Are mesenchymal stromal cells immune cells?

Area of Science:

• Immunology
• Cell Biology
• Regenerative Medicine

Background:

• Mesenchymal stromal cells (MSCs) are recognized for their therapeutic potential in immunological diseases.
• While initially identified as mesenchymal lineage precursors, MSCs exhibit significant immune regulatory functions in vitro.
• Pre-clinical and early clinical studies indicate MSCs modulate immune responses, highlighting their central role.

Purpose of the Study:

• To review the immunological properties of Mesenchymal stromal cells (MSCs).
• To determine the precise position of MSCs within the immune system.
• To clarify whether MSCs are primarily immune cells or tissue precursors with immunomodulatory capabilities.

Main Methods:

• Comprehensive literature review of in vitro and in vivo studies on MSC immunology.
• Analysis of pre-clinical models demonstrating MSC efficacy in immunological disease.
• Evaluation of data from phase 1/2 clinical trials assessing MSC immune modulation.

Main Results:

• MSCs possess diverse and potent immune regulatory capacities.
• Evidence suggests MSCs play a central role in orchestrating immune responses.
• Clinical trials show signs of immune modulation following MSC infusion.

Conclusions:

• The immunomodulatory functions of MSCs challenge their traditional classification.
• Further research is needed to definitively categorize MSCs as immune cells or specialized precursor cells.
• A clear understanding of MSC immunological properties is essential for optimizing their clinical use in treating immune disorders.