Human mesenchymal stromal cells express CD14 cross-reactive epitopes.

Area of Science:

• Cell Biology
• Immunology
• Stem Cell Research

Background:

• Mesenchymal stromal cells (MSCs) are defined by minimal criteria including CD73, CD90, CD105 expression and lack of hematopoietic markers.
• Previous studies have not extensively investigated potential cross-reactivity of antibodies with MSCs.

Purpose of the Study:

• To investigate the cross-reactivity of CD14 antibodies with bone marrow- and placenta-derived MSCs.
• To identify reliable antibodies for distinguishing MSCs from other cell types.

Main Methods:

• Isolation and expansion of MSCs from human bone marrow and placenta.
• Characterization using quantitative RT-PCR, flow cytometry, and immunocytochemistry.
• Testing of four different CD14 monoclonal antibody clones for MSC staining, with cell sorting for enrichment.

Main Results:

• Three of four CD14 antibody clones showed staining on MSCs, indicating cross-reactivity.
• MSCs did not express CD14 transcripts or protein.
• CD14 antibody clone MΦP9 effectively discriminated between monocytes and MSCs, unlike other clones tested.

Conclusions:

• Bone marrow- and placenta-derived MSCs do not express CD14.
• Specific CD14 antibody clones exhibit cross-reactivity, necessitating careful selection for accurate MSC characterization.
• The MΦP9 clone provides a more efficient means to differentiate monocytes from MSCs.