Expanding Hematopoietic Stem Cell pool through Fine tuning of Tpo receptor with diabodies.

Class I cytokine receptors such as Thrombopoietin receptor (MPL) are dimers, but it is unclear whether remodeling receptor dimer topology is a viable strategy to "tune" signaling output. We utilized diabodies (DA) as surrogate ligands in a prototypical dimeric receptor-ligand system, the cytokine Thrombopoietin (TPO) and its receptor (TpoR), to dimerize TpoR ectodomains in non-native architectures. Diabody-induced signaling amplitudes varied from full to minimal agonism. Here we describe a single-cell transcriptome analysis of 659 human Hematopoietic Stem Cells cultured with different DA. We find several difference between differentiation and activation of signaling pathways compared to TPO. Overall design: Examination of single cells transcriptome of HSC culture treated with different TPO agonists or antagonists.