AUTHOR=van der Meer Rienk Gerben , Spoorenberg Anneke , Brouwer Elisabeth , Doornbos-van der Meer Berber , Boots Annemieke M. H. , Arends Suzanne , Abdulahad Wayel H. 

TITLE=Mucosal-associated invariant T cells in patients with axial spondyloarthritis

JOURNAL=Frontiers in Immunology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2023.1128270

DOI=10.3389/fimmu.2023.1128270

ISSN=1664-3224

ABSTRACT=<sec><title>Background</title><p>Several studies implicate Th17-cells and its cytokine (IL-17) in disease pathogenesis of spondyloarthritis (SpA), with available evidence supporting a pathogenic role of CD8+ T-cells. However, data on the involvement of CD8+ mucosal-associated invariant T-cells (MAIT) and their phenotypic characterization and inflammatory function including IL-17 and Granzyme A production in a homogenous population of SpA-patients with primarily axial disease (axSpA) are lacking.</p></sec><sec><title>Objectives</title><p>Quantify and characterize the phenotype and function of circulating CD8+MAIT-cells in axSpA-patients with primarily axial disease.</p></sec><sec><title>Methods</title><p>Blood samples were obtained from 41 axSpA-patients and 30 age- and sex-matched healthy controls (HC). Numbers and percentages of MAIT-cells (defined as CD3<sup>+</sup>CD8<sup>+</sup>CD161<sup>high</sup>TCR<sub>Vα7.2</sub><sup>+</sup>) were determined, and production of IL-17 and Granzyme A (GrzA) by MAIT-cells were examined by flow cytometry upon <italic>in vitro</italic> stimulation. Serum IgG specific for CMV was measured by ELISA.</p></sec><sec><title>Results</title><p>No significant differences in numbers and percentages of circulating MAIT-cells were found between axSpA-patients and HCr zijn meer resultaten de centrale memory CD8 T cellen. cellen van patirculating MAIT cells.. Further phenotypic analysis revealed a significant decrease in numbers of central memory MAIT-cells of axSpA-patients compared to HC. The decrease in central memory MAIT-cells in axSpA patients was not attributed to an alteration in CD8 T-cell numbers, but correlated inversely with serum CMV-IgG titers. Production of IL-17 by MAIT-cells was comparable between axSpA-patients and HC, whereas a significant decrease in the production of GrzA by MAIT-cells from axSpA-patients was observed.</p></sec><sec><title>Conclusions</title><p>The decrease in cytotoxic capability of circulating MAIT-cells in axSpA-patients might implicate that these cell types migrate to the inflamed tissue and therefore associate with the axial disease pathogenesis.</p></sec>