Mesenchymal stem cells inhibit Th17 cell differentiation by IL-10 secretion

Area of Science:

• Immunology
• Cell Biology
• Stem Cell Research

Background:

• Mesenchymal stem cells (MSCs) are known to modulate immune responses.
• The precise mechanisms by which MSCs regulate T helper 17 (Th17) cell differentiation remain unclear.
• Th17 cells play critical roles in autoimmune diseases and host defense.

Purpose of the Study:

• To elucidate the underlying mechanisms of MSCs' regulatory effect on Th17 cell differentiation.
• To investigate the role of specific cytokines and transcription factors in this interaction.

Main Methods:

• Co-culture of mouse bone marrow-derived MSCs with specific T cells (CD4(+)CD25(low)CD44(low)CD62L(high)).
• Analysis of Th17 cell proportion, cytokine secretion (e.g., IL-10), and transcription factor expression (e.g., Rorγt).
• Techniques included flow cytometry, ELISA, qRT-PCR, and Western blotting, alongside IL-10 neutralization and RNA interference.

Main Results:

• Bone marrow-derived MSCs significantly inhibited Th17 cell differentiation.
• This inhibition was mediated by the secretion of interleukin-10 (IL-10).
• IL-10 neutralization or knockdown restored Th17 cell differentiation, confirming IL-10's crucial role. IL-10 suppressed Rorγt expression via SOCS3/STAT5 and reduced STAT3 binding to the Rorγt promoter.

Conclusions:

• MSCs exert an inhibitory effect on Th17 cell differentiation.
• Increased IL-10 secretion by MSCs is identified as the key mechanism for this suppression.
• The findings highlight a novel pathway involving IL-10, SOCS3, STAT5, STAT3, and Rorγt in MSC-mediated immune regulation.