Fractalkine is a unique C-X3-C motif chemokine expressed on activated endothelial cells. CX3CR1, a unique fractalkine receptor, is expressed on subsets of T cells, monocytes, and NK cells. In synovial tissue in rheumatoid arthritis (RA), fractalkine was expressed on endothelial cells and fibroblast-like synoviocytes. CX3CR1 was expressed on cells that infiltrated RA synovial tissue. An anti-fractalkine monoclonal antibody (mAb) inhibited arthritis in a murine model by blocking cellular infiltration into synovial tissue. In clinical trials, anti-fractalkine mAb attenuated arthritis of RA. Fractalkine promotes inflammatory cell infiltration into RA synovial tissue; thus, it has potential as a therapeutic target for RA.
Toshihiro Nanki (Sun,) studied this question.