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+ 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 mount an accelerated response upon antigen re-challenge but are heterogeneous in phenotype and function. Therefore, traditionally memory T cells were classified into central memory (TCM), effector memory (TEM) and terminally differentiated effector memory (TEMRA) cells based on the expression of lymph node homing receptors and CD45 splice variants. However, findings on functional heterogeneity even within these subsets demonstrated the need for more suitable markers to match phenotype and function during T cell differentiation. To improve functional classification of human CD4+ memory T cells we applied bulk and single gene expression profiling and identified a set of surface markers, KLRB1, KLRG1, GPR56 and KLRF1, which facilitate classification into subsets with “low”, “high” or “exhausted” cytokine production. Highest level production of multiple cytokines was observed in T cells co-expressing KLRB1 with KLRG1 and/or GPR56 while additional KLRF1 expression was associated with a decline in cytokine production. The superiority of using KLRF1 expression to define exhausted cytokine producers compared to classical TEMRA identification was best exemplified for intrahepatic T cells in patients with inflammatory liver diseases. These data open up new opportunities for monitoring and treatment of chronic inflammatory diseases driven by cytokine producing CD4+ memory T cells.
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.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes