OP0027 AS-RELATED TCR BETA CLONOTYPES ARE PRESENT IN DIFFERENT INFLAMED TISSUES OF PATIENTS WITH SPONDYLOARTHROPATHIES
Authors: E. Komech, A. Barinova, E. Shmidt, T. Korotaeva, A. Koltakova, N. Nikitina, E. Belousova, M. Shapina, S. Rodionovskaya, I. Nikishina, S. Vahlyarskaya, D. Atarshchikov, E. Klescheva, D. Chudakov, S. Lukyanov, I. Zvyagin
Journal: Annals of the Rheumatic Diseases (2021)

Background: Recently a group of T-cell clones with characteristic T-cell receptor (TCR) motif was identified in peripheral blood and synovial fluid of HLA-B*27+ patients with ankylosing spondylitis (AS) [1-2] - a prototypic disease from a wider group of spondyloarthropathies (SpAs). Extraarticular manifestations of AS could involve skin, intestine or eye. Emerging data indicate linkage between intestinal and joint inflammation, including expression of gut-associated integrins on synovial T-cells [3-4]. However, clonal T-cell composition and presence of identical clones in different inflamed sites in SpAs remains poorly studied. Objectives: To investigate clonal T-cell repertoire and presence of AS-related TCR motif in different sites of inflammation of patients with SpA. Methods: Samples of synovial fluid (SF) were obtained from HLA-B*27+ and HLA-B*27- patients with ankylosing spondylitis (AS) and psoriatic arthritis (PsA), as well as gut biopsy samples from patients with AS and Crohn’s disease (AS/CD) or ulcerative colitis (AS/UC), and conjunctival swabs from patients with uveitis (Uv) and with or without articular manifestations (Table 1). Also SF and gut biopsy samples were obtained from HLA-B*27+ patients with juvenile idiopathic arthritis (JIA). For one patient PsA patient paired samples of SF and gut biopsy were obtained. Table 1. Detection of the AS-related motif TRBV9_CASS[V/A/L/P][G/A] [L/T/V][F/Y]STDTQYF_TRBJ2-3 in bTCR repertoires of samples from different inflamed sites of patients with SpA Tissue Diagnosis B27+ B27 - AS-related TCR motif+ among all samples from B27+ donors Synovial fluid AS 20 12 PsA JIA Intestinal biopsy AS/CD 4 3 3 / 4 AS/UC JLA Conjunctival swab Uv 8 0 4 / 8 SF and gut samples were processed to isolate mononuclear cells, while conjunctival swabs were directly lysed in the lysis buffer. CD3+ β7-intergin+ cells were isolated from SF by fluorescence-activated cell sorting. Deep TCR repertoire profiling was carried out using UMI-based cDNA library preparation technology [1]. Results: Identical T-cell clonotypes were detected between paired SF and gut samples of the same patient with psoriatic arthritis and intestinal inflammation. The subpopulation of β7-intergin+ SF T-cells shared significantly more identical clonotypes with gut biopsy repertoire compared to the bulk SF T-cell repertoire. Clonotypes belonging to the AS-related TCR beta motif TRBV9_CASS[V/A/L/P][G/A][L/T/V][F/Y]STDTQYF_TRBJ2-3 were detected in all inflamed tissues tested: synovial fluid, intestinal biopsies and conjunctival swabs of SpA patients (Table 1). Importantly, we observed these clonotypes exclusively in samples from HLA-B*27+ donors (n=26), but not in HLA-B27- context (n=15) with comparable analysis depth, thus confirming strong HLA-B*27-restriction of the clonotypes. The AS-related clonotypes were detected in the subpopulation of β7-intergin+ SF T-cells from HLA-B*27+ patients with PsA. Conclusion: For the first time we directly report the T-cell clonal sharing between synovial fluid and inflamed gut tissue of SpA patients. In sum our data suggests involvement of identical T-cell clones in inflammation in different anatomical sites in SpA. References: [1]Komech et al. Rheumatology (Oxford). 2018;57(6):1097-1104. [2]Faham et al. Arthritis Rheumatol. 2016;11(10):300-308. [3]Guggino et al. Ann Rheum Dis . Published Online First: 18 October 2019.doi:10.1136/annrheumdis-2019-216456. [4]Qaiyum et al Ann Rheum Dis . 2019;78(11):1566-1575. Acknowledgements: We thanks all the patients and medical personnel involved in the study Disclosure of Interests: None declared