Serr Isabelle, Fürst Rainer W, Ott Verena B, Scherm Martin G, Nikolaev Alexei, Gökmen Füsun, Kälin Stefanie, Zillmer Stephanie, Bunk Melanie, Weigmann Benno, Kunschke Nicole, Loretz Brigitta, Lehr Claus-Michael, Kirchner Benedikt, Haase Bettina, Pfaffl Michael, Waisman Ari, Willis Richard A, Ziegler Anette-G, Daniel Carolin
Institute for Diabetes Research, Independent Young Investigator Group Immune Tolerance in Type 1 Diabetes, Helmholtz Diabetes Center at Helmholtz Zentrum München, 80939 Munich, Germany; Deutsches Zentrum für Diabetesforschung, 85764 Munich, Germany.
Deutsches Zentrum für Diabetesforschung, 85764 Munich, Germany; Institute for Diabetes Research, Helmholtz Diabetes Center at Helmholtz Zentrum München, 80939 Munich, Germany; Klinikum rechts der Isar, Technische Universität München, 80939 Munich, Germany.
Proc Natl Acad Sci U S A. 2016 Oct 25;113(43):E6659-E6668. doi: 10.1073/pnas.1606646113. Epub 2016 Oct 10.
Aberrant immune activation mediated by T effector cell populations is pivotal in the onset of autoimmunity in type 1 diabetes (T1D). T follicular helper (TFH) cells are essential in the induction of high-affinity antibodies, and their precursor memory compartment circulates in the blood. The role of TFH precursors in the onset of islet autoimmunity and signaling pathways regulating their differentiation is incompletely understood. Here, we provide direct evidence that during onset of islet autoimmunity, the insulin-specific target T-cell population is enriched with a C-X-C chemokine receptor type 5 (CXCR5)CD4 TFH precursor phenotype. During onset of islet autoimmunity, the frequency of TFH precursors was controlled by high expression of microRNA92a (miRNA92a). miRNA92a-mediated TFH precursor induction was regulated by phosphatase and tension homolog (PTEN) - phosphoinositol-3-kinase (PI3K) signaling involving PTEN and forkhead box protein O1 (Foxo1), supporting autoantibody generation and triggering the onset of islet autoimmunity. Moreover, we identify Krueppel-like factor 2 (KLF2) as a target of miRNA92a in regulating human TFH precursor induction. Importantly, a miRNA92a antagomir completely blocked induction of human TFH precursors in vitro. More importantly, in vivo application of a miRNA92a antagomir to nonobese diabetic (NOD) mice with ongoing islet autoimmunity resulted in a significant reduction of TFH precursors in peripheral blood and pancreatic lymph nodes. Moreover, miRNA92a antagomir application reduced immune infiltration and activation in pancreata of NOD mice as well as humanized NOD Scid IL2 receptor gamma chain knockout (NSG) human leucocyte antigen (HLA)-DQ8 transgenic animals. We therefore propose that miRNA92a and the PTEN-PI3K-KLF2 signaling network could function as targets for innovative precision medicines to reduce T1D islet autoimmunity.
由效应T细胞群体介导的异常免疫激活在1型糖尿病（T1D）自身免疫的发病机制中起关键作用。滤泡辅助性T（TFH）细胞在诱导高亲和力抗体方面至关重要，其前体记忆区在血液中循环。TFH前体在胰岛自身免疫发病机制中的作用以及调节其分化的信号通路尚未完全明确。在此，我们提供直接证据表明，在胰岛自身免疫发病过程中，胰岛素特异性靶向T细胞群体富含C-X-C趋化因子受体5（CXCR5）+CD4+ TFH前体表型。在胰岛自身免疫发病过程中，TFH前体的频率受微小RNA92a（miRNA92a）高表达的控制。miRNA92a介导的TFH前体诱导受磷酸酶和张力蛋白同源物（PTEN）-磷脂酰肌醇-3-激酶（PI3K）信号通路调控，该信号通路涉及PTEN和叉头框蛋白O1（Foxo1），支持自身抗体产生并引发胰岛自身免疫的发病。此外，我们确定Krüppel样因子2（KLF2）是miRNA92a在调节人TFH前体诱导中的一个靶点。重要的是，miRNA92a拮抗剂在体外完全阻断了人TFH前体的诱导。更重要的是，将miRNA92a拮抗剂体内应用于正在发生胰岛自身免疫的非肥胖糖尿病（NOD）小鼠，导致外周血和胰腺淋巴结中TFH前体显著减少。此外，应用miRNA92a拮抗剂可减少NOD小鼠以及人源化NOD Scid白细胞介素2受体γ链敲除（NSG）人白细胞抗原（HLA）-DQ8转基因动物胰腺中的免疫浸润和激活。因此，我们提出miRNA92a和PTEN-PI3K-KLF2信号网络可作为创新精准药物的靶点，以减少T1D胰岛自身免疫。
