J Rheumatol 2021 Aug 1. Epub 2021 Aug 1.
Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA, Product and Process Development, Allogene Therapeutics, San Francisco, CA, Seattle Children's Research Institute, Seattle, WA, Division of Rheumatology, Department of Pediatrics, University of Washington, Seattle WA, Janssen Research & Development, LLC, PA. Sources of support: This work was supported by National Institutes of Health [R01 AR074939, R21 AR075134, and R21 AR077266 to TM and T32 AR007108 to KCU]; and by Lupus Research Alliance [grant number 519414 to CL]. Conflict of interest: TM has received consulting and advisory board fees from Glysantis, Kiniksa, Cugene, QiLu, and Miro Bio. MAB is an employee of Allogene Therapeutics and AS in an employee of Janssen Research & Development. Address correspondence to: Tomas Mustelin, Division of Rheumatology, Department of Medicine, University of Washington, 750 Republican Street, Room E507, Seattle, WA98109, phone (206) 616-6130, E-mail:
Objective: Autoantibodies against proteins encoded by human endogenous retrovirus K (HERV-K) have been reported in patients with rheumatoid arthritis (RA), but their relevance, if any, has remained unresolved. We revisited this question and tested if such autoantibodies may react with citrullinated epitopes on the envelope (Env) protein of HERV-K.
Methods: Immunoblotting and ELISAs were conducted with unmodified Env protein and with Env citrullinated by protein arginine deiminase (PAD) 4. Read More