Related Experiment Videos
U1 RNA induces innate immunity signaling
Robert W Hoffman1, Tal Gazitt, Mark F Foecking
1University of Miami and the Miami VA Medical Center, Miami, Florida 33136, USA.
Arthritis and Rheumatism
|October 1, 2004
Summary
U1 RNA, a component of the U1-70-kd RNP complex, can activate Toll-like receptor 3 (TLR-3), suggesting it may contribute to autoimmunity in connective tissue diseases by stimulating innate immunity.
Area of Science:
- Immunology
- Molecular Biology
- Autoimmunity
Background:
- The U1-70-kd RNP is a key autoantigen in connective tissue diseases.
- The role of endogenous U1 RNA in immune signaling and immunogenicity is not well understood.
Purpose of the Study:
- To investigate if U1 RNA acts as a pro-immune signal.
- To determine if U1 RNA is immunogenic and can activate innate immune pathways.
Main Methods:
- Assayed splenocyte proliferation in response to U1 RNA in control and MyD88-knockout cells.
- Measured IL-6 and IL-8 secretion induced by U1 RNA in a human cell line expressing TLR-3 and TLR-5.
Main Results:
- U1 RNA induced splenocyte proliferation and IL-6/IL-8 secretion, similar to the TLR-3 agonist poly(I-C).
- RNase digestion abolished U1 RNA's ability to induce proliferation and cytokine secretion.
- MyD88-knockout cells showed attenuated proliferation in response to U1 RNA.
Conclusions:
- U1 RNA activates TLR-3, indicating it can induce innate immune responses.
- The double-stranded secondary structure of U1 RNA contributes to its TLR-3 activation.
- U1 RNA's immunogenicity may explain autoimmunity targeting RNA-binding proteins.