Project description:We leverage the extraordinary molecular diversity of modified heparan sulfate (HS) glycans 8 to establish cellular glycotypes, defined by binding patterns of a panel of flow-cytometry compatible single-chain variable fragment antibodies (scFvs) specific for differentially modified HS. We find distinct glycotypes between closely related hematopoietic progenitors and lineages. The glycotypes of murine and human hematopoietic stem and progenitor cells (HSPCs) reveal dynamic yet similar HS modification patterns in vivo and in vitro, including along megakaryocyte and erythrocyte differentiation. Prospective HS scFv-based sorting identifies new cellular subtypes from both immunophenotypic megakaryocyte-erythrocyte progenitors and heterogeneous pools of HSPCs, thus offering additional discriminative power beyond conventional CD markers. Mechanistically, single-cell RNAseq revealed that a heptad of HS-related genes participate in megakaryocyte-erythrocyte fate determination and are reflective of the HS epitope recognized by specific HS scFvs. In summary, HS glycotyping establishes a role for HS modification patterns in hematopoietic lineage differentiation in mouse and human, and provides an orthogonal approach to define and isolate viable cell types across different cell lineages and species at unprecedented resolution.
