Establishment of culture system for hematopoietic stem cells under completely protein-free conditions

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K21612
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 54:Internal medicine of the bio-information integration and related fields
• Research Institution: University of Tsukuba
• Principal Investigator: Yamazaki Satoshi 筑波大学, 医学医療系, 教授 (50625580)
• Project Period (FY): 2020-07-30 – 2022-03-31
• Keywords: 無タンパク質培養 / 造血幹細胞

Outline of Final Research Achievements

The discovery that serum components and albumin can be replaced by polyvinyl alcohol (PVA) for hematopoietic stem cells (HSCs) in bone marrow in vivo has made it possible to amplify HSCs ex vivo. The discovery of PVA revealed that oxidation and degradation of proteins in the culture medium, as well as impurities contained in trace amounts in purified albumin and cytokines, inhibit the undifferentiated nature of HSCs. Based on these experimental results, the applicant considered that it is essential to establish complete protein-free culture conditions in order to prevent the reduction of the function and amplification of HSCs. During the course of this study, we were able to maintain stemness for a long period of time by culturing HSCs in vivo under complete protein-free conditions.

Free Research Field

幹細胞生物学

Academic Significance and Societal Importance of the Research Achievements

本研究課題は造血幹細胞の増幅率を現行の培養システムの10倍もしくは100倍以上向上させる目的は勿論であるが、培養条件にはタンパク質が一切存在しない完全化学物質で構成させた環境下において達成することが大きな目標であった。一方で非常にチャレンジングであった。しかし、本研究は成功し細胞治療の研究分野へ波及することになり世間一般的は波紋や期待度は大きいと言える。