Transcriptomic characterisation of haematopoietic stem and progenitor cells from adult human spleen

Haematopoietic stem and progenitor cells (HSPCs), the precursors of all blood cells, reside predominantly in the bone marrow. Yet, a small proportion (<1%) of phenotypic HSPCs is also found in extramedullary tissues, such as spleen, where they contribute to blood production under stress conditions. However, the detailed characterization of extramedullary HSPCs remains poor. Here, we analyse the single-cell composition of the adult human HSPC pool within the spleen from two patients with hereditary spherocytosis (HS), a disorders causing abnormal red blood cells. 10x scRNA-seq of CD19- CD34+ HSPCs was paired with single-cell functional analysis using most immature haematopoietic stem cells and multipotent progenitors (HSC/MPPs). We find that HSC/MPPs from HS spleens have a stronger transcriptional and functional bia towards the erythroid lineage than control sample. Overall design: Spleen cells from two patients (1 female, 1 male) were stained with a customised catalogue of TotalSeqA (biolegend), CD19- CD34+ cells were sorted by flow cytometry and pooled in a 1:1 ratio before library preparation with the 10x sequencing v3.1 protocol