A Distinct Inhibitory Function for miR-18a in Th17 Cell Differentiation.

ABSTRACT: Th17 cell responses orchestrate immunity against extracellular pathogens but also underlie autoimmune disease pathogenesis. In this study, we uncovered a distinct and critical role for miR-18a in limiting Th17 cell differentiation. miR-18a was the most dynamically upregulated microRNA of the miR-17-92 cluster in activated T cells. miR-18a deficiency enhanced CCR6+ RAR-related orphan receptor (ROR)?t+ Th17 cell differentiation in vitro and increased the number of tissue Th17 cells expressing CCR6, ROR?t, and IL-17A in airway inflammation models in vivo. Sequence-specific miR-18 inhibitors increased CCR6 and ROR?t expression in mouse and human CD4+ T cells, revealing functional conservation. miR-18a directly targeted Smad4, Hif1a, and Rora, all key transcription factors in the Th17 cell gene-expression program. These findings indicate that activating signals influence the outcome of Th cell differentiation via differential regulation of mature microRNAs within a common cluster.

SUBMITTER: Montoya MM 

PROVIDER: S-EPMC5508756 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature