Synoviocyte-targeted therapy synergizes with TNF inhibition in arthritis reversal


Svensson MND, Zoccheddu M, Yang S, Nygaard G, Secchi C, Doody KM, Slowikowski K, Mizoguchi F, Humby F, Hands R, Santelli E, Sacchetti C, Wakabayashi K, Wu DJ, Barback C, Ai R, Wang W, Sims GP, Mydel P, Kasama T, Boyle DL, Galimi F, Vera D, Tremblay ML, Raychaudhuri S, Brenner MB, Firestein GS, Pitzalis C, Ekwall A-KH, Stanford SM, Bottini N. Synoviocyte-targeted therapy synergizes with TNF inhibition in arthritis reversal [Internet]. Science Advances 2020;6(26):eaba4353.


Fibroblast-like synoviocytes (FLS) are joint-lining cells that promote rheumatoid arthritis (RA) pathology. Current disease-modifying antirheumatic agents (DMARDs) operate through systemic immunosuppression. FLS-targeted approaches could potentially be combined with DMARDs to improve control of RA without increasing immunosuppression. Here, we assessed the potential of immunoglobulin-like domains 1 and 2 (Ig1&2), a decoy protein that activates the receptor tyrosine phosphatase sigma (PTPRS) on FLS, for RA therapy. We report that PTPRS expression is enriched in synovial lining RA FLS and that Ig1&2 reduces migration of RA but not osteoarthritis FLS. Administration of an Fc-fusion Ig1&2 attenuated arthritis in mice without affecting innate or adaptive immunity. Furthermore, PTPRS was down-regulated in FLS by tumor necrosis factor (TNF) via a phosphatidylinositol 3-kinase–mediated pathway, and TNF inhibition enhanced PTPRS expression in arthritic joints. Combination of ineffective doses of TNF inhibitor and Fc-Ig1&2 reversed arthritis in mice, providing an example of synergy between FLS-targeted and immunosuppressive DMARD therapies.