Expression of nucleic acid binding Toll-like receptors in control, lupus and transplanted kidneys - a preliminary pilot study.

We hypothesized that nucleic acids, free and/or complexed, filtered and/or locally released, might be entrapped in the kidneys because of the specific nucleic acid binding microbial pattern recognizing Toll-like receptors (TLRs). This hypothesis of nucleic acid binding potential was tested using paraffin sections from healthy control, SLE and transplant kidneys, which were labelled using TLR-specific rabbit or goat anti-human antibodies in immunoperoxidase staining. Normal and transplant kidneys contain some double- (TLR-3) and single-stranded RNA binding (TLR-8) receptors, but in particular double-stranded RNA binding receptor TLR-7, mostly in tubuli, whereas no DNA binding TLR-9 was found. SLE kidneys contain more TLR-3 and TLR-8 and express de novo also TLR-9, in particular in glomeruli. On the contrary, TLR-7 was relatively weak in SLE. It is concluded that kidneys have a capacity to bind nucleic acids. TLR stimulation leads to the production of tumour necrosis factor-a and other pro-inflammatory cytokines and to up-regulation of co-stimulatory molecules necessary for the adaptive immune response. This makes renal tissues a potential target for inflammatory and immune responses in autoimmune disease and in the reaction for the foreign tissue. [ABSTRACT FROM AUTHOR]

Copyright of Lupus is the property of Sage Publications Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)