Seoul National University Gangbuk-gu, Seoul, South Korea
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Hee Sung Kwon1, Mi Hyeon Kim2, Jeoung Yeon Kim2, Seon Uk Kim2, Hae Rim Kang1, Seo Yoon Ban3, Gyong Sik Ha4, Chung Min Lee4, Jeong Seok Lee5 and Eun Young Lee2, 1Interdisciplinary Program in Cancer Biology, Integrated Major in Innovative Medical Science, Seoul National University, Seoul, South Korea, 2Seoul National University College of Medicine, Seoul, South Korea, 3Department of Cancer biology, Graduate School of College of Medicine, Seoul National University, Seoul, South Korea, 4Research institute, IMBiologics Corp, Suwon, South Korea, 5Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Seoul, South Korea
Background/Purpose: Rheumatoid arthritis (RA) is a chronic, inflammatory disease that leads to progressive cartilage and bone destruction. TNF superfamily member OX40 ligand (OX40L; CD252) is expressed specifically to synovial tissue and OX40/OX40L interaction is contributed to the development of T-cell mediated immunity in RA. In collagen-induced arthritis mouse model, it was demonstrated that blockade of TNF-α or OX40L significantly ameliorated disease activity. We present targeting both TNF-α and OX40L is superior to single treatment in fibroblast-like synoviocytes (FLS) invasiveness and osteoclast activation which are crucial RA pathology.
Methods: RA FLS were used from passage 4-6. FLS were stimulated with TNF-α (10ng/ml) for 2h and then treated with single TNF-α inhibitor (50nM), OX40L inhibitor (50nM) or IMB-101, a TNF-α/OX40L bispecific antibody (50nM) for 24hrs. Differential expression of RA FLS genes were analyzed by RT-PCR. For osteoclast differentiation assay, FLS were stimulated with TNF-α (10ng/ml) for 3 days, after which CD14+ monocytes were co-cultured with the IMB-101 (50nM) in the presence of M-CSF (20ng/ml) for 3 weeks. Osteoclasts were evaluated by tartrate-resistant acid phosphatase (TRAP) staining.
Results: OX40L was increased in TNF- α induced RA FLS compared to unstimulated RA FLS (p< 0.05) (n=7). RT-PCR analysis revealed significant reduction of IL-6, IL-1β, CCL2, CX3CL1, MMP-1, MMP-3, ICAM-1, RANKL, VEGF and HIF1-α in TNF-α stimulated RA FLS after IMB-101 or anti TNF treatment (n=4). Among these genes, MMP-3, RANKL and VEGF were significantly reduced in dual inhibition of TNF-α and OX40L than single target therapies. In co-culture system of RA FLS and CD14+ monocytes for osteoclast formation, IMB-101 decrease the number of TRAP-positive multinucleated cells over TNF-α inhibitor.
Conclusion: These results indicated that dual inhibition of TNF-α and OX40L axis simultaneously are associated with reduction of invasiveness in synovial fibroblast and joint destruction in RA.
H. Kwon: None; M. Kim: None; J. Kim: None; S. Kim: None; H. Kang: None; S. Ban: None; G. Ha: None; C. Lee: None; J. Lee: None; E. Lee: None.
