Session Type: Abstract Submissions (ACR)
The presence of anti-citrullinated proteins antibodies (ACPAs) in RA is associated with aggressive disease phenotype and bone destruction. As synovial fibroblasts (SFs) are considered key players of both synovial inflammation and bone destruction in rheumatoid arthritis (RA), we studied the effect of ACPAs on fibroblasts migration.
Human dermal fibroblasts (HDFs) were obtained from PromoCell. SFs were isolated from synovial tissue of RA patients (RASFs) by enzymatic digestion. ACPA positive and negative IgGs were separated from plasma of RA patients and monoclonal anti-citrullinated antibodies were generated from RA synovial fluid by single B-cells1. Migration scratch assays were performed using either RASFs or HDFs to test the effect of ACPAs, anti-citrullinated monoclonal antibodies and appropriate negative controls. The effect of a phosphatidyl inositol-3-kinase (PI3K) inhibitor (wortmannin) and a focal adhesion kinase (FAK) inhibitor (PF-573228) was tested. Light microscopy images were taken at baseline and after 6 hours incubation and analyzed using NIH ImageJ to calculate migration index. Cytotoxicity and proliferation assays were done in parallel with migration assays.
ACPAs but not control IgGs induced a 3.9±0.5 (mean±SD) fold increase in HDFs and a 2.6±0.5 (mean±SD) fold increase in RASFs migration (p<0.05). PI3K but not FAK inhibition almost completely abolished ACPAs effects, with minimal fold migration increase of 1.4±0.4 (mean±SD). No difference in either cytotoxicity or proliferation rate were observed between different treatments. One out of three different anti-citrullinated monoclonal antibodies displayed similar mig
We describe a novel effect of ACPAs, providing a link between synovial fibroblasts and the adaptive immune system. We further suggest that different fine specificities of ACPAs might have distinct impact on disease pathogenesis.
1. Amara, K. et al. Monoclonal IgG antibodies generated from joint-derived B cells of RA patients have a strong bias toward citrullinated autoantigen recognition. J Exp Med 210, 445-55 (2013).
A. H. Hensvold,
S. B. Catrina,
A. I. Catrina,
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/anti-citrullinated-proteins-antibodies-promote-synovial-fibroblast-migration-in-rheumatoid-arthritis/