Antibody response to homologous epitopes of Epstein-Barr virus, Mycobacterium avium subsp. paratuberculosis and IRF5 in patients with different connective tissue diseases and in mouse model of antigen-induced arthritis
Marco Bo, Magdalena Niegowska, Hayley L. Eames, Hannah Almuttaqi, Giannina Arru, Gian Luca Erre, Giuseppe Passiu, Tariq Khoyratty, Erinke van Grinsven, Irina A. Udalova, Leonardo A. Sechi
Abstract
BACKGROUND: (MAP). Antigen-induced arthritis (AIA) experiments have been performed in control and IRF5 conditional knockout mice to reinforce the hypothesis that antibodies generated against the three homologous peptides are cross-reactive. METHODS: ) peptides were tested by indirect ELISA in sera from 100 RA patients, 54 patients with other CTDs (14 SLE, 28 SSc and 12 SSj) and 100 healthy subjects (HCs). Antibody responses to the same wt peptides have been tested in AIA mouse sera after immunization with complete Freud's adjuvant (CFA) and methylated bovine serum albumin (mBSA) to induce arthritis in the knee joint. RESULTS: Our results show differential antibody responses to BOLF1, MAP_4027 and IRF5 peptides among CTDs, highlighting their potential as diagnostic biomarkers in these diseases. Experiments performed in IRF5 conditional knockout mice support the hypothesis of cross-reactivity between the investigated homologous antigens.