AUTHOR=Mohr Audrey , Trésallet Christophe , Monot Natacha , Bauvois Adeline , Abiven Delphine , Atif Muhammad , Claër Laetitia , Malhotra Rajneesh , Mayer Gaëll , Balderas Robert , Vaarala Outi , Deniziaut Gabrielle , Brocheriou Isabelle , Buffet Camille , Leenhardt Laurence , Gorochov Guy , Miyara Makoto 

TITLE=Tissue Infiltrating LTi—Like Group 3 Innate Lymphoid Cells and T Follicular Helper Cells in Graves' and Hashimoto's Thyroiditis

JOURNAL=Frontiers in Immunology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2020.00601

DOI=10.3389/fimmu.2020.00601

ISSN=1664-3224

ABSTRACT=<p><bold>Background:</bold> Hashimoto's thyroiditis (HT) and Graves' disease (GD) are autoimmune thyroid disorders (AITDs). These conditions have been associated to abnormalities in circulating regulatory T cells (Tregs). We postulated that immune perturbations could be more pronounced at the thyroid tissue level.</p><p><bold>Methods:</bold> The phenotype of PBMCs and immune cells infiltrating thyroid tissue from 19 patients with HT, 21 patients with GD, and 30 controls has been analyzed by flow cytometry.</p><p><bold>Results:</bold> We report that blood and thyroid Treg cell subsets are similarly represented in all AITDs patients and controls. Increased Lymphoid tissue inducer (LTi)-like ILC3 and CXCR5<sup>+</sup> PD-1<sup>hi</sup> CD4<sup>+</sup> T follicular helper cells (Tfh) tissue-infiltrating cells, together with the prevalence of tertiary lymphoid structures (TLS) and germinal centers (GCs) represented a typical immune signature in all HT and 60% of GD patients. In the remaining group of GD patients, the absence of the aforementioned abnormalities was associated with a higher prevalence of ophthalmopathy.</p><p><bold>Conclusion:</bold> Tissue infiltrating Lymphoid Tissue inducer—like group 3 Innate Lymphoid cells and T follicular helper cells are increased in most thyroid autoimmune disease.</p>