Characterization of human bone marrow long-term cultures

Area of Science:

• Hematology
• Stem Cell Biology
• Biomedical Engineering

Background:

• Simulating the native hematopoietic microenvironment is crucial for understanding blood cell development.
• Human bone marrow bony matrix contains stromal cells that support hematopoiesis.
• Previous studies have explored in vitro models for hematopoietic research.

Purpose of the Study:

• To evaluate the capacity of human bone marrow bony matrix cultures to support hematopoietic precursor cells.
• To investigate the effects of X-irradiation and autologous cell addition on the hematopoietic microenvironment in vitro.
• To assess the long-term maintenance of granulocyte-macrophage colony-forming units (CFU-gm) in these cultures.

Main Methods:

• Human sternal bone marrow curettings (bony matrix) were cultured long-term.
• Cultures were established with and without autologous bone marrow single cell suspensions.
• Cells were harvested weekly and assayed for CFU-gm.
• X-irradiation and hydrocortisone treatments were applied to assess their impact.

Main Results:

• Bone marrow bony matrix alone did not sustain CFU-gm production but initially recruited cells.
• X-irradiation of the matrix impaired hematopoietic support, but this was reversible with autologous cells.
• Hydrocortisone did not affect CFU-gm maintenance, while fresh marrow replenished cultures for 10 weeks.

Conclusions:

• Human bone marrow stroma is more sensitive to X-irradiation in vitro than in vivo.
• The in vitro hematopoietic microenvironment provided by bony matrix is less effective than in vivo for maintaining hematopoietic precursor cells.
• Long-term culture systems require replenishment with fresh autologous cells for sustained hematopoietic support.