Differentiation of follicular helper T cells by salivary gland epithelial cells in primary Sjogren's syndrome.
Fiche publication
Date publication
juin 2014
Auteurs
Membres identifiés du Cancéropôle Est :
Pr BAHRAM Siamak, Pr GOTTENBERG Jacques-Eric
Tous les auteurs :
Gong YZ, Nititham J, Taylor K, Miceli-Richard C, Sordet C, Wachsmann D, Bahram S, Georgel P, Criswell LA, Sibilia J, Mariette X, Alsaleh G, Gottenberg JE
Lien Pubmed
Résumé
Follicular helper T cells (Tfh), which play a pivotal role in B cell activation and differentiation in lymphoid structures, secrete IL-21 whose augmented secretion is a hallmark of several autoimmune diseases. To decipher the cellular and molecular interactions occurring in salivary glands of patients suffering from primary Sjogren's syndrome (pSS), we investigated whether salivary gland epithelial cells (SGECs) were capable to induce Tfh differentiation. Co-cultures of naive CD4(+) T cells and SGECs from both patients with pSS and controls were performed. Here, we report that IL-6 and ICOSL expression by SGECs contributes to naive CD4(+) T differentiation into Tfh cells, as evidenced by their acquisition of a specific phenotype, characterized by Bcl-6, ICOS and CXCR5 expression and IL-21 secretion, but also but by their main functional feature: the capacity to enhance B lymphocytes survival. We demonstrated an increase of serum IL-21 with systemic activity. Finally, we analyzed the potential occurrence of a genetic association between IL-21 or IL-21R gene polymorphisms and pSS or elevated IL-21 secretion. This study, which demonstrates a direct induction of Tfh differentiation by SGECs, emphasizes a yet unknown pathogenic role of SGECs and suggests that Tfh and IL-21 might be relevant biomarkers and/or therapeutic targets in primary Sjogren's syndrome.
Référence
J Autoimmun. 2014 Jun;51:57-66