First Author | Weber C | Year | 2012 |
Journal | Immunology | Volume | 136 |
Issue | 1 | Pages | 64-77 |
PubMed ID | 22260507 | Mgi Jnum | J:184093 |
Mgi Id | MGI:5320247 | Doi | 10.1111/j.1365-2567.2012.03559.x |
Citation | Weber C, et al. (2012) Toll-like receptor (TLR) 3 immune modulation by unformulated small interfering RNA or DNA and the role of CD14 (in TLR-mediated effects). Immunology 136(1):64-77 |
abstractText | The Toll-like receptors (TLRs) 3, 7, 8 and 9 stimulate innate immune responses upon recognizing pathogen-derived nucleic acids. TLR3 is located on the cell surface and in cellular endosomes and recognizes double-stranded viral RNA or the synthetic mimic poly rI:rC. Recently, unformulated small interfering RNA (siRNA) has been reported as ligand for surface-expressed murine TLR3. Blockage of TLR3 is achieved by single-stranded DNA. We confirm and expand the observation that poly rI:rC-mediated TLR3 immune activation is blocked in a sequence-, length-, backbone- and CpG-dependent manner. However, human TLR3 is not activated by siRNA, which may be the result of differences in the amino acid composition of the TLR3 loop 1 of mice and humans. Although CD14 was previously described as a co-receptor for murine TLR3 and other nucleic acid-recognizing TLRs, human CD14 acts only as co-receptor to human TLR9, but not TLR3, TLR7 or TLR8. We show that CD14 up-regulates the TLR9 immune response of A, B and C-class oligodeoxynucleotides but down-regulates the phosphoro-diester version of B-class oligodeoxynucleotides. |