Project description:In this study, we investigated somatic mutations in T cells in patients with various hematological disorders. To analyze immune cell phenotypes with somatic mutations, we performed scRNA+TCRab sequencing from 9 patients with chronic GVHD and clonal expansions of CD4+ or CD8+ T cells based on T cell receptor sequencing. CD45+ PBMCs (lymphocytes and monocytes) were sorted with BD Influx cell sorter and subjected to sequencing with Chromium VDJ and Gene Expression platform (v1.1, 10X Genomics). Sequencing was performed with Novaseq 6000 (Illumina). The immune cell phenotypes were compared to healthy controls processed in the same laboratory (accession number E-MTAB-11170). Due to data privacy concerns, the raw sequencing data is in the European Genome-Phenome Archive (EGA) under accession code [xxxx] and can be requested through the EGA Data Access Committee.
Project description:Embryonic genome activation (EGA) marks the onset of embryonic program and enables the transition toward the first lineage specification. However, the molecular features of EGA and the transcription factors (TFs) orchestrating this process remain unclear. Here, by performing single-cell RNA-seq on bovine embryos, we reveal that major EGA is asynchronously initiated among blastomeres at the 8-cell stage. Integrative analyses reveal distinctive protein accumulation compared to transcription and translation activation during bovine EGA. Furthermore, we investigate the role of SP1, a TF activated at the minor EGA stage, with motifs enriched in accessible chromatin during major EGA stage in bovine and human embryos. SP1 deficiency leads to morula arrest in bovine and impairs EGA in human embryos. Multi-omics analysis demonstrates that SP1 promotes early lineage gene expression by modulating nearby chromatin states in bovine and directly targets key EGA genes in human embryos. Together, our study delineates the dynamics of bovine EGA and uncovers the conserved and species-specific roles of SP1 in regulating EGA and early development in mammals.
Project description:Clonal memory, a cellular property inherited across at least two divisions, has emerged as a key driver of cell heterogeneity. To uncover its roles in human haematopoiesis, we developed high-resolution ex vivo tools to track both division and fate commitment of individual primary human haematopoietic stem and progenitor cells (HSPCs). We show that human HSPCs display a clonal memory of division, as cells descending from the same ancestor cell divide synchronously over multiple generations. In parallel, HSPCs inherit a clonal memory of fate commitment, independently of lineage identity. Both forms of clonal memory persist over at least two divisions, across different HSPC commitment stages and cell culture conditions. In contrast, malignant haematopoiesis exhibits lower synchronicity, revealing a disruption of clonal memory in leukemic cells. Epigenetic remodelling using a bromodomain inhibitor partially restore the clonal memory in division in leukemic HSPCs, highlighting the plasticity of this trait and its potential for therapeutic modulation. Our findings position clonal memory as a key regulator of human haematopoietic stem cell behaviour. Demonstrating that clonal memory can be modulated opens new avenues for tuning cell heterogeneity in healthy and pathological tissues.
Project description:The study will measure blood population dynamics in abnormal human haematopoiesis in patients with clonal blood stem cell disorders.
