Functional Roles of Pattern Recognition Receptors That Recognize Virus Nucleic Acids in Human Adipose-Derived...

Area of Science:

• Immunology
• Cell Biology
• Virology

Background:

• Human adipose-derived mesenchymal stem cells (hAD-MSCs) modulate immune responses.
• Increasing evidence suggests hAD-MSCs mediate innate immunity via pattern recognition receptors (PRRs).
• The role of PRRs in sensing viral nucleic acids in hAD-MSCs remains unexplored.

Purpose of the Study:

• Investigate the expression and function of PRRs recognizing viral RNA and DNA in hAD-MSCs.
• Determine if these PRRs mediate antiviral responses in hAD-MSCs.

Main Methods:

• Assessed expression of Toll-like receptor 3 (TLR3), retinoic acid-inducible gene I (RIG-I), and gamma-interferon inducible protein 16 (IFI16) in hAD-MSCs.
• Stimulated hAD-MSCs with poly(I:C) (synthetic viral RNA analog) and HSV60 (synthetic viral DNA analog).
• Utilized gene knockdown techniques for TLR3, RIG-I, and IFI16 to assess their roles in antiviral responses.

Main Results:

• hAD-MSCs express TLR3, RIG-I, and IFI16, which recognize viral RNA and DNA.
• Poly(I:C) and HSV60 activated TLR3/RIG-I and IFI16, respectively, inducing type I interferons (IFN-α/β) and antiviral proteins.
• Knockdown of TLR3, RIG-I, or IFI16 attenuated these antiviral responses.
• Both stimuli induced IFN-α/β via IFN-regulatory factor 3 phosphorylation.

Conclusions:

• PRRs recognizing viral nucleic acids are expressed in hAD-MSCs.
• These PRRs are functional and mediate antiviral responses in hAD-MSCs.
• hAD-MSCs possess an innate immune sensing capability against viral nucleic acids through PRRs.