Soluble CD14 in synovial fluid from patients with OA and meniscal injury modulates the response of synovial fibroblasts to LPS

摘要: Background and objectives It has been hypothesised that inflammation is triggered in the osteoarthritic (OA) joint via stimulation of pattern-recognition receptors such as toll-like (TLRs) by products tissue degradation. We tested whether a TLR-4 stimulating factor was present synovial fluid (SF) from patients with meniscal injury or without OA. Materials methods SF obtained undergoing arthroscopic surgery for tears, concomitant OA, lipopolysaccharide (LPS) contamination using LAL assay (Pierce Chemicals). HEK293 cells transfected either TLR-4, + MD2, were used to screen ability induce IL-8 production. Synoviocyte cell lines established post-mortem donors, between passages 4 8. Synoviocytes stimulated stimulus (ultrapure LPS 100 ng/ml, Invivogen Inc.), alone, 6 18 h. culture supernatants measured ELISA. In blocking experiments, pre-incubated anti-CD14 (clone MEM-18), immunoadsorbed bound protein-G coupled beads, prior stimuli. sCD14 levels SFs Results Only 2 17 production HEK transfectants. Moreover, inhibited assay. Therefore, we would inhibit synoviocytes response ligand (LPS). Instead, addition (0.09–25%) resulted significant augmentation (> fold) synoviocytes. CD14, cofactor responses LPS, expressed on cell-surface soluble mediator (sCD14). As did not express surface CD14 flow cytometry, found at 1- microgram/ml. Removal protein G preincubation anti-CD14, abolished augment LPS. Conclusions vitro, augments This effect appeared be largely due sCD14. are expected contact vivo, these results suggests setting OA can sensitise respond inflammatory stimuli ligands. various arthritic states, other TLRs, currently being explored.