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. Examination of single cells transcriptome of HSC culture treated with different TPO agonists or antagonists.