| dc.description.abstract | The autoimmune polyendocrine syndrome type 1 (APS1) is a complex and rare monogenic form of autoimmunity caused by pathogenic variants of the autoimmune regulator (AIRE) gene; a transcription factor primarily expressed in the thymus and crucial for central immune tolerance. As a consequence, these patients display a wide variety of autoimmune manifestations in endocrine organs. The identification of the origin and major immune cell lineages involved in the development and pathogenesis of APS-1, remains an emergent issue due to sparse knowledge. In this work, a detailed immunological characterization and identification of specific immune subsets using functional lineage markers was performed by mass cytometry (CYTOF, cytometry by time-of-flight) using fixed blood from a cohort of 6 APS-1 patients and corresponding sex- and age-matched healthy controls. The results from this high dimensional CyTOF data showed no large alterations in the positive target populations but revealed a relative reduction in the frequency of CD45+ CD3+ CD14- CD19- CD56+ NKT cells compared to controls (mean APS-1= 4.901%; mean healthy controls= 11.35%, p= 0.00433). Furthermore, a flow cytometry panel was successfully generated and optimised for T cell transcription factors to phenotypically characterize T cell subpopulations in peripheral blood mononuclear cells (PBMC) from 5 APS-1 patients from our study cohort, as well as healthy controls. High expressions of Eomes were detected in unstimulated PBMCs of APS-1 patients compared to healthy controls. However, expressions from T cell subgroups, CXCR3+, GATA3+, RORgt+, T.BET, FOXP3+ cells did not reach significance. We succeeded in generating Th2- and Th17-polarised cells with their signature cytokines, IL-5, and IL-17 respectively, in a small cohort of APS-I patients. A relative proliferation of RORgt+, GATA3+ and FOXP3+ cells were observed with no major discrepancies compared to healthy controls. In addition, the response of some of the T cell subsets measured by both flow and mass cytometry were comparable and no large variations were detected. This could further indicate that CyTOF analysis with fixed blood and flowcytometry analysis of PBMCs are reliable to reproducibly measure immune subsets in APS-1 patients. Thus, even though with limited number of patients, our study might enhance and contribute to a better understanding of immune cell responses in AIRE- deficient patients. In depth knowledge about immune cell compositions is important to illuminate disease pathogenesis, predict subsequent diagnosis, improve outcome, and develop new therapies | |
