[Preliminary study on human mature placenta tissue-derived hematopoietic stem/progenitor cells]

Area of Science:

• Stem cell biology
• Hematology
• Regenerative medicine

Background:

• Cord blood (CB) is used for hematopoietic reconstitution but has limitations in adults due to low cell numbers.
• Adult patients often require higher cell doses than typically available from a single CB unit.

Purpose of the Study:

• To investigate the proliferative and differentiation potential of hematopoietic stem/progenitor cells from human placenta tissue (PT) in vitro.
• To evaluate PT as a novel source for hematopoietic stem cell transplantation.

Main Methods:

• Isolation and characterization of CD34(+) cells from human mature placenta tissue using enzyme digestion and flow cytometry.
• Long-term in vitro culture of PT-derived mononuclear cells (MNCs) and CB MNCs without cytokines.
• Weekly nucleated cell counts for 14 weeks and Colony-Forming Cell (CFC) counts for 2 weeks.

Main Results:

• Placenta tissue (PT) showed higher yields of CFCs (CFU-GM, BFU-E) and a greater percentage of CD34(+) and CD34(+)/CD38(-) cells compared to cord blood (CB).
• PT-derived MNCs exhibited superior survival and proliferation in long-term culture, increasing twofold, outperforming CB-derived cells.
• Placenta-derived cells demonstrated higher viability and expansion potential under culture conditions.

Conclusions:

• Placenta tissue represents a viable alternative source of hematopoietic stem and progenitor cells.
• Placenta-derived cells are more primitive and possess greater expansion capacity, suggesting their suitability for clinical stem cell transplantation.
• The placenta may function as an additional hematopoietic organ during human development.