) T cell subsets were FACS separated from PBMC samples of four human donors using CCR7 and CD45RA as distinguishing cell surface markers. Samples were split and either immediately isolated, or incubated for 42-48 hours with anti-CD3/CD28 beads for ex-vivo stimulation and processed for ATAC-seq.