CD97 is differentially expressed on murine hematopoietic stem-and progenitor-cells

Area of Science:

• Hematology
• Cell Biology
• Immunology

Background:

• CD97, an epidermal growth factor-seven transmembrane (EGF-TM7) family member, is broadly expressed on hematopoietic cells.
• Investigating CD97 expression on hematopoietic stem and progenitor cells (HSC/HPC) is crucial for understanding hematopoiesis.

Purpose of the Study:

• To investigate the differential expression of CD97 on murine hematopoietic stem and progenitor cells.
• To correlate CD97 expression levels with functional characteristics of HSC/HPC.

Main Methods:

• Flow cytometry was used to analyze CD97 expression on bone marrow cells from BALB/c, C57BL/6, and DBA/1 mice.
• Functional assays including progenitor cell assays, cobblestone area forming cell assays, and bone marrow transplantation were performed.

Main Results:

• Three distinct CD97 populations (CD97(HI), CD97(INT), CD97(NEG)) were identified in murine bone marrow.
• CD97(INT) cells showed radioprotective capacity and cobblestone area forming cell activity, while CD97(NEG) cells were enriched for CFU-GM colony-forming capacity.
• Specific CD97 phenotypes (e.g., CD97(INT)c-Kit(HI)) were associated with HSC activity and enrichment.

Conclusions:

• CD97 expression is a reliable marker for distinguishing HSCs from committed progenitor cells.
• The CD97(INT) population harbors HSC activity, whereas CD97(NEG) cells contain committed progenitor activity.
• The CD97(INT)c-Kit(HI) phenotype offers a promising strategy for rapid and efficient purification of murine HSCs.