Project description:Single-cell RNA sequencing (scRNA-seq) was used to study the various transcriptional states of individual CD4+ T cells during blood-stage Plasmodium chabaudi infection in mice. This is an experimental model of malaria in which CD4+ T cells are essential for controlling parasite numbers, and which is characterized by concurrent development of Th1 and Tfh cells. We have used Plasmodium-specific TCR transgenic CD4+ T cells to minimise the effects of TCR diversity on Th fate decisions. Activated antigen-specific cells were studied at days 0, 2, 3, 4 and 7. In addition, dendritic cells and monocytes were studied at days 0 and 3. Cell lysis, RT and cDNA preamplification was performed using Fluidigm C1 system.
Project description:Antigen encounter directs CD4+ T cells to differentiate into T-helper or -regulatory cells. This process focuses the immune response on the invading pathogen and limits tissue damage. Mechanisms that govern -helper versus -regulatory fate remain poorly understood. Here, we show that the E3 ubiquitin ligase Cul5 determines fate selection in CD4+ T cells by regulating IL-4 receptor signaling. Mice lacking Cul5 in T cells developed enhanced Th2 and Th9 inflammation and pathophysiological features of atopic asthma upon allergen exposure. Following T cell activation, Cul5 formed a complex with CIS and pJak1. Loss of Cul5 function resulted in reduced ubiquitylation and increased stability of pJak1, elevated STAT6 activity, and a reduced threshold for IL-4 receptor signaling. In keeping with this, Cul5-deficient T cells deviated from Treg to Th9 differentiation in low IL-4 conditions. These data support that Cul5 promotes a tolerogenic T cell fate choice and reduces susceptibility to allergic asthma.
Project description:Cone and rod photoreceptors in human enable daytime color and nighttime dark vision respectively and abnormality in photoreceptor development results in blindness. However, when and how the two photoreceptors are fate-determined during development is largely unknown. Herein, we established a cell atlas for human photoreceptor development, based on single-cell transcriptomic profiling of engineered human retinal organoids engineered to trace the photoreceptor lineages during developmentto monitor the photoreceptor lineages during development. For the first time, we demonstrated the subtypes of photoreceptor precursors based on unsupervised clustering of single-cell transcriptomesbifurcation of cell fate in the photoreceptor precursors, withwith the conespecific expression of molecular marker gene PDE6H ands for cone precursor and rod marker gene NR2E3 differentially expressed among others precursor. Further dissection of transcriptional segregation of the two precursors uncovered PHLDA1 as an intrinsic regulator intrinsic regulator in the fate bifurcation of of the rod-related gene networksphotoreceptor subtypes. Photoreceptor precursors with decreased PHLDA1 yield more cones while reduced the number of rods. The PHLDA1-mediated modification of cell fate can be directed downstream of IGF1 signaling, and exhibited an inhibitory effect on AKT phosphorylation which was associated with cone differentiation., which directed the downstream effects of IGF1 to promote the rod differentiation. Collectively, our data identified PHLDA1 as a novel regulator of fate determination of photoreceptors at the precursor stage, andour study shed lights on the cellular and molecular mechanisms of human photoreceptor precursor specification, and provided a framework to study mechanisms of cell fate determination of human retinal cells.
Project description:Single-cell Transcriptomics Resolves Intermediate Glial Progenitors and Uncovers a Pivotal Determinant of Cell Fate and Gliomagenesis
Project description:Exosomes were isolated from CD4+T cell by ExoQuickTC kit in rheumatoid arthritis patients and controls. Proteomic analysis of CD4+ T-cell-derived exosomes was performed by TMT combined with LC‒MS/MS.
Project description:Inductive signaling interactions between different cell types are a major mechanism for the further diversification of embryonic cell fates. Most blastomeres in the model chordate Ciona robusta become restricted to a single predominant fate between the 64-cell and mid-gastrula stages. The deeply stereotyped and well-characterized Ciona embryonic cell lineages allow the transcriptomic analysis of newly-established cell types very early in their divergence from sibling cell states without the pseudotime inference needed in the analysis of less synchronized cell populations. This is the first ascidian study to use droplet scRNAseq with large numbers of analyzed cells as early as the 64-cell stage when major lineages such as primary notochord first become fate restricted. We identify 59 distinct cell states, including new subregions of the b-line neural lineage and the early induction of the tail tip epidermis. We find that 34 of these cell states are directly or indirectly dependent on MAPK-mediated signaling critical to early Ciona patterning. Most of the MAPK-dependent bifurcations are canalized with the signal-induced cell fate lost upon MAPK inhibition, but the posterior endoderm is unique in being transformed into a novel state expressing some but not all markers of both endoderm and muscle. Divergent gene expression between newly bifurcated sibling cell types is dominated by upregulation in the induced cell type. The Ets family transcription factor Elk1/3/4 is uniquely upregulated in nearly all the putatively direct inductions. Elk1/3/4 upregulation together with Ets transcription factor binding site enrichment analysis enables inferences about which bifurcations are directly versus indirectly controlled by MAPK signaling. We examine notochord induction in detail and find that the transition between a Zic/Ets-mediated regulatory state and a Brachyury/FoxA-mediated regulatory state is unexpectedly late. This supports a ‘broad-hourglass’ model of cell fate specification in which many early tissue-specific genes are induced in parallel to key tissue-specific transcriptional regulators via the same set of transcriptional inputs.
Project description:Antigen encounter directs CD4+ T cells to differentiate into T-helper or -regulatory cells. This process focuses the immune response on the invading pathogen and limits tissue damage. Mechanisms that govern -helper versus -regulatory fate remain poorly understood. Here, we show that the E3 ubiquitin ligase Cul5 determines fate selection in CD4+ T cells by regulating IL-4 receptor signaling. Mice lacking Cul5 in T cells developed enhanced Th2 and Th9 inflammation and pathophysiological features of atopic asthma upon allergen exposure. Following T cell activation, Cul5 formed a complex with CIS and pJak1. Loss of Cul5 function resulted in reduced ubiquitylation and increased stability of pJak1, elevated STAT6 activity, and a reduced threshold for IL-4 receptor signaling. In accordance with this, Cul5-deficient T cells deviated from Treg to Th9 differentiation in low IL-4 conditions. These data support that Cul5 promotes a tolerogenic T cell fate choice and reduces susceptibility to allergic asthma.