Citrullinated human fibrinogen triggers arthritis through an inflammatory response mediated by IL-23/IL-17 immune axis

• DOI: 10.1016/j.intimp.2021.108363
• Publication Date: 2021-11-20T00:15:33Z
• Authors: André Lopes Saraiva; Raphael Sanches P...; Flávio Protasio V...; Jhimmy Talbot; Kalil Alves de Lima; João Paulo Mesqui...; Thiago Mattar Cunha; Paulo Louzada-Junior; Fernando Queiroz ...; José Carlos Alves...
• Keywords: Immunogen; Inflammatory arthritis; Interleukin-23; Pathogenesis

Rheumatoid arthritis (RA) is an autoimmune disease that causes joint destruction. Although its etiology remains unknown, citrullinated proteins have been considered as an auto-antigen able to trigger an inflammatory response in RA. Herein, we modified the classical antigen-induced arthritis (AIA) model by using citrullinated human plasma fibrinogen (hFIB) as an immunogen to investigate the mechanism of inflammation-driven joint damage by citrullinated hFIB in C57BL/6 mice. We found that hFIB-immunized mice showed high serum levels of anti-citrullinated peptides antibodies (ACPAs). Moreover, hFIB immunized mice showed increased mechanical hyperalgesia, massive leukocyte infiltration, high levels of inflammatory mediators, and progressive joint damage after the intra-articular challenge with citrullinated hFIB. Interestingly, hFIB-induced arthritis was dependent on IL-23/IL-17 immune axis-mediated inflammatory responses since leukocyte infiltration and mechanical hyperalgesia were abrogated in Il17ra-/- and Il23a-/- mice. Thus, we have characterized a novel model of experimental arthritis suitable to investigate the contribution of ACPAs and Th17 cell-mediated immune response in the pathogenesis of RA.