Date: Monday, November 6, 2017
Session Type: ACR Poster Session B
Session Time: 9:00AM-11:00AM
Dysregulated IL-23/IL-17 responses have been linked to a myriad of inflammatory diseases including psoriasis, psoriatic arthritis and other forms of spondyloarthritides (SpA). IL-23/IL-17 inflammation is controlled by RORγt, the key Thelper17 (Th17) cell transcriptional regulator. RORγt is also expressed by subsets of innate-like T cells, including invariant natural killer T (iNKT) and γδ-T cells, but how this contributes to inflammatory disorders such as SpA is still unclear.
Blood samples were obtained from 27 healthy control subjects and 33 patients with newly diagnosed SpA (following ASAS 2010 criteria). Synovial fluid (SF) was obtained from patients with an active knee synovitis and an indication for aspiration. Patients were treatment naïve or under treatment with a NSAID and/or DMARD (Methotrexate, Sulfasalazin), but naïve for treatment with biologicals at the time op sampling. PBMC and SFMC were isolated from patient samples and were directly analyzed by multi-color flow cytometry for analysis of iNKT cells (CD3+6B11+ TCRVβ11+), γδ-T cells (CD3+TCRγδ+) and CD161+ and CD161- conventional Tconv (T cells excluded from innate-like T cells). Rorc and Il-23r mRNA expression on specific T cell subsets was measured by means of PrimeFlow RNA Assays. Flow cytometric data were analysed by standard gating procedures using FlowJo software and further explored by FlowSOM, a novel method for computational multi-color flow cytometry. Furthermore, sorted γδ-T cells and iNKT cells were cultured in the presence of αGalCer (for iNKT) or aCD3/aCD28Ab (γδ-T cells) with addition of IL-23, IL-1β, TGFB1 and IL-2 (IL-23 cocktail) in the presence or absence of a RORγt inhibitor. Cytokine production of cells was determined by intracellular flow cytometric staining or in supernatants by multiplex protein assays (MSD). In addition, phenotypical analyses were done by qPCR with specific primers for IL-23R, IL-17A and F, IL-22 and RORC.
Here, we describe a unique population of RORγt+T-betloPLZF– iNKT and TCRγδ-hi T cells (γδ-T cells with a high expression of the γδTCR), present in healthy peripheral blood. iNKT and γδ-hi T cells showed marked IL-23 mediated Th17-like immune responses and are clearly enriched within inflamed joints. Interestingly, in depth metacluster analyses by FlowSOM iterations showed skewing of novel iNKT cell subsets, already detectable in the blood of SpA patients. RORγt blocked Th17 cell function and inhibited IL-17 production while surprisingly preserved IL-22 production by iNKT and γδ-T cells. Further FlowSOM analyses showed that RORγt inhibition impacts distinctive IL-17+ iNKT cell subsets while preserving IL-22 subsets.
Overall, these findings highlight a unique diversity of human RORγt+ innate-like T cells and underscore the potential of RORγt antagonism to modulate aberrant Type 17 responses.
To cite this abstract in AMA style:Venken K, Labadia M, Hoyt K, Wayne A, Hughes R, Turner M, Smith D, Harcken C, Decruy T, Wahle J, Wang CT, Jacques P, Van Gassen S, Varkas G, Cypers H, van Den Bosch F, Saeys Y, Nabozny G, Elewaut D. RORγt Inhibition Selectively Targets Pathogenic Subsets of Human iNKT and γδ-T Cells Enriched in Spondyloarthritis While Preserving Tissue Protective IL-22 Responses [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/ror%ce%b3t-inhibition-selectively-targets-pathogenic-subsets-of-human-inkt-and-%ce%b3%ce%b4-t-cells-enriched-in-spondyloarthritis-while-preserving-tissue-protective-il-22-responses/. Accessed September 24, 2021.
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