... characterized by < /b> in< /b> ltration of in< /b> ammatory cells < /b> into the joints, leadingto the proliferation of fibroblast-like synoviocytes (FLS) and < /b> the destruction of cartilage and < /b> bone. In < /b> RA syno-vial tissue, ... ofcartilage and < /b> bone. In < /b> RA synovial tissue, the in< /b> ltrating cells < /b> such asmacrophages, T cells,< /b> B cells < /b> and < /b> dendritic cells < /b> play important role in < /b> thepathogenesis of RA. Migration of leukocytes into ... IL- 1b, TNF-a and< /b> IFN-c. (B) Chemokines expressed in < /b> the joint recruit leukocytes intothe joints. In < /b> addition to functioning in < /b> cell trafficking, severalchemokines have other biological abilities....