Dr. Yanhua Li is engaged in the research on the development, differentiation and functional regulation of stem cells, lineage reprogramming to obtain hematopoietic cells, and regeneration and repair strategies for hematopoietic and intestinal injury. She has successively undertaken more than 10 scientific research projects from the National Key R&D Program, the National Natural Science Foundation of China, and the Beijing Natural Science Foundation. She has published more than 60 papers in journals such as Cell Stem Cell, Biomaterials, Theranostics, Stem Cell Reports, Blood, Stem Cells, etc.

Topic title: Manufacturing of hematopoietic cells: From 2D to 3D organoid culture

Abstract:

Hematopoietic stem and progenitor cell (HSPC）transplantation and blood transfusion have been widely used in clinic for treatment of multiple diseases. However, these therapeutic cells are harvested from healthy donors, which greatly limit the application of these medical procedures. It’s urgent to develop the manufacturing technique of hematopoietic cells to get out of the donation-dependent cell collection manner. We aimed to generate large numbers of human HSPCs, megakaryocytes (MKs) and platelets via three paths in vitro, including expansion and differentiation of cord blood (CB) stem cells, differentiation of pluripotent stem cells, and lineage cell reprogramming. By using phenotype-based screening strategy, we discovered several small molecules those can significantly improve the expansion efficiency of CB HSPCs and MK progenitor cells. However, the limited number of HSPCs in a single unit of CB is still one of the major challenges in clinic. we also chose human embryonic stem cells (hESCs) as seed cells to generate hematopoietic cells. We improved the monolayer induction protocol to a defined three-dimensional (3D) and sphere-like differentiation models for hematopoietic progenitor cell (HPC) and MK production by using dynamic culture condition. The percentage and number of HPCs derived from hESCs are easily reduced in 2D or 3D embryonic body-like culture system. Thus, we further developed a hematopoietic organoid culture protocol with Matrigel, multiple cytokines and 5 small molecules by using hESCs as seed cells. Notably, these hematopoietic organoids can be maintained and produce blood cells for over 20 days. Moreover, the hESCs-derived hematopoietic organoids presented radiation-induced HPC damage and regeneration effect. Our data indicates that in vitro manufacturing of human hematopoietic organoids from hESCs helps to modelling hematopoietic and blood diseases, screen and test drug candidates prior to clinical trials or continuously generate blood cells for therapeutic application.