Agents for promoting the growth of hematopoietic stem cells

摘要

The inventors found that by administering an agonistic antibody (VB22B sc(Fv)2) with a reduced molecular weight against TPO receptor, human megakaryocyte-specific differentiation is induced (platelet progenitor cells are increased), hematopoietic stem cells (CD34-positive cells) derived from human cord blood are engrafted, and multilineage blood progenitor cells are significantly increased. TPO or TPO receptor agonist can be used as a proliferation promoter of hematopoietic CD34-positive cells or an engraftment promoter in the bone marrow, in which an effect can be expected only by single administration (without concomitant administration of G-CSF or erythropoietin) after engraftment of hematopoietic stem cells (particularly engraftment of cord blood). Further, it can be used as a multilineage hematopoietic progenitor cell proliferation and/or differentiation promoter and a multilineage hematopoietic ability restoration promoter.