Toll-like receptors direct antimicrobial immune responses— and driving arthritis?

Toll-like receptors as targets for immune disorders

Since the identification of the first Toll-like receptor (TLR) in humans in 1997, understanding of the molecular basis for innate immunity has increased significantly. The TLR family and downstream signalling pathways have been extensively characterised, There is now significant evidence suggesting a role for TLRs in human inflammatory and immune diseases such as rheumatoid arthritis, diabetes, allergy/asthma and atherosclerosis. Various approaches have been taken to identify novel therapeutic agents targeting TLRs including biologics, small molecules and nucleic acid-based drugs. Several are now being evaluated in the clinic and showing promise against various diseases. This review paper outlines the recent advances in the understanding of TLR biology and highlights novel TLR agonists and antagonists in development for the treatment of immune diseases.

The fibroblast-like synovial cell in rheumatoid arthritis: a key player in inflammation and joint destruction

Although multiple cell types are present in the rheumatoid joint, the fibroblast-like synovial cell (FLS) is among the most prominent. It is now appreciated that the FLS is not only space-filling, but is directly responsible for cartilage destruction, and also drives both inflammation and autoimmunity. In this article, we consider the normal role of the FLS in healthy joints, and review evidence that implicates the FLS as a central player in the propagation of rheumatoid arthritis.